Food Chemistry

This work studies the physicochemical properties of quinoa flour and isolated starch. Starch in the seed forms clusters rich in amylopectin that are immersed in a matrix with spherical and polygonal shapes in the submicron scale. The isolated quinoa starch is rich in Sulphur and Magnesium. The quinoa flour has a higher content of protein, carbohydrates and lipids than isolated starch. Water absorption and water solubilized indexes of starch exhibited high values that could had originated by the extraction method. The broad peaks found for the X-ray patterns of isolated quinoa starch indicate that amylose and amylopectin are composed by nanocrystals, according to the PDF-4+2019 software. The viscosity of isolated starch had a higher value than flour; therefore, the quinoa starch could be used as a thickener in different formulations with the advantage of keeping a significant presence of minerals which are important to the human health.

There is general interest in strategies to control polyphenol oxidase (PPO)-initiated enzymatic browning because it is often associated with declining food quality. Cyclodextrins are cyclic glucan oligosaccharides that form inclusion complexes with a number of PPO substrates. This study focuses on the effect of β-cyclodextrins (βCyD) on PPO-catalyzed reactions. Potato enzyme extracts and semi-purified potato PPO served as enzyme sources. Substrates included phenolics endogenous to potatoes. Reaction time-courses were followed spectrophotometrically; rates were compared by analysis of variance. Extents of βCyD inhibition of PPO-catalyzed reactions are shown to be substrate specific and can be quantitatively accounted for based on degrees of βCyD substrate sequestration. There was no evidence for direct irreversible βCyD inactivation of potato PPO. An apparent “direct PPO inactivation” by βCyD is shown to result from a sequence of sequestration-dependent reactions that occur in commonly employed assay systems for the quantification of PPO in fruits and vegetables.

In this study, sacha inchi oil (SIO) (Plukenetia volubilis L.) was microencapsulated via complex coacervation of ovalbumin (OVA) and sodium alginate (AL), and the microcapsule properties were characterized. The omega-3 content in the SIO was evaluated after in vitro gastric simulation and microencapsulation. The coacervate complex between OVA and AL was evaluated based on electrostatic interactions and developed for use as a wall material via the SIO microencapsulation process. The best mass ratio for the biopolymers (OVA:AL) was 4:1 at pH 3.8, and the complex exhibited a thermal resistance at 189.86 °C. The SIO microcapsules showed a high encapsulation efficiency of approximately 94.12% in the ratio (OVA:AL) of 1:1. Furthermore, microencapsulated SIO presented resistance under gastric conditions with a low release of acyl (ω-3) units. These results demonstrate that it is possible to use OVA:AL as encapsulating agents to protect bioactive compounds and to improve the thermal behavior of microcapsules.

A scallop midgut gland certified reference material, NMIJ CRM 7520-a, was developed for validation and quality assurance during the inspection of shellfish for diarrhetic shellfish toxins. The candidate material was prepared by using naturally-toxic and nontoxic boiled midgut glands spiked with okadaic acid (OA). The homogeneity and stability of the material were found to be appropriate. For the characterization of OA and dinophysistoxin-1 (DTX1), nine participants were involved in a co-laboratory study based on the Japanese Official Testing Method, where the compounds were assayed by liquid chromatography-tandem mass spectrometry following alkaline hydrolysis. The analytical values were obtained by the standard addition method with a standard spiking solution calibrated using the standard-solution certified reference materials OA and DTX1. The certified concentrations with expanded uncertainties (coverage factor k = 2, approximate 95% confidence interval) were determined to be (0.205 ± 0.061) mg/kg for OA and (0.45 ± 0.11) mg/kg for DTX1.

Typical ketone flavours (with variations in chain length, position and number of keto group, branched chain) were selected to investigate the effect of molecule structure of ketones on their interactions with myofibrillar proteins (MPs). Results showed that 2,3-pentanedione quenched the fluorescence of MPs more effectively than 2-pentanone and 3-pentanone due to the number of keto group. There was no significant difference between 5-methyl-2-hexanone and 2-heptanone, which was attributed to their similar molecular size and polarity. The quenching effect of homologous ketone flavours increased with carbon chain growth due to the higher hydrophobic interaction. Dynamic quenching played a major role in the fluorescence quenching process of MPs by 2-pentanone, 3-pentanone, 5-methyl-2-hexanone, 2-heptanone and 2-octanone. The α-helix content decreased gradually with the increase of ketones concentration. Results of GC/MS were in accordance with the fluorescence quenching analysis generally, whereas 2,3-pentanedione and 2-nonanone exhibited some differences due to their higher steric hindrance effects.

We investigated the allergenicity, digestibility and functional properties of whey protein isolate (WPI) after covalent conjugation with chlorogenic acid (CHA). The covalent conjugation of CHA may cause an unfolded protein structure. The WPI–CHA conjugate showed lower IgE binding capacity but higher intestinal digestibility than unmodified WPI. Furthermore, after digestion, the IgE binding capacity of β-lactoglobulin and α-lactoalbumin was lower in the digested WPI–CHA conjugate than digested WPI. Moreover, the solubility, emulsifying activity, foaming properties and antioxidant capacity of WPI were enhanced by covalent conjugation of CHA. Covalent conjugation with CHA might reduce the allergenicity in vitro of WPI by improving the functional properties of the protein.

This study aims to investigate the postharvest physiology and texture of garlic cloves packaged in polyethylene terephthalate (PET), polyethylene (PE), aluminized kraft paper (AKP), single kraft paper (SKP), and mesh bag. Germination rate, electrical conductivity, respiration intensity, water content, and texture were determined during 180 d storage at −2 °C. Results showed that the germination of garlic cloves packaged in PET, PE, and AKP was effectively inhibited during storage. PE effectively reduced the degree of damage to the cell membranes of the garlic cloves. PE and SKP significantly inhibited respiratory intensity during storage. Garlic cloves water content did not change significantly in 90 d storage which packaged in PE and SKP. PE exhibited better effect on the texture and freshness of garlic cloves than the other materials. In conclusion, PE is the best packaging material for maintaining the quality attributes and extending the shelf lives of garlic cloves.

The objective of this study was to develop an accurate and fast method to determine malondialdehyde (MDA) levels in raw and processed meat. This method is based on extraction with trichloroacetic acid (TCA), reaction with 2-thiobarbituric acid (TBA) and quantification with ultraperformance liquid chromatography with a fluorescence detector (UPLC-FLD) with ʎ_excitation = 530 nm and ʎ_emission = 550 nm and with a diode array detector (UPLC-DAD) with ʎ_absorbance = 532 nm. The method tested was compared with the TBARS spectrophotometric method with ʎ_absorbance = 532 nm. The concentration of MDA was similar for most of the matrices in both UPLC methods, except for cooked ham and frankfurter sausage. The TBARS spectrophotometric method overestimated the MDA concentration in all the matrices. Therefore, the use of both chromatographic methods, especially UPLC-FLD, to determine MDA would be more advisable than the classic TBARS method to avoid overestimation in meat and processed meat products.

In this study, subcritical water extraction (SWE), SWE in aqueous citric acid (pH 5.0) (SWEC), and ultrasound-assisted SWEC (USWEC) were used to extract soluble dietary fiber (SDF) from wheat bran. Results showed that SWE-based methods significantly influenced the physicochemical, functional, and biological properties of the SDF. The fraction SDF-III attained via USWEC had higher SDF yield (46.30%) and carbohydrate content (82.91%), and lower weight-average molecular weight (65.2 kDa) and particle size (1.17 μm), and looser and more porous surface structure, compared with the SDF-I and SDF-II obtained by SWE and SWEC, respectively. USWEC increased the thermal stability and homogeneity of SDF-III but decreased its apparent viscosity and dynamic viscoelasticity. Moreover, the SDF-III exhibited more significant antioxidant and α-amylase inhibitory activities in vitro than SDF-I and SDF-II. Therefore, the USWEC technique had a greater potential for the highly-efficient production of SDF from wheat bran.

The aim of the present study was to explore the underlying mechanisms involved in anthocyanin biosynthesis in purple, blue, and white barley using quantitative proteomics analysis. We identified the differences in protein expression and related functions involved in anthocyanin biosynthesis in purple, blue, and white barley (named H, M, and L groups, respectively, based on their anthocyanin content) using TMT-liquid chromatography/mass spectroscopy-based proteomic methods. Totally, 297, 300, 254, and 1421 differentially expressed proteins (DEPs) were found in H vs. L, H vs. M, L vs. M, and H vs. L vs. M groups, respectively. Six clusters of proteins from the 1421 DEPs were mainly involved in carbon metabolism, amino acid and secondary metabolite biosynthesis, and metabolic pathways. Several proteins were validated using parallel reaction monitoring. The proteins involved in amino acid biosynthesis, carbon metabolism, metabolic pathways, and phenylpropanoid biosynthesis were responsible for the color differences in the three barley varieties.

Glycoside hydrolase family 8 (GH8) includes endoglucanases, lichenases, chitosanases and xylanases, which are essential for polysaccharides breakdown. In this work, we studied a thermally stable GH8 from the cellulose synthase complex of Enterobacter sp. R1, for deconstruction of β-glucans. The biochemical characterization of the recombinant GH8ErCel showed high specificity towards barley β-glucan and lichenan and lower activity on carboxymethylcellulose and swollen cellulose, yielding different length oligosaccharides. By molecular modeling, six conserved subsites for glucose binding and some possible determinants for its lack of xylanase and chitosanase activity were identified. GH8ErCel was active at a broad range of pH and temperature and presented remarkable stability at 60 °C. Additionally, it hydrolyzed β-glucan from oat and wheat brans mainly to tri- and tetraoligosaccharides. Therefore, GH8ErCel may be a good candidate for enzymatic deconstruction of β-glucans at high temperature in food and feed industries, including the production of prebiotics and functional foods.

We established a novel Dianhong black tea grades discriminant analytic technique based on a fluorescence image along with carbon quantum dots (CDs) as fluorescent probes. Different grades of Dianhong black tea contain different various amounts of tea polyphenols. Tea polyphenols can quench the fluorescent intensity of CDs, resulting in different fluorescent peaks; Dianhong black tea grades can then be discriminated through the use of principal component analysis and Bayesian analysis. Compared with the additional data processing required in other methods, the advantage of our method is that the fluorescence curve can be used directly, and it achieves satisfactory results. We firstly used CDs combined with chemometrics to identify eight grades of Dianhong black tea, and we also provide a new method that improves the identification rate using nanotechnology to avoid performing complex data processing.

Plant species differ greatly in their ability to acclimatise to and survive, cold stress. Normally, potato tubers are stored at low temperatures (below 10 °C) to delay sprouting. In this research, combined transcriptomic and proteomic analysis was conducted on potato tubers stored at 15 °C, 4 °C and 0 °C to investigate the mechanism of cold responses during postharvest storage. Results showed that soluble sugars were accumulated under low temperatures, regulating by granule-bound starch synthase 1, beta-amylase, invertase inhibitor and fructokinase. In addition, fifteen heat shock proteins (Hsps), including three Hsp70s, two Hsp80s, one Hsp90, one Hsp100 and eight small Hsps, were induced by low temperatures, which may act individually or synergistically to prevent physiological or cellular damage from cold stress in postharvest potato tubers. This research provided general information of sugar accumulation and defense response in potato tuber under cold storage.

