The effect of high hydrostatic pressure (HHP) treatment combined with either of two natural inhibitors, ferulic acid (FA) or epigallocatechin gallate (EGCG) on polyphenol oxidase (PPO) activity and related quality attributes in cloudy apple juice was explored. The results showed that the addition of 0.1 g/100 mL FA or 0.2 g/100 mL EGCG effectively reduced PPO activity in samples, thereby significantly increasing brightness values (P < 0.05). After HHP treatment (550 MPa/5 min), the relative residual activity of PPO was as high as 82.70%, whereas it decreased to 66.35% and 41.50% after HHP + FA and HHP + EGCG treatment, respectively. During 14 days of refrigeration, PPO activity continued to decrease, while color parameters remained stable. On day 14, the HHP + FA group exhibited the lowest brown index (BI) of 4.37, while the HHP + EGCG group had the lowest relative residual PPO activity of 24.71%. Furthermore, both treatments retained more than 80% of the total phenol content and more than 90% of the antioxidant capacity. In conclusion, combined treatment of HHP with FA or EGCG could effectively inhibit the enzymatic browning of cloudy apple juice, demonstrating potential for further promotion and application.

To explore the mechanism by which laser (L) irradiation combined with Spirulina platensis (SP) enhances ferroptosis induced by FeSO4 (Fe) in Salmonella enterica serovar Typhimurium (ST) and Listeria monocytogenes (LM), this study measured lipid peroxidation, reactive oxygen species (ROS), glutathione (GSH), morphological characteristics, cell membrane damage, and expression levels of key genes in the two foodborne pathogens after different treatments. The results showed that the L + SP treatment significantly enhanced the bactericidal effect of FeSO4. The 4 mmol/L Fe + SP + L treatment reduced the counts of both ST and LM to less than 1.4 (lg(CFU/mL)). Additionally, the Fe + SP + L treatment led to increased lipid peroxidation and ROS production and decreased proportion of GSH, thereby damaging the integrity of the cell membrane, increasing the permeability of the cell membrane, decreasing the membrane potential, increasing the leakage of intracellular nucleic acids and proteins, and ultimately resulting in the death of bacteria. In addition, the biofilm inhibition and inactivation experiments showed that the 4 mmol/L Fe + SP + L treatment had an excellent antibiofilm capacity. Finally, the counts of ST and LM on lettuce were significantly decreased to 4.63 and 4.60 (lg(CFU/g)), respectively, after the 4 mmol/L Fe + SP + L treatment. In conclusion, the Fe + SP + L treatment could effectively reduce the counts of ST and LM in both planktonic and biological states, indicating its good potential for controlling foodborne pathogens on the surface of lettuce and other foods.

To prolong the shelf life of fresh beef, we designed and evaluated a preservative (PAW-ε-PLH-nisin) by dissolving ε-polylysine hydrochloride (ε-PLH), nisin, and sodium hexametaphosphate as a water-retaining agent in plasma-activated water (PAW). The effect of the preservative on the quality changes of beef during cold storage was investigated. The results demonstrated that after storage under vacuum at 4 ℃ for 28 days, the total bacterial count of beef treated with the preservative was 5.1 (lg(CFU/g)), within the acceptable limit. The total volatile basic nitrogen (TVB-N) content was 18.3 mg/100 g after 21 days of storage, meeting the criteria for the second freshness grade. The PAW-ε-PLH-nisin treatment notably improved the redness of beef, kept beef texture and sensory characteristics stable during storage, delayed lipid and protein oxidation in beef, and maintained fatty acid stability. These results suggest that PAW-ε-PLH-nisin has significant application potential and high development value in fresh beef preservation.

Sarcoplasmic-calcium-binding protein (SCP) was isolated, purified and identified from Penaeus vannamei. Meanwhile, its physicochemical properties (immunoactivity, thermal stability, pH stability and digestive stability), secondary structures and epitopes were studied. The results showed that the purified protein, which was obtained by successive steps of crude protein extraction, ammonium sulfate fractionation and anion exchange chromatography and exhibited a molecular mass of 21.6 kDa, was identified as SCP with a peptide coverage of 93.26%. SCP had strong immunoactivity, which decreased during heat treatment (≥ 65 ℃) and under strongly acidic and alkaline conditions. SCP had strong stability against intestinal fluid digestion, but poor stability against gastric fluid digestion. The secondary structure of SCP consisted of 26% α-helix, 16.9% β-sheet, 17.5% β-turn, and 39.6% random coil. Eight epitopes in SCP were predicted and identified using bioinformatics tools combined with immunological techniques.

In this study, we systematically investigated the regulatory effects of two hempseed peptides (APAM and RLPA) on pancreatic lipase (PL) and cholesterol esterase (CE) activities and the molecular binding mechanism using enzyme kinetics, synergistic inhibition, fluorescence spectroscopy, isothermal titration calorimetry and molecular docking. The results showed that RLPA had stronger inhibitory activity on PL and CE with half maximal inhibitory concentration (IC50) values of (79.62 ± 3.20) and (301.27 ± 14.40) μmol/L, respectively. Kinetic analysis indicated that the inhibition mechanism of APAM on the two enzymes was competitive inhibition, whereas RLPA was a mixed-type inhibitor. Both APAM and RLPA synergistically inhibited PL and CE with orlistat at low concentrations, but the synergistic effect was weakened or even antagonized at high concentrations. Fluorescence spectroscopy results showed that both peptides could produce static quenching by binding to PL and CE, which changed the hydrophobic environment of aliphatic amino acids in the enzymes. Isothermal titration calorimetry demonstrated that the binding process between the peptides and the enzymes was spontaneous and exothermic, which was achieved mainly through hydrogen bonding and electrostatic interaction. Further analysis using molecular docking simulations showed that hydrogen bonding, salt bridges, and cation-π interactions played crucial roles in peptide-enzyme binding. This study enriches our understanding of the interaction mechanism of peptides with PL and CE, and provides a scientific basis for the development of functional foods based on hempseed protein.