A robust and sensitive method utilising a hybrid ion chromatography tandem mass spectrometry system (IC-MS/MS) for the simultaneous determination of nine (9) highly polar anionic pesticides (chlorate, ethephon, fosetyl aluminium, glufosinate, glyphosate, N-acetyl AMPA, N-acetyl glyphosate, perchlorate and phosphonic acid) in fruit and vegetables is described. Mean recoveries (n = 6) at two fortification levels ranged from 83 to 112% with %CVs in the range 3–14%. The linearity range was 0.005–0.4 mg kg⁻¹ and R² values were >0.99 and the sensitivity of the method allowed (20× or 30×) dilution of samples. Provision of qualitative determination of aminomethylphosphonic acid (AMPA) was also facilitated via minor modification of the chromatographic conditions. Compliance with method validation criteria, survey results from the statutory UK/EU Pesticide Residues in Food 2018 programmes i.e. pea, pineapple, melon and successful z-scores for a UK proficiency testing scheme sample (ethephon in pineapple) demonstrate successful application of this IC-MS/MS method.

Scotch Whisky has been analysed as a complex mixture in its raw form using high resolution Nuclear Magnetic Resonance (NMR) and previously developed water and ethanol suppression techniques. This has allowed for the positive identification of 25 compounds in Scotch Whisky by means of comparison to reference standards, spike-in experiments, and advanced 1D and 2D NMR experiments. Quantification of compounds was hindered by signal overlap, though peak alignment strategies were largely successful. Statistical total correlation spectroscopy (STOCSY) yielded information on signals arising from the same compound or compounds of similar origin. Statistical analysis of the spectra was performed using Independent and Principal Components Analysis (ICA, PCA) as well as Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA). Several whisky production parameters were successfully modelled, including blend or malt status, use of peated malt, alcohol strength, generic authentication and maturation wood type, whilst age and geographical origin could not be modelled.

Effect of phlorotannins (PT) treatments on the ployhenoloxidase (PPO) activity and quality changes of Pacific white shrimp during a 16-day period of storage in ice were studied. Among seaweeds, Sargassum tenerimum had the highest amount of PT (10.00 mg phloroglucinol/g), PPO inhibitory activity (71.94%) and therefore selected for PT extraction. The shrimp treated with 5% PT (w/v) showed the least melanosis score, pH, TVB-N values and lipid oxidation among all treatments throughout the iced storage. Lower counts of mesophilic and psychrotrophic bacteria (1–2 log CFU/g) were obtained with 5% PT treatment compared to the control at the last day of storage (P < 0.05). Sensory evaluation proved that 5% PT treatment could cause a 4-days increase in the shelf-life of shrimp compared to the control, PT1% and PT2% treatments. Therefore, 5% phlorotannins from S. tenerimum could be used as a safe melanosis inhibitor for the treatment of shrimp.

In this study, the ultrasonic dishwasher was used to remove five pesticides known to be frequently used on rape and grape. As compared with normal water washing, washing with the ultrasonic dishwasher was demonstrated to be more effective for pesticides removal, achieving removal rates between 14.7% and 59.8% on rape, and between 72.1% and 100% on grape. However, there were significant differences in order of the removal rate of five pesticides on rape and grape. From the adsorption experiments and analysis via Freundlich equation, the adsorption index (n, 0.551–1.056 on rape and 0.362–1.478 on grape) and adsorption coefficient (K_F, 10^−2.47–10^−1.65 and 10^−3.64–10^−1.56 (mg·dm⁻²)/(mg·L⁻¹)⁻ⁿ on rape and grape) were obtained. Taken together with the observation of the matrix surface by scanning electron microscopy and the evaluation of the physicochemical properties of pesticides, the different pesticides removal may be related to surface structure of the matrix.

Development of an effective sensor for sensing glucose in commercially available “sugar free” food products is important as people are becoming diabetic health conscious. Although multi-walled carbon nanotubes (MWCNTs) possess interesting electrical properties, their hydrophobic nature limits their applications. Their hydrophilicity can be improved through modification. In the present study, Inulin, that was isolated from Allium sativum L. using hot water diffusion and incorporated with titanium dioxide (TiO₂), was used for the modification of MWCNTs. The as-synthesized MWCNT-Inulin-TiO₂ bio-nanocomposite immobilized with glucose oxidase (GOx) was incorporated into the carbon paste matrix and was utilized for the sensing of glucose in food products. Differential pulse voltammetric studies revealed that the fabricated electrode demonstrated good linear range (1.6 nM to 1 μM) and was sensitive to nanomolar concentrations of glucose with a very low limit of detection up to 0.82 nM and exhibited a long term stability of 150 days.

Starch digestibility and polyphenol content were investigated in six (white, red and purple) Thai rice varieties. Total phenolic content (TPC), total anthocyanin content (TAC), amylose content, gelatinization parameters and in vitro digestibility were determined. Purple and red rice varieties were found to have the highest levels of TPC, TAC and amylose content. TAC was not detected in white rice, while purple rice had the highest values. Gelatinization parameters were determined using differential scanning calorimetry. Red rice (Sung Yod) showed the highest gelatinization enthalpy. Non-pigmented rice (Hom Mali) in both purified starch and flour showed the highest starch digestibility, with a total starch digestibility of 76.85% and a digestion rate of 0.25 min⁻¹. In contrast pigmented rice varieties showed lower starch digestibility. These results suggest that pigmented rice varieties are a source of phenolics and anthocyanin and also a possible good source of low digestible starch to develop as functional food products.

The effects of co-digestion of red cabbage with carrot, baby spinach and/or cherry tomato on the bioaccessibility of anthocyanins and carotenoids such as α-carotene, β-carotene, lutein and lycopene were examined using a simulated in vitro gastro-intestinal digestion model. The individual vegetables and their mixtures were digested with and without added a standardised salad dressing. Bioaccessibility of total anthocyanins was enhanced by 10–15% (p < 0.05) when red cabbage was co-digested with the carotenoid-rich vegetables, except with carrot. In contrast, the co-digestion of red cabbage with carrot decreased bioaccessibility of total carotenoids by 21–33% (p < 0.05), and with cherry tomato by 42–56% (p < 0.05). The bioaccessibility of a given carotenoid varied depending on the vegetable matrix. Among the tested vegetable mixtures, red cabbage and baby spinach when co-digested demonstrated that anthocyanins and carotenoids were equally bioaccessible (total anthocyanin bioaccessibility of 62–66% and total carotenoid bioaccessibility of 66%).

The chemical and sensory profiles of wines prepared from Cabernet Sauvignon grapes at different ripening stages vary greatly. Here, the soluble cell wall carbohydrate (SCWC) and phenolic profiles of wines were analyzed in parallel with the sensory evaluation of their mouthfeel and taste characteristics. Both SCWCs and phenolic compounds correlated with wine mouthfeel. When analyses were extended to specific classes of cell wall carbohydrates, it was shown that rhamnogalacturonan I/II, arabinan, arabinogalactan types I and II and xyloglucan from grapes were the key determinants of overall mouthfeel descriptors, particularly viscosity, astringency and roughness, whereas heteromannan from grapes was associated with mouth coating and chalkiness. A perceived sour taste was notably associated with higher homogalacturonan contents. This finding provides insights into the contributions of non-phenolic compounds to wine mouthfeel. The data provide opportunities for the development of simple monosaccharide marker assays to monitor major mouthfeel characteristics in red wines.

Extra virgin olive oil (EVO) is among the most counterfeit foodstuffs in the present market. The Italian production is with no doubt one of the most valuable and therefore mostly counterfeit, due to the difficulty in checking the geographic provenance of olives. In order to provide a way for verifying the provenance of EVO, the role of microelements and, in particular, of lanthanides in the oil production chain has been studied. The distribution of lanthanides as determined by means of ICP-MS analysis appeared to provide a good tool for tracing the EVO production chain. Lanthanides and other microelements were then used for distinguishing a particularly prised EVO production from Liguria (northwestern Italy) made from Taggiasca olive variety, verifying that this production can be easily authenticated on the base of these chemical descriptors.

This work aimed to evaluate the efficacy of protein hydrolysates from bighead carp gill in inhibiting protein oxidation and quality loss in surimi. Firstly, antioxidant activity of hydrolysates in vitro was assessed, then 1%, 2% hydrolysates with better antioxidant activity and 4% sucrose were added to surimi respectively and stored at −18 °C for 4 months. Peptide sequences of above hydrolysates were also identified. The results suggested that hydrolysates of neutral protease had excellent 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability (42.93%) and Fe²⁺-chelating activity (73.27%). Compared with surimi without treatments, surimi with hydrolysates had higher sulfhydryl and salt-soluble protein concentrations, greater Ca²⁺-ATPase activity, lower disulfide bonds, carbonyls and hydrophobicity, as well as better gel strength and texture (p < 0.05). This study demonstrated that gill hydrolysate had antioxidant and dose-dependent cryoprotective effects on surimi that were comparable to the effects of sucrose, representing it as an alternative to sugar cryoprotectants in surimi industry.

Heavy traces metals may be present in honey being their detection very important for the quality control and it also serves as an indicator of environmental pollution. A new methodology for lead traces determination has been developed based on the quenching effect of the metal on fluorescent emission of 8-hydroxyquinoline and o-phenanthroline at λ_em = 360 nm (λ_exc = 250 nm). Experimental variables that influence on fluorimetric sensitivity were optimized by uni-variation assays. The calibration graph using zero^th order regression was linear from 0.105 µg L⁻¹ to 51.8 µg L⁻¹, with correlation coefficient better than 0.998. Under the optimal conditions, the limits of detection and quantification were of 0.035 µg L⁻¹ and 0.105 µg L⁻¹, respectively. The trueness of the methodology was assessed trough parallel samples analysis by ICP-MS. The proposed method showed good sensitivity, adequate selectivity with good tolerance to foreign ions, and was applied to the determination of lead trace amounts in honey from San Luis city (Argentina) with satisfactory results.

This research investigated the effect of pH on forming electrostatic complexes between lentil protein isolate (LPI) and a range of anionic polysaccharides [carboxymethyl cellulose (CMC), gum Arabic (GA), alginate (AL), and ι-carrageenan (CAR)] at 4:1 LPI-polysaccharide mixing ratio, and their resulting emulsifying abilities. Maximum optical densities were found to be 0.486, 0.716, 0.310, and 0.190 for LPI-CMC, LPI-GA, LPI-AL, and LPI-CAR, respectively indicating the level of aggregate size and growth. LPI-CAR emulsion displayed the highest emulsion stability (ES) because of its higher continuous phase and emulsion viscosities, lower mean droplet sizes, and negatively charged droplets. They also formed much smaller complexes within solution due to their high negative charge. All other LPI-polysaccharide systems formed less stable emulsions than LPI alone due to the larger sizes of both complexes and oil droplets.

Fumonisin B1 (FB1) is a carcinogenic mycotoxin produced by Fusarium species contaminating maize. At present, fumonisin determination is performed using costly and demanding chromatography techniques or immunoassays. Recently, a molecularly imprinted polymer nanoparticles (nanoMIPs) – based assay (MINA) has been developed for FB1 detection. Herein, we have applied MINA for the determination of FB1 in naturally contaminated maize samples and results were compared with those obtained with ELISA and a reference HPLC method (AOAC No. 2001.04). The nanoMIPs as a recognition element mimicking antibodies used in ELISA were produced by solid phase synthesis and used in MINA for FB1 determination in 53 maize samples. As a result, 18 maize samples were contaminated with FB1 at levels higher than 0.25 mg/kg. Fumonisin concentrations from samples measured by MINA were well correlated with those using ELISA and HPLC. Therefore, MINA could be used as an alternative technique for FB1 determination in maize.

This manuscript is a bibliographic review about analyses of different classes of pesticide in fruits using QuEChERS as sample preparation methodology. The aim is to clarify different trends and facilitate decision-making by the scientific community in order to carry out further studies in this field. It is well known that different countries have different pesticides regulations for maximum level of pesticide residue permitted. The comparative analysis amongst the main producer countries reveals that for some fruits they are not studied enough. Recent improvements to QuEChERS make it possible to minimize the pesticides instability due the matrix pH, and achieving cleaner extracts. Regarding the detection systems, the tandem MS are preferred once they have high sensitivity and selectivity, although traditional techniques (GC-ECD and HPLC-DAD) are still commonly used due to their accessibility and good sensitivity to some pesticides. Also, studies involving metabolites usually show that they are more toxic than their precursor compounds.

Plant extracts from rosemary (RE), green tea (GTE), and maté (ME) were compared for the protection against iron-induced oxidation in porcine homogenates at total phenolic concentrations from 25 to 250 ppm. Lipid oxidation as indicated by TBARS was in all cases sufficiently suppressed, especially for RE. Hydrophobic RE retarded overall oxidation in the homogenates with an inverted dose-dependent response. Optimum delay of oxygen consumption was found at the lowest concentration applied, similar to protection against thiols and formation of protein radicals as measured by ESR, whereas the high concentration increased oxygen consumption and caused additionally thiol loss possibly due to thiol-quinone interactions, generating protein-phenol complexes. Hydrophilic ME or GTE increased the initial oxygen consumption rate as an indication of prooxidant activities at elevated concentrations. However, they were found to protect myoglobin and protein at those high concentrations with GTE being more efficient, possibly due to better chelation effect.

Edible packaging films play an important role in extending the shelf life of food products. In this work, the properties of cellulose nanofiber (CNF) reinforced hemicelluloses/chitosan-based edible films with xylooligosaccharides (XOS) have been evaluated. Results showed that the tensile strength (TS) of the film can be increased by 2.5 times with adding 5 wt% CNF. Incorporating 1.79–7.18% XOS into hemicelluloses-chitosan matrix only caused slightly higher water vapor permeability, and the composite films exhibited good hydrophobicity, thermal stability, and high transparency. The hemicelluloses/chitosan films with 1.79–5.38% XOS had higher TS (42.7–50.7 MPa) and lower oxygen permeability (OP, 4.95–5.06 cm³ μm/m²·day·kPa) than those containing 7.18% XOS. Additionally, ∼92.6% XOS in films can be released in simulated gastric fluid within 60 min. Overall, XOS (1.79–5.38%) with prebiotic properties can be added to films successfully to improve the functionality and the films were fit for food-packaging where high TS and low OP are required.

The bioavailability of the pyridoxal (PL), pyridoxine (PN), and pyridoxamine (PM) forms of vitamin B₆ is different, considering that their bioaccessibility in baby foods is important for infant and young children’s nutrition. The aim of this study was to determine and evaluate the bioaccessibility of the PL, PN, and PM forms of vitamin B₆ in cereal-based baby foods an in vitro digestive system. In this study, the PL, PN, and PM forms of vitamin B₆ were determined using HPLC in 13 cereal-based baby foods. The average bioaccessibility of the PL, PN, and PM forms in gastric pH 1.5 were 53%, 76%, and 50%, respectively. When the gastric pH was 4, the average bioaccessibility of PL, PN, and PM were 38%, 67%, and 36%, respectively. As observed in this study, the bioaccessibility of the PL, PN, and PM forms of vitamin B₆ in baby foods is lower in both gastric pHs.

The oral breakdown, sensory properties, and volatile release during mastication of white bread were investigated. The results of correlation analysis for white bread’s physical properties and it’s oral physiological parameters during chewing have elucidated that bread’s physical properties determined the oral processing behavior. During chewing of white bread, 15 dominant ions with regularly changing patterns were monitored by proton transfer reaction–mass spectrometry (PTR–MS). These dominant ions derived from 32 volatile compounds were further confirmed by pure standards. Partial least squares regression (PLSR) analysis was used to explore the positive correlations between the sensory analysis and the dominant aroma compounds. Results have shown that 9 aroma compounds were predicted as the potent odorants contributing to the changes in aroma profiles. Finally, 3-hydroxy-2-butanone, 2-methyl-1-propanol, and heptanoic acid were confirmed as the key aroma compounds contributing to the changes in aroma profiles of white bread before and after chewing.

The effect of microwave irradiation-retrogradation (MIR) treatment on the physicochemical properties and in vitro digestibility of corn starch (A-type crystallinity), potato starch (B-type) and chestnut starch (C-type) were evaluated. After MIR treatment, the amount of resistant starch (RS) increased and rapid digestible starch (RDS) decreased along with the retrogradation time in all three starches. The degree of retrogradation (DR) of starch was significantly positive correlated with amylose and RS content. All three starches subjected to MIR treatment exhibited a B-type crystalline structure. With the increase in retrogradation time, starch granules became more orderly. The DR was significantly positively correlated with relative crystallinity of X-ray pattern, T_o, ΔH of thermal properties, and the Fourier transform infrared ratio of 1047/1022 cm⁻¹ of starch. The results indicated that MIR treatment is a good industrial method for preparing low digestive starch and retrogradation time is an important parameter for the process.

Roasted cotyledons of the Chilean hazelnut (Gevuina avellana) are appreciated as snacks. The aim of our work was to assess the fatty acid, oxylipin and phenolic composition using gas chromatography (GC) coupled to mass spectrometry (MS), ultra- high performance liquid chromatography (UHPLC) coupled to MS and HPLC coupled to diode array detector (HPLC-DAD). Additionally, various antioxidant activities were assessed. The inhibition of α-glucosidase, α-amylase, lipase, cyclooxygenases-1 and -2 (COX-1/COX-2), and lipoxygenase was determined.

The main fatty acids were oleic and 7-hexadecenoic acids. Eight phytoprostanes and three phytofurans were identified and quantified. Hydroxybenzoic and hydroxycinnamic acids were the main phenolic compounds. Oils showed antioxidant activity determined by EPR, and inhibition of COX-1/COX-2. The statistical analysis showed that the roasting does not affect the composition of the samples. The occurrence of oxylipins in this species is reported for the first time. Chilean hazelnuts can be considered a source of health promoting compounds.

Lipids are only minor wheat flour constituents but play major roles in bread making (BM). Here, the importance of a well-balanced lipid population in BM was studied by applying a lipase from Fusarium oxysporum in the process. Monogalactosyldiacylglycerols and N-acyl phosphatidylethanolamines were the most accessible lipase substrates. Hydrolysis thereof into their corresponding lysolipids was largely if not entirely responsible for loaf volume increases upon lipase application. Degradation of endogenously present lipids and enzymatically released lysolipids caused loaf volume to decrease, confirming that an appropriate balance between different types of lipids is crucial in BM. For optimal dough gas cell stability, the level of lipids promoting lamellar mesophases and, thus, liquid condensed monolayers needs to be maximal while maintaining an appropriate balance between lipids promoting hexagonal I phases, non-polar lipids and lipids promoting hexagonal II or cubic phases.

Elemental profiles of wines have been used successfully to distinguish their geographical provenience around the world; however, underlying mechanisms are poorly understood. In this study, Ba, Ca, Mg, Mn and Sr contents were determined in 215 wines from several West European wine-growing areas using an easy-to-perform analysis based on ICP-OES. Major environmental and wine-making parameters (soil type as “calcareous” or not, rainfall, temperature and wine color) were used to explain variations within the dataset.

The combined effects of wine-making processes (expressed by wine color) and soil type explained 28.5% of total variance. The effect of climatic conditions explained 24.1% of variance and could be interpreted as intensity of drought stress.

Finally, carbonate occurrence in soils and climatic conditions systematically influenced the elemental composition of the wines. These findings provide insights into the mechanisms underlying elemental fingerprinting and allow prediction of which wine-growing regions can easily be distinguished based on elemental profiles as a marker of the terroir in viticulture.

Thermal processing methods have important effects on food lipids. In this work, ultra-high-performance liquid chromatography-Q-Extractive Orbitrap mass spectrometry and lipidsearch software were applied to analyze effect of three types of thermal processing methods on the lipidomics profile of tilapia fillets. A total 15 classes of compound lipids (Cer, DG, LPC, LPE, LPG, LPI, LPS, PC, PE, PG, PI, PS, SM, So, TG) were analyzed. In addition, free DHA, EPA, and ARA were also identified. Furthermore, statistical analyses of these lipids were performed based on MetaboAnalyst software. The results demonstrated three types of thermal processing methods had different effects on lipidomics profile differences of tilapia fillets. A total of eight lipid species variables (LPS, LPG, LPI, DG, LPC, TG, LPE, and Cer) and 137 individual lipids variables showed significant differences among raw, steamed, boiled, and roasted tilapia fillets. This work could provide useful information for aquatic product processing and lipidomics.

Colour removal in raw sugar remains a crucial but expensive process in the sugar industry. In this report, permanganate (MnO₄⁻) oxidation is explored as an alternative method to remove colour-inducing constituents in sugar cane juice/produced raw sugar. Experiments indicated alum, an inexpensive coagulant, was able to remove residual Mn species produced after MnO₄⁻ treatment. The optimal dosages of MnO₄⁻ and alum for decoloration of a 17 wt% raw sugar solution (70 °C) was found to be 4 mM and 2 g/l, respectively. Removal of colour and Mn removal were further improved at ambient temperature. Sucrose, the major component of raw sugar, was not affected during treatment with MnO₄⁻ and alum. Two-phase kinetic behaviour for MnO₄⁻ oxidation was observed, where an initial rapid oxidation phase is followed by a second slower reaction phase. These results suggest permanganate oxidation is a promising alternative for accomplishing the decoloration of raw sugar solutions.

Lactoferrin (LF) is a glycoprotein that serves as a potential vehicle for small bioactive molecules in food. In an effort to improve this functionality, the kinetic and thermodynamic interaction of LF with naringin (NR) was studied by surface plasmon resonance (SPR). The results demonstrated that the association rate constant between LF and NR was 5.00 × 10⁴ M⁻¹ s⁻¹, while the dissociation rate of the complex was 0.36 s⁻¹, at 25 °C. The stable complex predominated over free molecules (ΔG25°C0=−29.35 kJ mol⁻¹), and the binding constant was 1.39 × 10⁵ M⁻¹, at 25 °C. The association of LF and NR to form an intermediate complex occurred in multi-steps. Nevertheless, the intermediate complex formation from the dissociation of the stable complex occurred in a single step with the activation energy independent of temperature. This study provides an important basis to explore LF as a vehicle for bioactive molecules.