In this study, two low molecular mass fucoidans (LMWFs), F-1 and F-2, derived from Undaria pinnatifida fucoidan, were prepared and purified by free radical oxidation degradation and strong anion exchange chromatography. The chemical composition and structure characteristics of LMWFs were analyzed using molecular exclusion chromatography (MEC), high performance liquid chromatography (HPLC), infrared spectroscopy (IRS) and nuclear magnetic resonance spectroscopy (NMRS), and the structure-antioxidant activity relationship was explored. The results showed that F-1 and F-2 were primarily composed of fucose and galactose, with molecular mass of 2 790 and 23 510 Da, respectively. Their sulfate contents were (27.05 ± 0.95)% and (34.73 ± 0.08)%, and their uronic acid contents were (15.39 ± 0.33)% and (6.76 ± 0.38)%, respectively. In both F-1 and F-2, the configuration of glycosidic bonds was α-type, with a certain degree of acetylation and sulfation. Both LMWFs could scavenge 1,1-diphenyl-2-picrylhydrazyl and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cationic radicals and showed certain reducing power in the potassium ferricyanide reduction assay. These antioxidant properties were concentration dependent. The contents of polyuronide and galactose in the glycan chain of F-1 was relatively high, so its antioxidant activity was superior to that of F-2 under the same dosage conditions. These findings provide a theoretical basis for the application of LMWFs as excellent natural antioxidants in various fields such as health food and cosmetics.

An emulsion gel stabilized by a mixture of whey protein and pectin (WP) and an emulsion gel stabilized by a mixture of whey protein and glucan (WG) were prepared by an acid induction method. The functional properties of WP and WG emulsion gels with dispersed phase volume fractions of 35% and 75% (called WP35, WG35, WP75, and WG75) were evaluated and compared, and the efficiency of high internal phase emulsion gels as a fat replacer in replacing fat in low-fat processed cheese was further investigated. The results showed that WP75 had the smallest mean particle size, uniform fat distribution, and a stable protein network structure. Within the frequency range of 0.1–10 Hz, both the elastic modulus (G’) and viscous modulus (G”) values of the emulsion gel samples tended to increase as the oil phase volume fraction increased. Compared with the other samples, WP75 was superior in terms of deformation resistance, thermal stability, and water-holding capacity. Addition of WP75 into processed cheese with 15% (m/m) fat reduced the oil syneresis and increased the meltability without resulting in significant differences in textural properties compared with the control group (full-fat). This study demonstrated that high internal phase emulsion gels stabilized by whey protein and pectin could be used as a fat replacer in the development of low-fat cheese products.

This study investigated the effects of adding different amounts of flaxseed gum (0%, 0.2%, 0.4%, 0.6% and 0.8%) on the microstructure and physicochemical properties of starch in frozen dough using scanning electron microscopy (SEM), solid-state nuclear magnetic resonance (SSNMR) spectroscopy, X-ray diffraction (XRD), and rapid visco analysis (RVA). The aim was to reveal the potential mechanism underlying the effect of flaxseed gum on the quality improvement of frozen dough from the perspective of changes in starch characteristics of frozen dough. The results showed that after repeated freeze-thaw cycles, the surface of starch particles appeared sunken, the relative crystallinity of starch decreased, the double helix structure of starch molecules was destroyed, and consequently water molecules were more likely to enter starch particles, thus resulting in an increase in peak viscosity and final viscosity. The addition of flaxseed gum inhibited the formation of ice crystals in frozen dough and delayed the unwinding of the double helix structure of starch molecules, and the hydrogen bond interaction between flaxseed gum and starch molecules increased the relative crystallinity of starch (22.2%–23.8%). As a result, the peak viscosity of starch decreased from 2 409.5 mPa⋅s to 2 247.2–2 288.5 mPa⋅s, and the gelatinization temperature gradually increased. In conclusion, flaxseed gum delayed the damage of starch in dough caused by repeated freeze-thaw cycles, thereby protecting frozen dough.

Ternary composite gels consisting of carrageenan, hydroxypropyl distarch phosphate and egg white protein were characterized for gel properties and microstructural characteristics. Meanwhile, the interaction between different modified egg white powders (P10, PHG14 and PHG21) and polysaccharides was investigated, as well as their effects on the properties of composite gels. The results showed that compared with carrageenan and a binary composite gel consisting of carrageenan and modified starch, the ternary composite gel showed an increase in gel strength and water-holding capacity, a significant increase in elastic modulus (G’), a significant reduction in relaxation time T23, a decrease in its relative peak area A23, and a decrease in freezable water content. The infrared spectra of the polysaccharide-protein composite gel showed an increase in amplitude and a slight shift in peak position. X-ray diffractometry revealed that the diffraction peak intensity of the polysaccharide-protein composite gel was weakened, implying a reduction in the degree of crystallinity. Microstructural observation by scanning electron microscopy (SEM) revealed that the interaction between the polysaccharides and egg white proteins facilitated the formation of stable, dense and uniform gel networks. Compared with P10, addition of PHG14 or PHG21 to the carrageenan-modified starch composite gel resulted in more stable gel properties and microstructure.