Hyperbranched rolling circle amplification (HRCA) with a padlock probe (PLP) targeting the α-amanitin (α-AMA) gene, as a screening tool for the universal identification of lethal amanitas, was established in this study. With the isothermal HRCA assay, all of the lethal Amanita species tested from Phalloideae (10) were positive, while the non-Phalloideae Amanita species (15) and three amanitin-containing Lepiota and Galerina species were negative. Furthermore, the PLP based on α-AMA sequences from lethal Amanita species was effective for Amanita α-AMA, but not Amanita β-AMA or non-Amanita α-AMA. HRCA sensitivity was 100-fold higher than conventional PCR with a detection limit of 100 copies (recombinant plasmid containing α-AMA), and 0.2% lethal amanitas could be detected in dry mushroom blends. The HRCA method presented provided a rapid, specific, sensitive and low-cost identification tool for lethal amanitas.

A wash-free and label-free colorimetric biosensor for the amplified detection of aflatoxin B1 (AFB1) has been constructed by the integration of an ingenious hairpin DNA probe with exonuclease III (Exo III)-assisted signal amplification. The presence of the AFB1 activates the continuous cleavage reactions by Exo III toward a hairpin probe, resulting in the autonomous accumulation of numerous free G-quadruplex sequences, which can catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) by H₂O₂ to produce a colorimetric response. The naked-eye biosensor is ultrasensitive, enabling the visual detection of trace amounts of AFB1 as low as 1 pM without instrumentation. The sensor is robust and can work even when challenged with complex sample matrices such as peanut samples. With the advantages of simple operation, wash-free and label-free format, visible and intuitive output, and low cost, the naked-eye based colorimetric biosensor is expected to have potential applications for in-field detection of AFB1.

A dietary fibre prepared from sugarcane stalk was compared with psyllium husk and wheat dextrin. In contrast to the other dietary fibres, sugarcane fibre was found to contain significant amounts of insoluble dietary fibre (73–86%), lignin (18.66–20.23%), and rare minerals such as chromium (0.67–2.54 mg/100 g) and manganese (1.07–2.34 mg/100 g). Analysis of the ethanol extract also detected compounds with antioxidant activity. Characterisation of five sugarcane fibres prepared from selected strains, harvest periods (growth or storage phase), and processing conditions showed these factors influenced the final composition. Furthermore, using in vitro digestion, we found that potassium, magnesium, chromium, and zinc in were bioaccessible in sugarcane samples. Also, sodium was shown to bind to the sugarcane fibre potentially indicating bile salt binding activity. Results from this study support the use of sugarcane as a source of dietary fibre in functional foods.

In this work, 18 gluten-free flours (prepared from cereals, pseudocereals and legumes), differing in pigmentation, were screened for their phenolic profiles, cooked and, then, subjected to digestion and large intestinal fermentation in vitro. A combined targeted/untargeted metabolomic approach was used to elucidate the microbial biotransformation processes of polyphenols following digestion. This preliminary work demonstrated an increase in 3,5-dihydroxybenzoic acid (on average from 0.67 up to 1.30 μmol/g dry matter) throughout large intestinal fermentation of pseudocereals (esp. quinoa), due to their high alkylresorcinol contents. Isoflavones were converted into equol- or O-desmethylangolensin- derivatives, whereas anthocyanins were degraded into lower-molecular-weight phenolics (i.e., protocatechuic aldehyde and 4-hydroxybenzoic acid, with the latter exhibiting the highest increase over time). A decreasing trend was observed for antioxidant activities (i.e., FRAP and ORAC values) moving from digested to faecal fermented samples. These findings highlight that gluten-free flours are able to deliver bioaccessible polyphenols to the colon.

The aim of this study was to dissociate the effect of atomization from that of heating during the spray-drying of Low Methoxyl (LM) pectin/sodium caseinate complexes. The properties of these complexes were studied by measuring turbidity, particle size distribution, zeta-potential, as well as surface hydrophobicity of caseinate within the formed complexes. The results showed that the spraying step had a significant effect on the charge and the size of the complexes. In fact, the application of atomization resulted in the dissociation of caseinate/pectin aggregates especially for high pectin concentrations. Besides, the analysis of the surface hydrophobicity of caseinate indicated that complexation with high concentrations of pectin is able to protect the structure of the protein against heat denaturation. This study allowed a better understanding of the influence of atomization and heat treatment (during the dehydration step) on the molecular interactions within caseinate/pectin complexes.

In this work, three versions of the QuEChERS method (original, AOAC 2007.01 and CEN 15662) were evaluated for the extraction of 38 multiclass pesticides from a mixture of five dried fruits: (strawberry, blackberry, passion fruit, pineapple and grapes) prior to their gas chromatography tandem mass spectrometry analysis. Among them, the AOAC 2007.01 method provided the best results in terms of lower amount of matrix co-extractives, matrix effect, extraction efficiency and precision. Its application to the analysis of the same pesticides in the individual dried fruits provided good recovery (between 70 and 120%) and relative standard deviation values (<20%) for most pesticides at three spiked levels. Matrix effect assessment revealed the necessity of taking into account such effect. Matrix-matched calibration data were also satisfactory for all analytes and matrices being the R² ≥ 0.9900 and the lowest calibration level 5 µg/kg, which is lower than the agreed limit set at 10 µg/kg for monitoring purposes in food applications. Three samples of each type were also analysed, finding residues of metalaxyl, chlorpyrifos and iprodione in some of them.

The intensive use of pesticides has led to the need to optimize analytical methodologies for the control of residues in food. The present study aims to compare the efficiency of different ion sources (Eletrospray Ionization-ESI and Atmospheric Pressure Chemical Ionization – APCI) in LC-MS/MS systems, when analysing 22 pesticides in a cabbage matrix. The method performance was evaluated during a validation study. Organophosphates, triazoles, pyrethroids and triazines compounds showed good linearity in the range 0.5–200 μg.Kg⁻¹. Statistical tests were used to evaluate linearity. LOQm values varied from 0.50 to 1.0 μg.Kg⁻¹ to the ESI source, and 1.0–2.0 μg.Kg⁻¹ for the APCI source. Matrix effect was more intense when using the APCI source. Accuracy and precision were evaluated at three levels of concentration (2; 20 and 100 μg Kg⁻¹). Most of the compounds presented recovery between 70 and 120%. ESI-LC-MS/MS system showed greater efficiency in multiresidue analysis in the cabbage matrix.

Leaves of plants from the genus Camellia (CAM) are used to make tea; however, there are limited data that compares chemical composition and biological activity of CAM cultivars used to make six tea types. Fourteen CAM cultivars were analyzed by HPLC and UPLC-Q-TOF-MS/MS and biological activity was assessed in a cell growth assay. Tea bioactives and cell growth inhibition varied 2–4 fold. EGCG was the dominant catechin that predicted the magnitude of growth inhibition. However, pure EGCG did not fully account for inhibitory activity suggesting that it may serve as a chemical marker for bioefficacy. As an unbiased characterization of differences in chemical composition among CAM, individual metabolomes were determined and used to generate principle components (PC). PC’s from the metabolome were complementary to those from targeted analyses of tea bioactives and were predictive of growth inhibition. This study provides a frame work for identifying CAM cultivars with beneficial traits.

In this study, an electrochemical system was established to detect the branched-chain amino acid aminotransferase (BCAT) activity in lactic acid bacteria (LAB). A nanocomposite of chitosan (CS) with multi-walled carbon nanotubes (MWCNTs) was synthesized, and the composite solution were uniformly spread over the glassy carbon electrode (GCE) surface by drop-casting to fabricate an electrochemical biosensor. The composite was characterized by scanning electron microscopy (SEM) and cyclic voltammetry (TEM). Results indicated that the MWCNTs–CS/GCE electrode exhibited higher stability and sensitivity, compared with the GCE electrode. The linear response for nicotinamide adenine dinucleotide (NADH) was 1.0–9.0 μM and the response limit was 0.12 µM. The system effectively and sensitively detected the BCAT activity by NADH concentration in the LAB culture, comparing with the optical method. The culture condition of LAB was optimized by using this system, evidencing that established method was available to detect the BCAT activity of LAB.

The structure and the cation-exchange functional groups of hybrid silica materials were evaluated for the effective detoxification of hydroalcoholic solutions containing eight toxic biogenic amines (BA) usually found in fermented beverages. Results show the effectiveness of the removal is related to the number of amino functions in the extracted molecule, retention by the solid being more effective in the case of multiple amino groups, since retention is stabilized through interaction with the material surface at several points. BA with one amino function (isoamylamine, tyramine, β-phenylethylamine), in general, showed a weak retention by the solids. For BA with more than two amine groups (spermine, spermidine), the removal rate was close to 100% for all studied materials. For histamine, cadaverine and putrescine, the removal percentages were higher with a lamellar structured sulfonic acid functionalized material and with bifunctional materials (SBA-15 type and macroporous) containing sulfonic/phosphonic acid groups obtained by co-condensation sol-gel route.

Heterocyclic aromatic amines (HAAs) are harmful by-products naturally formed during the heating process of foodstuffs. The present work reported an analytical method for HAAs analysis for the first time in bakery products by QuEChERS technique combined with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Bakery products were ultrasonically extracted with acetonitrile and sodium hydroxide solution (1 mmol/L). The obtained extracting solution was nearly dried under nitrogen stream and subsequently purified by QuEChERS technique using primary secondary amine (PSA) as adsorbents. Fourteen HAAs were separated on a C18 column with the mobile phase of a mixture of acetonitrile and 1 mmol/L ammonium acetate water solution (containing 0.04% acetic acid), and detected by MS/MS under multiple reaction monitoring (MRM) mode. The developed method was validated in terms of linearity, matrix effect, accuracy and precision. The method showed a good linearity (R² > 0.999) for all analytes in their corresponding concentration ranges. The method limit of quantifications (LOQs, S/N = 10) of 14 HAAs were in the range of 0.3–4.5 μg/kg. The average recoveries (n = 6) at 3 spiked levels ranged from 62.8 to 96.8% with relative standard deviations (RSDs) of 1.2–7.6%. The validated method was applied in HAAs analysis in 20 bakery products and 4 kinds of HAAs (harman, norharman, AaC, PhIP) were detected with the concentrations ranging from 0.6 to 35.6 μg/kg.

The aim of this study was to evaluate the combination of fatty acid profile and fatty acid δ¹³C fingerprinting to identify the origins of scallops. Fatty acid contents, as well as fatty acid δ¹³C values of 300 samples of three scallop species (Patinopecten yessoensis, Chlamys farreri, and Argopecten irradians) from seven sites in China were determined. Principal component analysis was performed on datasets to evaluate their performance of classification. Moreover, 75 samples were tested by discrimination analysis to estimate the accuracy of origin prediction. The results show that the accuracy rate of fatty acid profile and fatty acid δ¹³C fingerprinting for origin prediction was 92% and 85.3%, respectively. The combination of these two methods improved the identification, with an accuracy rate of 100.0%. These results indicate that the combination of fatty acid profile and fatty acid δ¹³C fingerprinting can be a precise and promising tool for origin traceability of scallops.