In order to further investigate the structural properties and catalytic function of acarviosyltransferase (ATase), a key enzyme in the biosynthesis of acarbose, its gene (acbD) was cloned from Actinoplanes sp. SE50 genome and heterologously expressed in Escherichia coli. Bioinformatics analysis showed that the conserved domains of ATase, the expression product of acbD, were highly similar to those of cyclodextrin glycosyltransferase, which belongs to the glycoside hydrolase 13 (GH13) family, and ATase possessed a signal peptide and a transmembrane domain. After removal of the coding sequences in the signal peptide, the soluble expression level of acbD increased by 23.4 times as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimal catalytic temperature and pH for the recombinant ATase were 30 ℃ and 7.0, respectively. The substrate spectrum showed that the recombinant ATase had the highest catalytic activity toward D-salicin (82.85 U/mL), followed by that (63.75 U/mL) toward L-sorbose. This is the first finding that L-sorbose can serve as an excellent glycosyl donor for ATase. The above results lay the foundation for further clarifying the catalytic mechanism of ATase.

This study evaluated the effect of co-fermentation using Streptococcus salivarius subsp. thermophilus CZ-03 and Bifidobacterium animalis subsp. lactis LGG-08 on the quality of fermented milk. Changes in microrheological properties during the fermentation process were studied using multi-frequency diffusing wave spectroscopy, and changes in pH, titratable acidity (TA), viable bacterial count (VBC), exopolysaccharide (EPS) content, viscosity, water-holding capacity (WHC), texture properties, and sensory evaluation were examined as well. The results showed that during the initial storage period (0–14 days), the EPS content of the co-fermented milk increased from 204.7 to 233 mg/L, which was significantly higher than that of the single-strain fermented milk. Additionally, the VBC in the co-fermented milk was significantly higher than that in the single-strain fermented milk throughout the storage period, indicating that the co-fermentation could significantly enhance the storage stability and probiotic functions of the product. The use of co-cultures markedly improved the rheological and texture characteristics of fermented milk, particularly viscosity and WHC. Compared with the single-strain fermented milk, the co-fermented milk was more capable of forming a stable gel structure. These findings provide a solid scientific basis for the development of probiotic fermented milk products and the enhancement of their health benefits and also offer innovative perspectives and strategies for the production and storage characteristics evaluation of fermented milk.

In this study, four esterases (ES1, ES5, ES8 and ES9) with relatively high ethyl carbamate (EC)-hydrolyzing activity at both pH 4.5 and 7.0 were identified from the NCBI database, and their soluble expression in recombinant Escherichia coli was achieved. Then, the expressed enzymes were purified and characterized. The results showed that the optimal temperatures for ES1, ES5, ES8 and ES9 were 70, 70, 55 and 55 ℃, respectively. The optimum pH for ES1, ES5 and ES9 was alkaline, while that for ES8 was neutral. The stability of all four enzymes was significantly reduced at temperature higher than 45 ℃ or pH lower than 5. Their activity was strongly inhibited by Fe3+, Co2+, and Cu2+. In the presence of 10% (V/V) ethanol, ES1, ES5, ES8 and ES9 maintained 50.48%, 48.44%, 42.60%, and 33.59% of their activity, respectively. They maintained 24.09%, 20.41%, 16.11%, and 10.73% of their activity, respectively, at a NaCl concentration of 5%, respectively. Their Michaelis constant (Km) values toward EC at pH 4.5 were 210.7, 213.8, 256.2 and 127.2 mmol/L, respectively, and their catalytic constant/Michaelis constant (kcat/Km) ratios were 214.31, 203.20, 161.46 and 257.43 L/(mol·s), respectively. Structural analysis indicated that the narrow substrate channel of ES9 might affect the entry of EC, thus affecting its maximum reaction rate (Vmax) toward EC; the relatively high affinity of ES9 for EC might be attributed to the strong hydrogen bonding between them. The EC-degrading esterases had good ethanol tolerance, which not only enrich the EC-hydrolyzing enzyme library, but also provide a new method for controlling the EC content in traditional fermented foods with low alcohol content.

In this study, three enzymatic hydrolysis methods, alkaline protease (E1), pepsin + trypsin (E2), and alkaline protease + pepsin + trypsin (E3), were used to prepare hemoglobin hydrolysates from Ningxia beef cattle, which were screened for their antioxidant activity. Amino acid analysis and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were used to identify the amino acid compositions and sequences of the hydrolysates with molecular mass < 3 kDa. The potential antioxidant peptides were selected by computerized analysis and their activities were verified. Their action mechanism was studied by molecular simulation. The results showed that E3 exhibited the highest hydrolysis efficiency, and the < 3 kDa fraction obtained from the ultrafiltration of the resulting hydrolysate showed better antioxidant activity with half maximal inhibitory concentration (IC50) of (18.382 ± 0.023) mg/mL and (0.246 ± 0.012) mg/mL against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cationic radical, respectively. The < 3 kDa fraction was rich in hydrophobic and aromatic amino acids, and four peptides with the best antioxidant activity were selected and identified, whose amino acid sequences were DWGHSW, VFYPW, GTGW and TYFPHF, respectively. Among them, VFYPW showed the highest DPPH radical and ABTS cationic radical scavenging capacity with IC50 of (0.350 ± 0.013) mg/mL and (9.482 ± 0.122) µg/mL, followed by DWGHSW. DWGHSW and VFYPW were found to form stable complexes with Keap1 protein (PDB ID: 2FLU) through hydrogen bonds and hydrophobic interactions. In summary, this study provides a theoretical basis for the application of hemoglobin peptides from Ningxia beef cattle as natural antioxidant supplements and contributes to the high-value utilization of blood resources from Ningxia beef cattle.