The present study evaluated the thermal properties of sponge cake batters with different functional ingredients, and the effects of their adding on starch gelatinization. Samples of sponge cake batter: with wheat flour (control batter), with a reduced quantity of wheat flour and addition of functional ingredients (sponge cake batter with 50% einkorn wholemeal flour, sponge cake batter with 20% Jerusalem artichoke powder, sponge cake batter with 35% cocoa husk powder) were investigated. Using the method of differential scanning calorimetry (DSC) the starch gelatinization temperature intervals (°C) and energies of the different batters during baking were evaluated. Based on the experimental results, it could be concluded that the addition of functional ingredients in the cake batter retard the starch gelatinization. The gelatinization occurs at higher temperature and with higher energy consumption. The retarding effect of the functional ingredients is related to the water binding capacity and the presence of dietary fiber.

The microwave heating of wheat kernels, flour, and gluten, has attracted attention lately because it has been claimed to abolish gluten toxicity for celiac patients. Nevertheless, contradictory results have been reported regarding the effect on gluten celiac-immunotoxicity. In order to better understand the effect of the microwave treatment on gluten structure, conformation, functionality and celiac-immunotoxicity, a central composite design with two factors, power level, and treatment time, was used to investigate a possible quadratic and interaction effects between both factors. Extractable gliadins content was affected by the power and time in a linear and quadratic fashion; extractable glutenins were not affected. Gluten secondary structure was affected by the microwave treatment and related to the polymer’s disaggregation phenomenon observed. In fact, the microwave treatment increased the amount of potentially toxic epitopes released after peptic and tryptic digestion, showing inefficiency as a treatment to detoxify the gluten for celiac disease patients.

Multiwalled carbon nanotubes molybdenum disulfide 3D nanocomposite (MWCNT-MoS₂ NC) was successfully synthesized via eco-friendly hydrothermal method. The microstructural characterization of synthesized nanocomposite was carried out using different spectroscopic and microscopic techniques. Nanocomposite was activated using glutaraldehyde chemistry and used as a platform to immobilize Lens culinaris β-galactosidase (Lsbgal) which resulted in 93% of immobilization efficiency. Attachment of Lsbgal onto nanocomposite was confirmed by AFM, FE-SEM, FTIR, and CLSM. The nanobiocatalyst showed broadening in operational pH and temperature working range. Remarkable increase in thermal stability was observed as compared to soluble enzyme. Nanobiocatalyst showed outstanding increase in storage stability, retained 92% of residual activity over a period of 8 months. This offers good reusability as it retained ∼50% residual activity up to 21 reuses and exhibited higher rate of lactose hydrolysis in whey. MWCNT-MoS₂ NC conjugated to biomolecules can serve as a potential platform for fabrication of lactose biosensor.

To obtain better understanding of the formation mechanisms of bitterness and adhesiveness, protease activities, proteolysis index and protein degradation were investigated among raw, normal and defective hams. Normal and defective hams both showed a decrease in cathepsin B and B + L activities compared with raw ham, while higher residual activities were observed in defective ham. Approximate 1.2-fold values of proteolysis index were observed in defective ham than in normal ham, indicating that cathepsin B and B + L activities were key contributors in degrading muscle proteins of dry-cured ham. 322 proteins were identified by label-free proteomics, and 49 down-regulated proteins were found in the comparison between normal and defective hams. Creatine kinase, myosin, α-actinin and troponin-T showed the most intense response to bitterness and adhesiveness of dry-cured ham, confirmed by partial least squares regression analysis. Myosin could be a suitable biomarker to monitor bitterness and adhesiveness of dry-cured ham.

Different Ohmic heating conditions (OH, 10, 100, and 1000 Hz at 25 V; 45, 60, and 80 V at 60 Hz) were assessed to manufacture whey-raspberry flavored beverages. The inhibition of α-glucosidase, α-amylase, and angiotensin-converting I enzymes, antioxidant capacity, fatty acid profile, and volatile organic compounds (VOCs) were determined. OH treated samples presented lower anthocyanins content than the conventional treatment (2.91 ± 0.23 mg/g), while the mild-intermediate conditions (10,100-Hz at 25 V and 45,60-V at 60 Hz) presented the highest chemical antioxidant activity when compared to the extreme processing conditions (1000 Hz-25 V and 80 V-60 Hz). OH led to an increase of 10% in both α-glucosidase (>99%) and α-amylase (≥70%). Among the VOCs, furfural and 5-hydroxymethylfurfural, a major intermediate Maillard reaction product was found in all treatments. Overall, OH can be used in the processing of whey-flavored raspberry beverages.

In this study, the effects of ultrasonic intensity on conformational changes in aqueous citrus pectin solution under ultrasonic processing and its possible transition mechanism were investigated. The results demonstrated that higher ultrasonic intensity (104.7 W/cm²) caused larger alterations in the molecular and conformational parameters of the semiflexible pectin (Mark–Houwink relation exponent a: 0.820, conformational parameter α: 0.607, structural parameter ρ: 2.22) in aqueous solution. Meanwhile, the semiflexible chain of pectin became more flexible (a: 0.804, α: 0.601, ρ: 1.75) at higher ultrasonic intensity in aqueous solution, as was verified by atomic force microscopy. Moreover, conformational changes in pectin from semiflexible chains to flexible chains or even flexible coils (a: 0.791, α: 0.597, ρ: 1.70) could be attributed to the decreased degree of methoxylation and neutral sugars in side chains and the destruction of inter- and intramolecular hydrogen bonds under ultrasonic processing. Therefore, these results have important implications for understanding the ultrasonic modification of pectin.

To gain a better understanding concerning factors underlying carotenoid metabolism in banana pulp we investigated the carotenoid profile, metabolome, proteome and relative expression levels of carotegenesis-associated genes of fruit pulp in the two banana varieties ON and GN, with ON being characterized of high carotenoid accumulation. Results showed that high carotenoid content in banana pulp was well correlated with the relative expression of carotenogenesis-associated genes and the abundance of the corresponding proteins. An elevated accumulation of sugar metabolism-related compounds and a decreased amino acid accumulation were also observed in ON. Additionally proteins involved in the glycolytic pathway were more highly abundant in ON suggesting that this supports the higher accumulation of carotenoid in this genotype. We suggest that up-regulated expression of carotenogenesis-associated genes alongside elevated carbohydrate accumulation contribute to high carotenoid content in banana pulp, implying that a multi-target approach is necessary in order to improve carotenoid content in banana.

The formation of toxic and potentially carcinogenic acrylamide, alongside volatile aroma compounds, was studied after polyphenols ((+)-catechin, quercetin, gallic, ferulic, caffeic acids) were added to model bread. The addition of as little as 0.1% polyphenols to bread significantly reduced acrylamide (16.2–95.2%). In the case of quercetin, a promoting effect was observed (+9.8%) when its concentration increased. Of all the phenolic compounds, regardless of concentration, ferulic acid showed the highest level of acrylamide inhibition. This is probably due to the presence of 4-vinylguaiacol, a degradation derivative with strong antioxidant activity in heterogeneous systems. Although the phenolic compounds mitigate acrylamide, this adversely affected bread volatile profile. At the highest level (2.0%), caffeic acid most significantly suppressed Maillard-type volatiles (75.9%), followed by gallic acid (74.3%), ferulic acid (65.6%), (+)-catechin (62.4%), and quercetin (59.3%). Among polyphenols, ferulic acid decreased yeast fermentation products level the most (33.1%), simultaneously enhancing lipid oxidation product, probably due to inhibition of amylases and yeast activity.

Use of banana flours as functional ingredients is growing due to their nutritional benefits derived from phenolics and dietary fiber. However, the effect oven-drying, freeze-drying and extrusion on the phenolic compounds or starch digestibility is not understood. In this work, phenolic acids (gallic acid, caffeic acid), flavan-3-ols (epicatechin, catechin) and flavonols (quercetin-3-O-glucoside and myricetin) were quantified in banana flour processed by different methods. Epicatechin, the most abundant phenolic in all flours (up to 1.93 mg/100 g), was significantly reduced during thermal processing (oven-drying and extrusion). Meanwhile, phenolic acids and flavonols were found to be more thermally stable. Thus, oven-drying and extrusion generally improved the extractability of phenolic acids and flavonols. Freeze-drying resulted in native flours with significantly higher insoluble dietary fiber (up to 43.3%), although the digestible starch fraction was digested more rapidly than the oven-dried counterpart.

Muscle foods, particularly fish products are highly exposed to oxidative stress during processing and storage, resulting in oxidative modification of proteins. Protein carbonyls content has been used as one of the measures of oxidative stress. Generally, the resulting carbonylated proteins (CPs) have so far been labeled with 2,4-dinitrophenyl (DNP) hydrazine and detected with anti-DNP antibody. However, the applicability of this method to food samples is limited by its high price, time-consuming procedure and possibility to perform the measurements just on soluble protein fractions. We developed a simpler, faster and cheaper method to assess CP level in muscle foods, including both soluble and insoluble protein fractions, which is based on a direct reaction of protein carbonyls with 7-(diethylamino)coumarin-3-carbohydrazide (CHH). The paper describes a novel technique to label both soluble and insoluble carbonylated proteins with CHH and determine carbonyl content by fluorescence microscopy assay which correlates (R = 0.911) with conventional ELISA method.

To improve the industrial application of wheat bran insoluble dietary fiber (W-IDF), three modification methods (carboxymethylation, complex enzymatic hydrolysis, and ultrafine comminution) were compared on the basis of structural, physicochemical, functional, and antioxidant properties of W-IDF. FT-IR, DSC and SEM analysis showed that modifications contributed to alteration in morphology and arrangement of chemical bonds in W-IDF. Carboxymethylation effectively improved the water retention (WRC), water swelling (WSC), and glucose adsorption capacities (GAC); complex enzymatic hydrolysis greatly improved the oil retention (ORC), GAC, and nitrite ion adsorption capacities (NIAC). Although ultrafine comminution reduced the WRC and ORC, while positively influenced the GAC and NIAC. Moreover, total phenol content, total antioxidant capacity, DPPH radical scavenging capacity, Fe²⁺ chelating capacity and total reducing power were improved in modified W-IDF. Our results confirmed that carboxymethylation can improve the nutritive quality and sensory properties of W-IDF (nutritive ingredient) in food products.

The analysis of free fatty acids (FFAs) in edible oils can provide important information for quality control and oil authentication. Herein, we report the comprehensive profiling of FFAs in edible oils via magnetic dispersive extraction combined with comprehensive two-dimensional gas chromatography-mass spectrometry (GC × GC–MS). A magnetic extractant was designed for dispersive extraction of FFAs. The extraction conditions were carefully optimized. To assess the extraction method, we first use the method for analysis of 7 targeted FFAs. The limits of detection range from 5.6 to 25.8 ng g⁻¹, and the recoveries in oil samples are 81%–107%. We then performed comprehensive profiling of untargeted FFAs in oil by combining the extraction method with GC × GC–MS. A total of 64 FFAs were identified positively or putatively. The proposed method can provide FFA fingerprint data to guide the processing, storage and authentication of edible oils.

The present research was carried out to analyze the effect of chemical composition, granule morphology and crystalline structure of pigmented rice starches on their functional characteristics. The starches of these rice cultivars were observed to possess novel characteristic as compared to hybrids or non-pigmented cultivars in terms of physicochemical, pasting and thermal characteristics. The diameter of the analyzed starch particles depicted a considerable range varying from 5.139 μm to 8.453 μm as their median particle size visualized at ×50. The color values of the analyzed starch samples indicated a high degree of whiteness and purity. The compact nature of starch granules in Kaw quder and Kaw kareed rice cultivars accounted for their higher transition temperatures as compared to other cultivars. Crystalline pattern by X-Ray diffractometer showed an A-type pattern for analyzing starches. The starch granules showed the irregular polyhedral morphology with spherical granules having a polyhedral angular shaped morphology packed tightly with a relatively smooth surface.