Moderate intake of whole grains and non-soy legumes can improve glucose and lipid metabolism, but excessive intake may have an adverse effect. Due to the lack of corresponding conversion relationships, the intake of whole grains and non-soy legumes in mouse feed cannot directly serve as a reference for human intake. This paper introduces the addition levels of common whole grains and non-soy legumes in mouse feed and explores their relationship with the recommended dietary intakes (RDI) of common whole grains and non-soy legumes in humans using various methods, including equivalent coefficient, surface area ratio, body shape coefficient, food density, body surface area index, energy conversion, and nutrient conversion methods. The results indicate that the RDI of 50–150 g of whole grains and non-soy legumes in humans could be equivalently converted into addition of 5%–50% whole grains and beans in the feed of mice with a 3 g daily feed intake. Dietary addition of whole grains and non-soy legumes exceeding 50% might place mice at risk for overconsumption. This study provides an important reference for establishing the conversion relationship between the amounts of whole grains and non-soy legumes added to mouse feed and the RDI of whole grains and non-soy legumes in humans.

To investigate the hepatoprotective components and mechanism of Agaricus bisporus ethanol extract (ABEE), ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used to analyze and identify the components of ABEE. The active components and mechanism were analyzed using network pharmacology and a mouse model of CCl4-induced acute liver injury. UPLC-MS/MS analysis identified 75 compounds, of which 15 were predicted by network pharmacology to be related to liver injury, with 11 different targets. Animal experiments showed that ABEE significantly alleviated CCl4-induced acute liver injury in mice. Compared with the model group, the high-dose group (1 000 mg/kg) showed significant recovery in liver function indicators such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (AKP) (P < 0.001). The antioxidant capacity in mice was significantly enhanced, as evidenced by a significant increase in superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities (P < 0.001) and a significant decrease in malondialdehyde (MDA) content (P < 0.01). Detection of the mRNA and protein expression levels of relevant genes was performed using real-time quantitative polymerase chain reaction (PCR) and Western blot techniques, showing that compared with the model group, the expression of the Bcl-2 in the high-dose group significantly increased (P < 0.001), while the expression of MYC, NF-κB1, RELA and MMP9 significantly decreased (P < 0.01). These results confirmed the predictions, indicating that ABEE might exert its hepatoprotective effect by regulating the expression of Bcl-2, MYC, NF-κB1 and RELA through salicylic acid, palmitic acid, linolenic acid, and chrysin, as well as their associated signaling pathways such as chemical carcinogenesis-receptor activation. This study suggests that ABEE may provide liver protection by inhibiting apoptosis, carcinogenesis, and lipid peroxidation caused by free radicals through multiple components, targets, and pathways.

High performance liquid chromatography (HPLC) and headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) were employed to analyze the changes in volatile metabolites in wild-type Ailsa Craig tomato fruits in four ripening stages (mature green, breaker, light ripe and red ripe) at the metabolic and transcriptional levels. The results showed that the contents of citric acid, lycopene and β-carotene in tomato fruits increased with fruit ripening, while the contents of malic acid and β-cryptoxanthin decreased. Our analysis identified 81 volatile components across the four stages, the total amount of these compounds being in the decreasing order of red ripe > light ripe > breaker > mature green. Correlation analysis between 40 differential metabolites and quality indicators indicated that lycopene was positively correlated with the volatile metabolite 6-methyl-5-hepten-2-one. Furthermore, the expression of chlorophyll degradation-related gene (SlSGR1) and carotenoid synthesis-related gene (SlPSY1) reached their highest levels in the breaker stage, mirroring the trend observed for trans-2-hexenal. The expression of carotenoid synthesis-related genes (SlLCYb and SlBCH2) peaked in the red ripe stage, mirroring the trend of 6-methyl-5-hepten-2-one. We hypothesized that the regulation of genes related to carotenoid metabolism during ripening period may alter the flavor of tomato fruits. This study will contribute to a comprehensive understanding of the intrinsic mechanisms underlying tomato fruit ripening, and provide a new theoretical basis for the metabolic regulation of flavor during fruit ripening and the improvement of fruit quality.

In order to investigate the contents and distribution patterns of saccharides and amino acids in five types of honey from Yunnan province, Macadamia integrifolia honey, Coffea honey, Leucosceptrum canum Smith honey, Vicia villosa Roth honey, and Hevea brasiliensis honey, the contents of 12 saccharides and 20 amino acids in them were determined, and hierarchical cluster analysis (HCA) and partial least squares-discriminant analysis (PLS-DA) were used to explore the applicability of saccharide and amino acid contents to their classification and discrimination. The results showed that the contents of fructose, glucose and sucrose in the five types of honey met the requirements of the industry standards. The total amount of 10 oligosaccharides ranged from 5.35% to 7.92%, with a significant correlation being observed between turanose and mlatulose, kojibiose and isomaltose. The total amount of 20 amino acids ranged from 312.54 to 1 245.51 mg/kg, in the decreasing order of Coffea honey > L. canum Smith honey > V. villosa Roth honey > H. brasiliensis honey > M. integrifolia honey. Significant differences in amino acid composition and content were found among honey types, and Coffea honey contained more than 10 times as much tyrosine as all other types, from which it was inferred that tyrosine could be a potential marker of Coffea honey. The results of cluster analysis showed good classification of the five types of honey according to amino acids with an accuracy of 98.5%. PLS-DA could also distinguish them effectively, and six differential amino acids, proline, arginine, tryptophan, histidine, asparagine and alanine, were selected using the cutoff of variable importance in projection (VIP) value > 1, which could be used to classify the five types of honey in Yunnan.

The differences in the quality and antioxidant activity of Thompson seedless raisins from nine production areas in Turpan were analyzed. Their phenolic composition and content were determined by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The results showed that raisins produced in Lianmuqin had the largest mean single unit mass and shape index of 0.81 g and 2.74, respectively, while raisins produced in Gaochang had the smallest values of 0.46 g and 2.27, respectively. Raisins produced in Yuanyichang had the highest solid/acid ratio of 29.34, while raisins produced in Qiketai had the lowest value of 25.74. Lianmuqin raisins had the lowest a* value of 2.56 and a ΔE value (44.94) below the medium level, indicating the greenest color. The a* value of Yuanyichang raisins was below the medium level (2.94) and its ΔE value (44.19) was the lowest. The color of raisins from these two areas tended to be green and the most consistent with each other. A total of 518 monomeric phenolics were identified in Thompson seedless raisins from the six production areas, including 275 flavonoids (53.09%), 136 phenolic acids (26.25%), 60 lignans and coumarins (11.58%), 19 tannin (3.67%) and 28 others (5.41%). A total of 246 differential metabolites were identified in raisins from Lukeqin versus Gaochangqu (124), Qiketai versus Shengjinxiang (144), and Yuanyichang versus Lianmuqin (66), with 54, 92 and 22 differential metabolites being unique to these comparisons, respectively and 10 differential metabolites being common to all of them. The above results indicate that Lianmuqin and Yuanyichang can be considered as advantageous production areas for Thompson seedless raisins.

In this study, the solid-state fermentation process of Shanxi aged vinegar was investigated. Samples of fermented grains (Cupei) taken at different spatial locations and at different fermentation times were analyzed for physicochemical characteristics, flavor substances and microbial community composition by metagenomics and headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). The results showed that the moisture and temperature of Cupei significantly varied among spatial locations. A total of 93 volatile flavor compounds were detected during the fermentation process, and the total content of volatile compounds decreased in the order of upper layer > middle layer > lower layer. The total acid contents in the upper, middle, and lower layers were significantly negatively correlated with Proteus, Salicicolus, Staphylococcus, and Klebsiella (P < 0.05), affecting microbial growth and metabolism. The water content of the lower layer significantly affected the growth and metabolism of Proteus, Salicicolus, Saccharomyces, Staphylococcus, and Klebsiella (P < 0.05). Proteus, Saccharomyces, Staphylococcus, and Klebsiella were closely related to physicochemical indicators during the fermentation process. The growth and metabolism of Proteus, Salicicolus, Saccharomyces, Staphylococcus, and Klebsiella in the upper layer of Cupei promoted the production of esters such as ethyl linoleate and ethyl oleate, while the fermentation conditions in the middle and lower layers inhibited the production of some esters. This study helps us to comprehensively understand the brewing mechanism of Shanxi aged vinegar.

In this study, the tender shoots of ‘Jinmudan’ tea plants harvested in summer and autumn were processed separately into green tea, yellow tea, white tea, oolong tea and black tea. Headspace-solid phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) was used to determine and analyze the volatile metabolites in the 10 tea samples. The results showed that 522 volatile metabolites were identified in the summer tea, mainly including terpenes, esters and alcohols, and 502 volatile metabolites in the autumn tea, mainly including terpenes, esters and heterocyclic compounds. The analysis of odor activity value (OAV) showed that β-ionone, α-ionone, decanal, methyl benzoate and geraniol were the key aroma substances of Jinmudan green tea; β-ionone, 2-ethoxy-3-methylpyrazine, decanal, methyl benzoate and geraniol were the key aroma substances of Jinmudan yellow tea; geraniol, phenylacetaldehyde, methyl salicylate (E)-linalool oxide, and 2-ethoxy-3-methylpyrazine were the key aroma substances of Jinmudan white tea; indole, methyl benzoate, phenylacetaldehyde, geraniol, and (E)-linalool oxide were the key aroma substances of Jinmudan oolong tea; geraniol, linalool, phenylacetaldehyde, methyl benzoate, and methyl salicylate were the key aroma substances of Jinmudan black tea. The contribution, type and quantity of aroma substances in the autumn tea were greater than those in the summer tea. The OAV of 42 key aroma substances such as geraniol, methyl salicylate and phenylethanol in the autumn tea samples were higher than those in the summer tea samples. Overall, flowery aroma was the major aroma type of Jinmudan tea, and the aroma quality of the autumn tea was better than that of the summer tea. Totally 14 volatile metabolites such as geraniol, linalool, 2-ethoxy-3-methylpyrazine and methyl benzoate were the key aroma substances of the ‘Jinmudan’ tea variety.