Physical, chemical and thermal properties, as well as molecular structure of cassava-based resistant dextrins prepared under different dextrinization conditions (0.04–0.10% HCl, 100–120 °C, 60–180 min) were determined. Increasing acid concentration, temperature and heating time resulted in the products with darker color, higher solubility, reducing sugar content, total dietary fiber and proportion of high molecular weight fiber fraction. An endothermic peak at 45–70 °C, having enthalpy of 1.66–2.14 J/g, was found from the samples processed under mild conditions (0.04–0.08% HCl, 100 °C, 60 min). However, harsher dextrinization conditions eliminated this endotherm. Dextrinization led to 1000-fold decrease in weight-average molecular weight (M_w) of the products, comparing to the native starch. Stronger processing conditions yielded the resistant dextrins with slightly higher M_w but composing of shorter branched chains. During dextrinization, hydrolysis was a predominant step, while transglucosidation and repolymerization played key roles in modifying molecular structure and properties, especially dietary fiber content, of resistant dextrins.

Wheat dough has been considered as a complex blend where gluten forms the continuous reticular skeleton and starch granules act as filling particles. The effect of starch on dough behaviors is not clear and the mechanism of starch affecting dough properties needs to be revealed. In this study, the micro-structure and physiochemical properties of starch from six wheat varieties (lines) with different dough properties were investigated, and the rheological properties of wheat dough were determined. Six varieties with significant different starch properties perform various dough behaviors, among which Xinmai 26 with preeminent dough quality has the highest amylose content, B-type starch granule content, short-range ordered degree and starch swelling power but lowest relative crystallinity and gelatinization enthalpy of starch. The findings indicate that starch physicochemical properties also influence the dough behaviors and provide helpful information for demonstrating the effects of starch on dough properties in the protein-starch matrix.

Retrogradation is inevitable during the storage of starchy products. Retrogradation behavior of starches (e.g., amylopectin and amylose) has been widely investigated. We firstly studied the retrogradation behavior of short linear glucan debranched from amylopectin with different degrees of polymerization (DP). With increasing DP, the retrogradation enthalpy change (ΔH) of debranched starch (DBS) increased. At a DBS to water ratio of 1:2 and a storage time of 0 min, the retrogradation ΔH of DBS samples (DP 11.96, 12.62, and 13.36) reached up to 6.03 ± 0.41, 8.03 ± 0.53, and 12.80 ± 1.57 J/g, respectively. The greater the short-chain length, the more rapid the retrogradation of DBS. The peak temperature of retrograded DBS (101.95–111.53 °C) with a DBS to water ratio of 1:2 stored at 50 °C was greater than that stored at 4 °C. The retrogradation of DBS was rapid, taking only 0–120 min, corresponding to ultra-short-term retrogradation.

Ultrasonic effect on extraction of cyanidin-3-galactoside (Cy3-gal) from pear fruit peel was investigated and compared with conventional extraction (CE) method. Different process factors were tested to determine the optimum conditions for ultrasonic-assisted extraction (UAE). Results revealed that under optimized UAE conditions (ultrasonic power = 162 W, temperature = 71 °C, trifluoroacetic acid = 3%, ethanol = 57%, ultrasonication time = 11 min, and sample to solvent ratio = 1:30 g/ml), Cy3-gal yield was significantly higher (0.34 3± 0.005 mg/g) than from CE (0.266 ± 0.004 mg/g), whereas the extract viscosity during UAE showed a negative impact. UPLC-Triple-TOF/MS analysis detected a total number of 13 anthocyanin compounds, out of which 8 were identified and that mainly consisted of cyanidin, delphinidin and petunidin compounds. Higher yield of Cy3-gal under UAE compared to CE was also justified by higher deformations in the cell structure. The possible mechanism of ultrasonication effect during the extraction process is also proposed in the present study. During scale-up UAE process, the extraction yield of Cy3-gal was recorded higher under batch scale-up compared to continuous operation. The present study is an attempt to optimize UAE of valuable anthocyanins from Pyrus communis ‘Starkrimson’ fruit peel and further scaled-up for higher volume extraction which can be utilized for industrial applications.

An anti-idiotypic nanobody-phage display-mediated immuno-polymerase chain reaction (PD-IPCR) method was developed for simultaneous quantitative detection of total aflatoxins and zearalenone in cereals. Two phages, displaying the variable domain of the heavy chain anti-idiotypic nanobody that binds aflatoxin- or zearalenone-specific monoclonal antibody (1C11 or 2D3), were used as competitors for corresponding analytes. Specific DNA sequences encoding anti-idiotypic nanobodies were used to design the primers for PCR amplification. The results indicated that detection limits for total aflatoxins and zearalenone in a sample were 0.03 and 0.09 ng mL⁻¹, respectively. Recoveries of spiked aflatoxins and zearalenone were 80–118% and 76.7–111%, respectively. Validation results were in good agreement with the gold-standard high-performance liquid chromatography method. This report is the first to describe PD-IPCR for simultaneous quantitative detection of total aflatoxins and zearalenone in cereals.

Rice glutelin (RG) and phosphorylated rice glutelin (PPRG) were treated with heating for different time (15, 30, and 45 min), the effects of phosphorylation modification on the structure, interactions and rheological properties of rice glutelin during heat treatment were investigated. The results showed that the turbidity of PPRG samples were higher than those of RG samples after heating. Particle size distribution showed that the protein aggregates with particle size of 1000–1500 nm were formed after heating for 45 min. Changes in protein structure indicated that the protein unfolded after heating for a short time, and aggregated when heating time extended to 45 min. In addition, the microstructure of PPRG sample became tight when heated for 45 min. Rheological analysis showed that phosphorylation modification and heat treatment improved RG viscoelasticity. These results suggest that phosphorylation modification improves thermal aggregation of RG, which will facilitate the application of RG in food industry.

Milk fat is arguably one of the most complex fats found in nature and varies widely between animal species. Analysis of its digestion products is tremendously challenging, due to the complexity, diversity, and large range of concentrations of triacylglycerols (TAGs) and their digestion products (i.e. diacylglycerols (DAGs), monoacylglycerols (MAGs), and free fatty acids (FFAs)). Therefore, a method combined the solid phase extraction (SPE), high-performance liquid chromatography (HPLC) and multi-dimension mass spectrometry (MDMS) was developed to identify and semi-quantify the TAGs, DAGs and MAGs in milk fat after in vitro digestion. Up to 105, 64, 14 and 30 species of TAGs, DAGs, MAGs, and FFAs were determined with their concentrations of 0.01–22.3, 0.01–39.2, 0.01–47.8, and 0.04–191.0 mg/g fat, respectively, during the in vitro digestion of cow and sheep milk. The validation of the method shows that this method was precise and reliable.

Agaricus blazei, Auricularia fuscosuccinea and Pleurotus albidus mycelia were obtained in solid-state cultivation (SSC), using grains (brown rice, canjica corn and wheat) as raw material. Colonized grain flours were analysed for their nutritional, physical and physico-chemical characteristics and biological activity in vitro. Wheat flour with P. albidus showed higher values for protein (18.34 g/100 g), ergosterol (0.60 mg/g), mycelial biomass (183 mg/g) and total amino acids (58.34 mg/g). Corn flour with A. fuscosuccinea showed the highest total phenolic content (2.38 mg GAE/g), antioxidant activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) (8.90 μmol TEAC/g) and 2,2′-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (16.52 μmol TEAC/g) assay. Wheat flour with P. albidus were more effective at inhibiting of pancreatic lipase (74.5%) and of α-glucosidase (98.2%). In conclusion, grains colonized by macrofungi mycelia through SSC can enrich the nutritional value and the biological activity of the flours, which presents a potential for functional foods.

Complex starch is gaining research attention due to its unique physicochemical and functional properties. In this study, the effects of green tea polyphenols on the properties and digestion of lotus seed starch under high hydrostatic pressure were investigated. The particle size, swelling power, solubility, crystallization, morphology and thermal properties of lotus seed starch were affected by green tea polyphenols. These may be due to the formation of non-inclusive complexes between lotus seed starch and green tea polyphenols. The morphology and green tea polyphenols distribution of the complexes were determined by scanning electron microscopy and confocal laser scanning microscopy. In addition, slow digestion properties of starch were realized under a dynamic in vitro rat stomach-duodenum model and the erosion of granules by amylase gradually decreased by scanning electron microscopy. Furthermore, green tea polyphenols were shown to be able to form V-type inclusion complex with amylose via high hydrostatic pressure.

A study was conducted on the effects occurred in rheological properties of base flour dough by the addition of gluten, glutenin and purified low molecular weight glutenin subunits (LMW-GS) using a 4 g sample Microdoughlab (MDL). Incorporation of these elements brought about a significant increase in the dough strength in the order of LMW-GS < gluten < glutenin. LMW-GS from variety C 306 brought a decrease in the dough development time (DDT; 2.03 min), dough stability (DS; 3 min) and peak energy (EP; 2.90 Wh/kg) values. On the contrary, the effects of LMW-GS extracted from variety PBW 550 were more strong as indicated by an increase in DDT (2.75 min), DS (3.30 min) and EP (4.20 Wh/kg). The alterations in the microstructure of dough by the inclusion of gluten, glutenin and LMW-GS, which lacks resemblance among different samples, were contemplated subjecting it to Scanning Electron Microscopy (SEM).

Interactions among food components during food processing play important role in starch digestibility. The objective of this study was to investigate the effects of heat moisture treatment on the structural, physicochemical, and digestibility properties of starch-soybean peptide complexes. Corn and potato starch mixed with different amounts of soybean peptide were subjected to heat moisture treatment. The addition of soybean peptide increased pasting temperature, while decreased peak viscosity and swelling power in both starch samples under heat moisture treatment. Thermal analysis showed that soybean peptide retarded starch gelatinization, and heat moisture treatment contributed to a more stable crystalline structure. Lower RDS contents and higher RS contents were associated with higher soybean peptide amounts. Potato starch was more sensitive to heat moisture treatment than corn starch. The results will enrich the interaction theory between starch and protein, and will be important for the development of carbohydrate-restricted diet and protein-based functional foods.

Improving the extraction efficiency and stability of red beet compounds has gained the attention of researchers due to their high nutritional and health benefits. In this study, β-cyclodextrin (β-CD) enhanced ultrasound assisted extraction was used for the extraction of red beet extract, and lyophilized extracts were characterized with FTIR and DSC analyses. The samples extracted with aqueous 5% β-CD solutions revealed the highest content of betanin (2.243 ± 0.04 mg) and total phenolic compounds (20.03 ± 1.28 mg GAE/g DW), and the highest DPPH inhibition activity (59.87 ± 4.94%). Additionally, complexation with β-CD significantly enhanced the stability of betanin, phenolic compounds and antiradical activity in the stored beverage and gummy candy models at various pH and temperature conditions during 28 days. In conclusion, β-CD-enhanced ultrasound assisted extraction is a suitable approach to extracting and stabilizing the red beet compounds for application in food, nutraceutical, and medical fields.