This study investigated the effects of different cooking methods and durations on the contents and activities of bioactive compounds in shiitake mushroom digested in vitro in simulated gastrointestinal juices. The contents of total phenols, total flavonoids, crude polysaccharide and eritadenine in steamed, boiled, air fried, or roasted mushroom digested in vitro in simulated gastrointestinal juices were determined, as well as their in vitro antioxidant, hypolipidemic and hypoglycemic activities. Furthermore, the correlation between the contents of bioactive compounds and the in vitro activities of the digests was analyzed. The results showed that compared with steaming, boiling, and air frying, roasting was more conducive to the retention of the four bioactive substances in shiitake mushroom. The contents of total phenols, total flavonoids and crude polysaccharides in the sample roasted for 5 minutes and the content of eritadenine in the sample roasted for 15 minutes were the highest, which were (222.13 ± 3.57) mg/g, (4.49 ± 0.06) mg/g, (5.57 ± 0.28) g/100 g and (551.31 ± 3.76) mg/100 g, respectively. After in vitro gastrointestinal digestion, the release of bioactive compounds from roasted mushroom was the highest, followed by air fried mushroom. The release of total flavonoids decreased with roasting time, while the release of all other bioactive substances had no significant correlation with cooking time. The in vitro activity of the simulated intestinal digest of steamed mushroom was the highest. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity of the in vitro intestinal digest of shiitake mushroom steamed for 20 minutes and the 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation scavenging capacity of the in vitro intestinal digest of shiitake mushroom steamed for 10 minutes were the highest (P < 0.05), which were (88.74 ± 0.34)% and (50.39 ± 0.07)%, respectively. However, there was no significant difference (P > 0.05) in the α-glucosidase inhibitory activity of the intestinal digests of shiitake mushroom cooked by different methods. The highest pancreatic lipase inhibitory activity of (49.42 ± 2.32)% was found in the intestinal digest of shiitake mushroom steamed for 10 minutes (P > 0.05). The results of correlation analysis showed that the α-glucosidase inhibitory activity of the gastric digest was significantly positively correlated with the contents of total phenols (P < 0.01) and eritadenine (P < 0.05), while the ABTS radical cation scavenging capacity was significantly positively correlated with the contents of total phenols (P < 0.05) and crude polysaccharides (P < 0.01). The pancreatic lipase inhibitory activity of the intestinal digest was significantly negatively correlated with the contents of all four bioactive substances (P < 0.01). In summary, roasting was more conducive to the retention and digestive release of bioactive substances, while steaming was more conducive to improving the in vitro activity of simulated digested shiitake mushroom. This study provides guidance for the scientific and rational processing of shiitake mushroom.

In order to investigate the effects of different reheating methods (microwave, steam, water bath, and open flame) on the quality of quick-frozen prepared pork rib soup with carrot and corn, heating characteristics, texture, soup color, taste substances, volatile components, and sensory quality were determined. The results demonstrated that microwave reheating was the most efficient, providing uniform heating. In terms of texture, microwave and water bath reheating had less effects on the hardness, stickiness, and meat firmness of pork ribs, while microwave and open-flame reheating maintained the hardness and stickiness of corn and carrot significantly better (P < 0.05). The steam reheated soup was golden and clear in color, whereas the open-flame reheat soup became thick and milky white due to oil emulsification. The steam reheated soup exhibited a good combination of umami amino acids and nucleotides, presenting the strongest umami taste with an equivalent umami concentration (EUC) of 178.4 g/100 g, followed by those reheated by microwave, open flame, and water bath (EUC of 109.9, 100.2, and 56.5 g/100 g, respectively). A total of 61 volatile components were identified across all samples. In total, 29, 33 and 32 volatile components were found in the microwave, steam and open-flame reheated samples, respectively, with aromatic substances being the major ones; 31 volatile components in the water bath reheated sample, alcohols being the major ones. There were significant differences in the contents of some volatile components (P < 0.05). Sensory evaluation showed that the microwave and steam reheated soups were more favored by consumers in terms of color and taste (P < 0.05), with the highest overall sensory score. In summary, steam and microwave reheating are ideal reheating methods for frozen pork rib soup with carrot and corn.

In order to explore the effects of different cultivation modes (hydroponics, soil culture and substrate culture) on the postharvest quality and flavor substances of Chinese leek during storage, ‘Hangyan 791’ Chinese leek grown in hydroponics, soil culture or substrate culture were stored at 20 ℃ and relative humidity of 80%–85% after harvest and evaluated for changes in physiological quality and flavor substances. The results showed that soil culture and substrate culture better maintained the mass loss rate and decay rate of Chinese leek during storage, while hydroponics resulted in higher mass loss rate and decay rate. Compared with hydroponics, soil culture and substrate culture better maintained vitamin C (VC) and soluble protein contents, and resulted in higher dietary fiber content. Soil culture promoted the accumulation of cellulose, hemicellulose, pectin and lignin. Substrate culture resulted in a downward trend in lignin content. The cellulose content of the hydroponic leek showed a downward trend during storage, while the lignin content was basically unchanged. The main flavor substances of Chinese leek were aldehydes, alcohols, esters, ethers and heterocyclic compounds, among which α-terpineol, isoamyl butyrate, methyl salicylate and phenylacetaldehyde were common to the three samples, both before and after storage. The quality and flavor substances of the soil cultured leek were better maintained during storage, which had the strongest storability, and its quality deterioration was dominated by aging, followed by substrate culture. The hydroponic leek had the worst storability, with softening and rotting being the major signs of quality deterioration.

Considering insufficient sample numbers in the practical detection of soluble solid content (SSC) in cherry tomato, we proposed a deep convolutional generation adversarial network (DCGAN) model to expand spectral data and SSC label data, and established a one-dimensional convolutional neural network regression (1D-CNNR) model to improve the prediction accuracy and generalization capability of the DCGAN model. For comparison, a partial least squares regression (PLSR) model and a support vector regression (SVR) model were established. The original dataset of 80 samples, the DCGAN extended dataset of 1 000 samples and the combined dataset of 1 080 samples were separately used for modeling and prediction with 1D-CNNR, SVR and PLSR. To further verify the generalization capability of the models, a new batch of 40 cherry tomato samples was used as a new test set. The results showed that the 1D-CNNR model based on the calibration set separated from the combined dataset was the optimal regression model for SSC detection. The prediction accuracy of the model for the test set from the combined dataset was the highest, with correlation coefficient of prediction (rp) of 0.980 7, and root mean square error of prediction (RMSEp) of 0.192 9. The prediction accuracy of the 1D-CNNR model for the new test set of 40 samples was also the highest, with rp of 0.963 8 and RMSEp of 0.224 5. This study provides a new idea for the accurate determination of the SSC in cherry tomato.

A nano-immunosensor for the rapid determination of 3-amino-5-methylmorpholino-2-oxazolidinone (AMOZ) in aquatic products was prepared by immobilizing anti-AMOZ antibodies onto a glass carbon electrode modified with a hybrid nanocomposite (Fe3O4@AuNPs/MWCNTs-COOH) consisting of magnetic ferric oxide (Fe3O4), gold nanoparticles (AuNPs), and carboxylated multi-walled carbon nanotubes (MWCNTs-COOH). The microstructure of the prepared nanoparticles of Fe3O4 and Fe3O4@AuNPs was analyzed using ultraviolet-visible (UV-vis) spectroscopy and infrared (IR) spectroscopy, and their microscopic morphology was characterized using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrochemical performance of the prepared immunosensor was studied by cyclic voltammetry, electrochemical impedance spectroscopy, and the experimental conditions were optimized by differential pulse voltammetry using [Fe(CN)6]3-/4- as the probe. The optimized conditions were as follows: V(Fe3O4@AuNPs) to V(MWCNTs-COOH) ratio 1:2, electrolyte solution pH 7.0, antibody concentration 80 μg/mL, incubation temperature 37 ℃, and incubation time 30 minutes. Under these conditions, the current response of the immunosensor showed a good linear relationship with lg C[AMOZ] in the range from 1.0 × 10-10 to 8.0 × 10-7 mol/L, with a detection limit of 2.4 × 10-11 mol/L. The recovery rates of spiked crucian carp samples were between 92.78% and 102.61%, which was basically consistent with the results of high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Furthermore, the immunosensor method has the advantages of simple pre-treatment and fast detection speed, and can be used for the rapid detection of AMOZ in actual aquatic products.

To effectively assess food safety risks associated with potential plant toxin residues present in honey, this study aimed to establish and validate a method for the detection of 39 plant toxins in honey using solid-phase extraction combined with ultra-high performance liquid chromatography-tandem mass spectrometry (SPE-UPLC-MS/MS). The developed method involved sample extraction with 0.1% formic acid, purification using a hydrophilic-lipophilic balanced (HLB) cartridge, detection in the multiple reaction monitoring (MRM) mode, and quantification using the matrix-matched external standard method. The calibration curves exhibited good linearity for all the analytes. Average recoveries ranged from 78.7% to 112.8% with relative standard deviation (RSD) between 1.6% and 15.2% (n = 6). This method was characterized by ease of operation, high throughput and high sensitivity, and could be used for the monitoring these toxins in honey. Varying levels of pyrrolizidine alkaloids (PAs) and rhodojaponin III were detected in some of the 36 tested batches of honey, confirming the presence of phytotoxin residue risks in honey.

A QuEChERS combined with high performance liquid chromatography (HPLC) method was developed for the rapid determination of natural capsaicin, dihydrocapsaicin and synthetic capsaicin in hot pepper and its products. The samples were extracted with acetonitrile and purified by sequential use of anhydrous magnesium sulfate, octadecylsilane (C18), ethylenediamine-N-propylsilane silica gel (PSA) and graphitized carbon black (GCB). An Agilent Eclipse Plus C18 column (150 mm × 4.6 mm, 5 μm) was used for separation, gradient elution was performed with a mobile phase comprising 0.4% phosphoric acid aqueous solution and 90% acetonitrile in water, and a fluorescence detector was used for detection. The results showed that natural capsaicin, dihydrocapsaicin and synthetic capsaicin had a good linear relationship in the range of 0.20–100 mg/L, with determination coefficients (R2) greater than 0.999. The limits of detection (LOD) and quantification (LOQ) of natural capsaicin were 0.014–0.069 mg/kg and 0.046–0.23 mg/kg, respectively. The LOD and LOQ of dihydrocapsaicin were 0.023–0.12 mg/kg and 0.077–0.39 mg/kg, respectively. The LOD and LOQ of synthetic capsaicin were 0.018–0.088 mg/kg and 0.059–0.30 mg/kg, respectively. The recovery rates were 91.6%–117.2% and the relative standard deviation (RSD) were 0.2%–6.1% for dry hot pepper, fresh hot pepper, shiitake mushroom paste with hot pepper and chili oil at three different spiked levels. The developed method is simple, accurate and suitable for the determination of not only dried and fresh hot peppers, but also natural capsaicin, dihydrocapsaicin and synthetic capsaicin in high oil and high protein hot pepper products.

Vanillin is one of the most in-demand spices in the world, which is widely used in various industries such as food, medicinal, and chemical industries. The process of extracting natural vanillin from plants is cumbersome with a limited yield. The chemical synthesis of vanillin faces several issues such as insufficient quality and safety. Microbial transformation is safe and efficient, making it suitable for large-scale production of vanillin. In recent years, due to energy shortages, resource scarcity, and environmental pollution, there has been a rapid development in the production of vanillin by the biotransformation of low-cost, widely available, and renewable agri-food lignocellulosic biomass waste as substrates. This article introduces the types and sources of commercial vanillin, the biotransformation pathway of lignin into vanillin by a process termed biological funneling, and the biosynthesis pathway of vanillin using lignin-derived compounds and glucose as fermentation substrates. It reviews recent progress on the microbial transformation of agri-food lignocellulosic biomass waste into vanillin from three perspectives: strain screening, optimization of cultivation conditions, and metabolic engineering to enhance vanillin production. Moreover, the challenges and potential solutions for current research are discussed. This article will provide valuable guidance for the production of vanillin through the biotransformation of agri-food lignocellulosic biomass waste.