The complexation of nanoparticles in extreme alkali treated (pH 10.0, 11.0 and 12.0) soy protein isolate (SPI) with 1-Octacosanol (1-Octa) was investigated. The nanoparticles were compared in complexing with the 1-Octa concerning their characteristics, along with the changes in secondary structure and stability of 1-Octa upon complexation. The nanoparticles did not display obvious changes in size and morphology upon complexation with 1-Octa, except the surface hydrophobicity. The encapsulation efficiency (EE) and loading amount (LA) of the SPI-Octa were first increased and then decreased with an enhanced pH value. The treatment conditions modified some secondary structures, causing greater protein unfolding to expose more hydrophobic clusters. Additionally, the nanocomplex had higher thermal and saline ion stability, the majority of the nanocomplexes were evenly dispersed in the aqueous phase.

Compositional difference in infant formula (IF) tends to influence its functionality and storage behaviour. The aim was to study the composition and physico-chemical properties of different stages of two commercial IF (A and B). Lactose crystallization measured by X-ray diffraction ranged between 2 and 32 % and was observed to decrease with increasing IF stages, which directly correlates with their composition. Scanning electron microscopy confirmed the presence of crystalline lactose which significantly (p < 0.05) increased the powder particle size. On the contrary, a negative correlation was observed between surface fat and lactose crystallization in all samples. Bulk and surface-free fat composition was significantly (p < 0.05) different for all samples. Surface free-fat analysis showed restricted presence (5–10% of surface fat) of unsaturated fatty acids (C18:1 and C18:2) in IF with higher crystalline lactose as opposed to >40% in others, suggesting a possible role of lactose crystallization in preferential migration of triglycerides to particle surface.

The aim of the present study was to evaluate Paralichthys olivaceus parvalbumin (PV) following treatment by laccase (LAC) in the presence of propyl gallate (PG) on the structure and potential allergenicity. The structure of LAC + PG treated PV was analyzed through SDS-PAGE, CD, fluorescence, and allergenicity was analyzed by immunological and cell model. Our results showed that LAC + PG treatment can induce structural changes through PV cross-linking. Western blotting and indirect ELISA analysis revealed the decrease in IgG binding capacity of PV, corresponding with the structural changes. The results of in vitro digestion illustrate that LAC + PG treated PV showed more resistance to gastrointestinal digestion compared to untreated PV. The release rate of β-hexosaminidase and histamine decreased by 35.6% and 66.9%, respectively, with LAC + PG treatment by RBL-2H3 cell assay. Considering the wide utilization of LAC in food industry, our treatment reveals its potential for creation of hypoallergenic fish products under mild reaction conditions.

Polycyclic aromatic hydrocarbons (PAHs) are primarily produced during the incomplete combustion of organic matter. PAHs are suspected endocrine disruptors and possible carcinogenic materials. The major sources of human exposure to PAHs are inhaled fumes and food. The aim of this study was to provide an alternative drying method to mitigate PAH formation in dried red peppers. We prepared dried red pepper samples using air-drying and heat pump-assisted drying methods, and measured the concentrations of four PAHs (PAH4), benzo[a] anthracene (B[a]A), chrysene (CHR), benzo[b]fluoranthene (B[b]F), and benzo[a]pyrene (B[a]P), in the resulting pepper samples. The PAH concentrations ranged from 3.61 to 18.0 µg/kg and from 2.22 to 8.35 µg/kg in the air-dried and heat pump-dried pepper samples, respectively. Overall, the results have shown that dried peppers contain PAH4, that the drying conditions for these contaminants should be optimized for mitigating the PAH formation in dried red peppers.

This study aimed to evaluate the formation of tryptophan derivatives in the kynurenine pathway during wort fermentation using a multi-response kinetic model and an empirical modified logistic model. Saccharomyces cerevisiae NCYC 88 (ale yeast) and S. pastorianus NCYC 203 (lager yeast) were used to understand the effect of fermentation type on tryptophan derivatives. According to the modified logistic model, tryptophan concentration was critical for the maximum production rate of kynurenic acid, a neuroprotective compound. The results indicated that utilization of tryptophan and kynurenic acid formation were faster in wort fermented with S. cerevisiae than with S. pastorianus. The reaction rate constants implied that the kynurenic acid formation stage was minor compared to other enzymatic reactions leading to NAD⁺ synthesis. Multi-response kinetic modeling of kynurenine pathway provided insights into tryptophan derivative formation, which can facilitate improved beer fermentation processing.

Oak honeydew and chestnut honeys often share the same production area in Atlantic landscapes. Consequently these honeys have common physicochemical properties and pollen composition, making their differentiation by routine methods, a difficult task. The increase in the demands of consumers for clear honey labelling, identifying floral make-ups and the substantial health properties of both honey types, make it necessary to improve methods to differentiate the honeys. Statistical multivariate techniques were used to study the differences in the physicochemical composition and pollen spectra between chestnut honey and oak honeydew honey. Palynological analysis, moisture, pH, electrical conductivity, hydroxymethylfurfural, diastase number, colour, phenolic content, minerals and sugars were used for this purpose. The variables that had more weight in the differentiation by principal component analysis were Castanea, Cytisus type, CIELab coordinates (a^* and L), RSA, Mg and trehalose; 97.6% of the honey samples were correctly classified by linear discriminant analysis.

Authentication of ground coffee has become an important issue because of fraudulent activities in the sector. In the current work, sixty-seven Brazilian coffees produced in different geographical origins using organic (ORG, n = 25) and conventional (CONV, n = 42) systems were analyzed for their stable isotope ratios (δ¹³C, δ¹⁸O, δ²H, and δ¹⁵N). Data were analyzed by inferential analysis to compare the factors whereas linear discriminant analysis (LDA), k-nearest neighbors (k-NN), and support vector machines (SVM) were used to classify the coffees based on their origin. ORG and CONV cultivated coffees could not be differentiated according to C stable isotope ratio (δ¹³C; p = 0.204), but ORG coffees presented higher values of the N stable isotope ratio (δ¹⁵N; p = 0.0006). k-NN presented the best classification results for both ORG and CONV coffees (87% and 67%, respectively). SVM correctly classified coffees produced in São Paulo (75% accuracy), while LDA correctly classified 71% of coffees produced in Minas Gerais.

In this study, through in-situ polymerization process, a novel composite of attapulgite/hydrophilic molecularly imprinted monolithic resin (AT/HMIMR) were prepared in pipette tips for extraction trace plant growth regulators in cucumbers. In the preparation procedure, fibrillar attapulgite nanoparticles were embedded to increase extraction capacity, polyethyleneglycol-6000 was employed as a dual-function porogen, that acted as both the structure-directing agent of the HMIMR and the attapulgite dispersant. N-(1-naphthyl) ethylenediamine dihydrochloride was used as a dummy template to accurate quantification on extraction procedures. Experimental parameters of AT/HMIMR for extracting plant growth regulators from cucumbers were optimized, and the results showed that the recoveries of ranged from 92.4% to 101.1% with relative standard deviations ≤ 6.5% (n = 3). Considering its microporous monolithic column structure, multiple adsorption mechanism, and specific selectivity, AT/HMIMR shows promise for applications that require specific recognition for the analytes in real complex samples.

A novel electrochemical sensor was developed combination molecularly imprinted polymers (MIPs) with nanowell technology, and which was utilized for sensitive and selective 17β-estradiol (17β-E₂) detection. A nanowell gold film with a thickness of 120 nm and a pore size of ∼20 nm was immobilized onto gold electrode surface to form a nanowell-based electrode. MIPs was then synthesized onto the nanowell-based electrode using electro-polymerization method, and then the nanowell-based MIP electrochemical sensor was formed. This sensor surface exhibited 3D-nanowell structure with higher surface area and enhanced electron-transport ability, while MIPs afford stronger recognition capability with higher selectivity and specificity. Most importantly, the developed sensor was validated for 17β-E₂ detection in food samples with larger detection range from 1 × 10⁻¹² to 1 × 10⁻⁵ and lower detection limit of 1 × 10⁻¹³. Therefore, such nanowell-based MIP electrochemical sensor may be a promising candidate electrochemical sensor for trace pollution detection in food samples.

Enzyme hydrolysis of corn gluten meal (CGM) is a promising process to prepare oligopeptides with high Fischer ratios (HFOPs). However, the relationship between Fischer ratios and enzyme hydrolysis approaches remains poorly understood. In this study, peptidomes of varying corn protein hydrolysates (CPHs) before and after activated carbon adsorption were profiled and analyzed according to sequence composition and chain length. Fischer ratios of HFOPs depended on sequences in CPHs by differing enzyme hydrolysis approaches, especially branched-chain amino acid (BCAA)-aromatic amino acid (AAA)-containing-oligopeptides. Activated carbon adsorption increased BCAA-containing-oligopeptide contents and decreased oligopeptide contents including AAAs, preferring BCAA-AAA-containing-oligopeptides with long chain length. Employing a three-enzyme hydrolysis approach, HFOPs were obtained with a yield of 49%, comprising 90% of dipeptides and tripeptides and possessing additional bioactivities. This work revealed the mechanism of HFOP production depending on the release and selective removal of oligopeptides and confirmed CGM was a promising alternative for value-added HFOP production.

The wide use of tetracyclines (TCs) for prevention and therapy of animal diseases may result in excessive residues in animal products, which could pose serious risks to human health. A novel molybdenum disulfide nanoplates (MoS₂ NPs)-based fluorescent sensor for tetracycline (TET) is reported. The MoS₂ NPs, synthesized via a facile bottom-up hydrothermal route, showed blue fluorescence at 430 nm in aqueous solution. Interestingly, its fluorescence was quenched significantly upon addition of TET, which is mainly due to a combination of the inner filter effect and electron transfer. Thus, the MoS₂ NPs based fluorescence sensor was delineated for the detection of TET. The methodology here presented showed a low detection limit of 0.032 μM and satisfied recoveries from 88.46% to 108.62% in spiked milk, milk powder and bovine muscle samples.

Choline chloride-based deep eutectic solvents (DESs) were used as green alternatives to conventional organic solvents for extracting valuable flavonoids from citrus peel waste. The effects of viscosity, pH, and polarity of DESs on the extraction efficiency were investigated. Results revealed linear dependence of extraction yield of citrus flavonoids on the polarity of the hydrogen bond donor (HBD). To simultaneously and effectively extract polymethoxylated flavonoids (PMFs) and glycosides of flavonoids (GoFs) with different polarities, five ternary DESs were designed and prepared by combining the effective HBD components. Among the tailor-made DESs studied, choline chloride–levulinic acid–N-methyl urea showed the highest extraction yield of total flavonoids. Under optimized extraction conditions, 18.75 mg/g PMFs and 47.07 mg/g GoFs were extracted from citrus peel with recoveries of 95.87% and 86.32%, respectively. This study presents a useful strategy based on tailor-made DESs to selectively extracted value-added flavonoids from waste peels in the citrus-processing industry.

The possible interactions between α-zein and Ca²⁺ in nixtamalization process were analyzed from a multidisciplinary approach, considering the effect of these interactions on the thermal properties of the nixtamalized flour. SDS-PAGE under reducing and non-reducing conditions did not reveal differences between patterns of zeins from nixtamalized and control samples. However, analysis from affinity capillary electrophoresis indicated an increment in protein volume when calcium is added to zein extracted from nixtamalized flour. In addition, the binding constant for the zein-calcium interaction was calculated indicating a higher affinity for calcium by zein from nixtamalized samples. Molecular dynamics simulations indicated that the interaction α-zein-Ca²⁺ through C-ter was more favorable than Glu48. However, in excess of Ca²⁺ ions, each site could bind one calcium atom at the same time, confirming that aggregation of α-zein through calcium bridges is possible, expanding the technological applications of this protein.

Considering the health risks of E. coli O157:H7 presence in food and water, an affordable and highly sensitive detection method is crucial. Herein, we report the first use of a single antibody-based fluorescent lateral flow immunoassay (FLFIA) depending on non-radiative energy transfer between graphene oxide and quantum dots for determination of E. coli O157:H7 in beef and river water. FLFIA showed a high sensitivity rate thousand-fold better than the conventional lateral flow (LF). In inoculated minced beef and river water samples, the limits of detection were 178 and 133 CFU g⁻¹ or mL⁻¹, respectively. Besides, it presented a high selectivity in the presence of other possible interfering bacteria. The single antibody approach reduced the assay cost to 60% less than the conventional LF. Alongside, the results could be read by portable LF readers or smartphones. These advantages offer FLFIA as a promising technology for pathogen detection in food and water.

Broccoli undergoes yellowing in unfavorable conditions, thereby diminishing the sensory quality and commodity value. This study aimed to investigate systematically cellular and/or biomolecular changes involved in broccoli yellowing by analyzing changes in microstructural integrity, pigment content, and gene expression. On day-5 of storage at 20 °C, the buds turned yellow without blooming and showed structural damage; ultrastructural analysis revealed plastid transformation and abnormal chloroplast development. Genes regulating pigment content and chloroplast structure directly were identified. More specifically, BoCAO and BoNYC1 regulated chlorophyll turnover, affecting chlorophyll a and b contents. Changes in the β-cryptoxanthin content were influenced by the combined action of up- (BoHYD) and downstream (BoZEP) genes. BoZEP and BoVDE were activated after cold-temperature induction. High BoHO1 expression delayed yellowing at low temperature, inducing BoZEP expression. Color intensity correlated significantly with the chlorophyll b, β-cryptoxanthin, and β-carotene contents, which were associated with increased yellowing of plant tissues.

Volatile sulfur-containing compounds (VSCs) often exist at extremely low concentrations, making them difficult to be determined. The VSCs in Laobaigan (LBG) Baijiu were analyzed by headspace solid-phase microextraction (HS–SPME) coupled with GC × GC–SCD, by which 12 VSCs were identified. Among the 65 odor-active compounds that were determined by GC–O with the aid of aroma extract dilution analysis (AEDA), benzenemethanethiol and 2-methyl-3-furanthiol were found to possess the highest FD values of 6561. The limits of detection (LODs) of the identified VSCs determined by GC × GC–SCD were found to be extremely low at 0.05–1.53 ng/L, with their analytical recoveries from 85% to 116%. The VSCs in the LBG samples were determined in a range of concentrations from 0.77 ± 0.02 µg/L to 60.04 ± 2.32 µg/L. Benzenemethanethiol, dimethyl trisulfide, 2-methyl-3-furanthiol and 2-furfurylthiol exhibited odor activity values (OAVs) > 100 and significantly contributed to the overall aroma of LBG Baijiu.

Ferrocene-based nanoporous organic polymer (Fc-NOP) was used as solid-phase extraction (SPE) adsorbent and showed excellent adsorption capacity for chlorophenols (CPs) compared with commercial C18 and multi-walled carbon nanotubes. Then, a SPE method with Fc-NOP packed cartridge combined with HPLC-UV detection was developed to determine CPs in tap water, black tea drinks and peach juice samples. Under optimal conditions, the detection limits of the method measured at the signal to noise ratio of 3 (S/N = 3) were 0.04–0.06 ng mL⁻¹ for tap water and 0.10–0.20 ng mL⁻¹ for black tea drinks and peach juice samples. Satisfactory method recoveries were achieved in the range of 87.6–119% with relative standard deviations of 3.11–7.83%. Result proved that this method was a sensitive and efficient method for determination of trace CPs in foods. The extraction result for more other compounds confirmed that the developed method had a great application potential for analysis of other trace pollutants in food samples.

Rice is the most consumed food worldwide, therefore its designation of origin (PDO) is very useful. Laser-induced breakdown spectroscopy (LIBS) is an interesting analytical technique for PDO certification, since it provides fast multielemental analysis requiring minimal sample treatment. In this work LIBS spectral data from rice analysis were evaluated for PDO certification of Argentine brown rice. Samples from two PDOs were analyzed by LIBS coupled to spark discharge. The selection of spectral data was accomplished by extreme gradient boosting (XGBoost), an algorithm currently used in machine learning, but rarely applied in chemical issues. Emission lines of C, Ca, Fe, Mg and Na were selected, and the best performance of classification were obtained using k-nearest neighbor (k-NN) algorithm. The developed method provided 84% of accuracy, 100% of sensitivity and 78% of specificity in classification of test samples. Furthermore, it is simple, clean and can be easily applied for rice certification.

This study aimed to investigate the effect of hydrogen peroxide (H₂O₂) on membrane lipids metabolism and its relation to pulp breakdown development of longan fruit during postharvest storage. Compared to the control longans, H₂O₂-treated longans showed higher pulp breakdown index, cell membrane permeability, and activities of phospholipase D (PLD), lipase and lipoxygenase (LOX). Moreover, H₂O₂-treated longans maintained higher levels of pulp phosphatidic acid (PA) and saturated fatty acids (SFA). However, H₂O₂-treated longans exhibited lower levels of pulp phosphatidylcholine (PC), phosphatidylinositol (PI) and unsaturated fatty acids (USFA), lower index of unsaturated fatty acids (IUFA), and lower ratio of USFA to SFA (U/S). These findings demonstrated that H₂O₂ caused the increased activities of enzymes involving in membrane lipids degradation and the accelerated decompositions of membrane USFA and phospholipids in longan pulp, which eventually triggered the destruction of the pulp cell membrane structure and the development of pulp breakdown in longans during storage.

The shelf lives of hot-air-dried (HD) and freeze-dried (FD) Penaeus vannamei were predicted by accelerated storage testing combined with Arrhenius Equation. Meanwhile, the changes in lipid profiles and colour of the dried shrimps during storage were investigated. The predicted shelf life of FD shrimp was more than 1.47-fold than that of HD shrimp. Compared to HD shrimp, FD shrimp had lower levels of oxidation parameters such as peroxide value (POV) and thiobarbituric acid-reactive substances value (TBARS) during storage. In addition, FD shrimp had less reduction in lipid components such as triacylglycerol (TAG), phosphatidylcholine (PC), phosphatidylethanolamine (PE) and all fatty acids including saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) after storage. Moreover, FD shrimp showed a less significant decrease in redness value and increase in yellowness value. Therefore, FD shrimps have better quality stability during storage and then possess longer shelf life than HD shrimp.

The objective of this study was to evaluate the effect of the extrusion moisture and temperature on the physical characteristics of breakfast cereals. The chemical composition, microbiological risk and acceptance of the selected breakfast cereal with the best physical quality were assessed to determine the technological viability of the use of these by-products by the food industry. The response surface method and a rotatable central composite design were used, and a desirability test was performed based on adjusted regression models. The breakfast cereal produced under these conditions had protein, lipid and dietary fiber contents of 7.55, 0.97 and 6.12 g 100 g⁻¹, respectively. In regards to the sensory analysis, the evaluated breakfast cereal received average acceptance scores ranging from “neither like or dislike” to “like moderately”. The use of rice, passion fruit and milk by-products was shown to be an alternative for the production of extruded breakfast cereal.

The present study investigated the effects of proteins, lipids and β-glucan in naked oat flour (NOF) on the in vitro digestibility of starch. The content of rapidly digested starch (RDS) increased, and the content of resistant starch (RS) decreased in NOF after removing the non-starch constituents. The estimated glycemic index (eGI) of starch in NOF increased after the removal of the non-starch constituents, with a decreasing order of naked oat starch (NOS) > de-β-glucan flour > de-proteins flour > de-lipids flour > NOF. NOS was found to have an A-type crystalline pattern, but the removal of proteins or β-glucan rendered NOS a V-type crystalline pattern. The relative crystallinity decreased after removing non-starch constituents. The in vitro digestibility was positively correlated with the short-range molecular order and negatively correlated with the relative crystallinity. These results clearly illustrate the effects of non-starch constituents on the low digestibility of naked oat.

Broad molecular weight (MW) distribution and variability of mannan to protein ratio of purified mannoproteins (MP), isolated from yeast cell walls upon the enzymatic treatment, revealed their multiplicity. The main fraction of high-MW Agrimos®-MP1 and YCW-b-MP1′ contained mannoproteins with a mannan to protein ratio of 3.5 and 6.9, respectively. Low-MW YCW-b-MP2′ was mainly comprised of mannan, with a ratio of 181, whereas low-MW Agrimos®-MP2 was characterized by a ratio of 12.2. The solubility of MP1/MP2 was higher than that of MP1′/MP2′. Mannoproteins showed similar or lower solubility than mannan, and they exhibited a Newtonian behaviour. Sonication was the appropriate method for the formation of mannoproteins-based emulsions. Contrary to MP1/MP1′-based emulsions, MP2/MP2′-based ones showed higher affinity towards soybean oil than glyceryl-trioleate. pH affected the emulsifying ability of MP1/MP1′. MP1/MP1′ showed similar or slightly inferior emulsifying properties than lecithin. This study is expected to broaden the applications of mannoproteins as value-added ingredients.

The effect of dietary fiber-rich fractions on the texture, thermal, water distribution, and gluten properties of frozen dough during storage was investigated. These fractions could greatly improve retention of the texture properties, which was mainly related to water loss, and changes in freezable water proportion (FW) and gluten secondary structure. Kinetic studies showed that the fractions could change the nucleation type and ice crystal growth rate, with konjac flour significantly decreasing the ice growth rate from 0.0177 to 0.0048. These fractions could decrease FW by 15%–27% and restrict water mobility during storage. Moreover, gluten β-sheets shifted toward β-turns, while the β-sheet values of potato and okara flours showed no significant change during storage. SEM confirmed that okara flour could suppress the deterioration of gluten. Generally, the potato, okara, and konjac flours represent excellent fortification materials that could improve the texture, reduce water mobility, and suppress deterioration of frozen dough during storage.

Almond shell, a by-product obtained from the nut industry, was valorised into low degree of polymerisation xylooligosaccharides using alkaline pretreatment and enzymatic hydrolysis. The effect of particle size on hemicellulose recovery upon pretreatment was studied using 1 and 2 M NaOH. It was observed that particle size significantly influences hemicellulose recovery, as particles below 120 µm resulted in near complete recovery at 2 M NaOH. Enzymatic hydrolysis of hemicellulose was optimised using response surface methodology, to obtain efficient xylooligosaccharides production at low enzyme dose and high substrate concentration. For higher XOS yield, an enzyme dose of 10 U and substrate concentration <2% was optimal. The in-vitro human faecal fermentation study revealed no significant difference in gas and short chain fatty acid level among substrates evaluated. It was observed that short chain oligosaccharides produce higher level of acetate than medium chain oligosaccharides.