As global aging intensifies, the incidence of age-related bone metabolic disorders, such as osteoporosis, continues to climb. Seeking safe and effective therapeutic interventions is of utmost importance. The modulation of bone metabolism by the gut microbiota and their metabolites has emerged as a focal area of research. Short-chain fatty acids (SCFAs), including acetic, propionic, and butyric acids, exert regulatory effects on bone formation and resorption through the gut-bone axis. Furthermore, SCFAs play positive roles in maintaining bone homeostasis and contribute to the alleviation of inflammatory bone loss. This review synthesizes the current knowledge about the mechanism by which SCFAs regulate bone metabolic homeostasis via endocrine pathways, immune modulation, and enhanced nutrient absorption, hoping to provide a scientific foundation for the prevention and treatment of metabolic bone diseases in the elderly.

Red raspberry is a fruit tree of the Rubus genus in the Rosaceae family. The fruits, leaves, seeds and other parts of red raspberry are rich in polysaccharides, flavonoids, phenolic compounds and other bioactive substances, which have many beneficial health effects such as improving immunity, preventing cardiovascular diseases, and inhibiting the growth of cancer cells. Red raspberry is reputed as a ‘golden fruit’ with commercial application value and drug research value. This paper comprehensively reviews the nutrient composition and content of red raspberry as a function of variety, harvest time and part, and it systematically summarizes health benefits of different parts of red raspberry such as antioxidant, anti-inflammatory, antibacterial, anti-cancer, and metabolic syndrome-alleviating functions as well as their mechanisms of action and application. This review seeks to contribute to a better understanding of the health benefits of red raspberry and to its high-value utilization and deep processing.

Soymilk, as a nutritious plant-based protein drink, is favored by consumers worldwide. However, its undesirable flavor often affects consumer acceptance and limits the marketing of soymilk products. In this review, we summarize recent advances in understanding the formation mechanism of flavor substances in soymilk and their interaction mechanism with proteins in soymilk, and recent progress in improving the flavor of soymilk while maintaining its nutritional value through biological methods such as developing lipoxygenase-free soybean varieties, enzymatic treatment, and microbial fermentation. Finally, we point out future research directions for improving the flavor of soymilk, with a view to providing a theoretical basis for the quality improvement and marketing of soymilk and its products and contributing to the development of the soybean product market in China.

The labeling management of genetically modified foods (GMF) is a crucial link in ensuring food safety. The EU’s prudential supervision of the mandatory labeling of GMF provides a new path option for controlling safety risks. Continuously expanding the scope of GMF labeling, reducing labeling risk thresholds, establishing a whole-process traceability and genetically modified ingredient testing system, continuously optimizing the labeling system for GMF, and building a sound legal system concerning GMF labeling are the mandatory characteristics of EU GMF safety supervision. By reviewing the historical evolution of the EU GMF compulsory labeling system, we herein summarize its major legislative contents and the salient features of the related legal system, and put forward three legislative suggestions for improving the GMF labeling system in China. Furthermore, we propose that supporting measures should be established for traceability, testing and punitive relief. Our aim is to provide innovative ideas for solving the problems existing in China’s GMF labeling system.

Satiety, defined as the state of satisfaction and the end of desire to eat after a meal, is of great significance in maintaining normal appetite, regulating body mass, preventing obesity, and improving metabolic diseases. This article systematically analyzes various factors influencing satiety, encompassing food composition, sensory attributes, energy density, psychological factors, and dietary behaviors. It further elucidates the mechanisms by which these factors contribute to satiety. Additionally, the focus of this article is on introducing the application of emerging technologies in satiety assessment such as the visual analog scale, gastrointestinal hormone measurements, and scintillation scanning, which demonstrate scientific rigor and effectiveness in evaluating satiety. The present article discusses the significance of research on satiety and testing techniques and points out future prospects. Ultimately, it aims to provide theoretical underpinnings and practical guidance for in-depth exploration of the satiety mechanism, innovation in satiety testing techniques, and the development of high-satiety food products.

Milk fat globules (MFGs) originate from mammary epithelial cells, with the lipids and proteins in the milk fat globule membrane (MFGM) maintaining the stability of MFGs through electrostatic repulsion and steric hindrance. Components of the membrane possess specific nutritional properties. Reconstruction of the fat globule interface is critical to the quality of liquid dairy products. Hence, this article critically summarizes and uncovers commonalities among recent studies on the mechanism of milk fat globule interface construction during milk processing. Homogenization disrupts the structure of the MFGM, leading to its rearrangement. Additionally, thermal treatment alters protein structure and induces the lateral separation of lipid domains in the membrane. Meanwhile, the thermal response of proteins and lipids in the MFGM leads to the loss of its components. Exogenous additives participate in the reconstruction of the MFGM by improving the oil-water interface and enhancing the stability of MFGs. Future studies should focus on the connection between the mechanism of MFGM construction and the macroscopic system, as well as optimizing specific processing conditions to obtain higher-quality dairy products.

The intestinal barrier plays a crucial role in maintaining homeostasis in the body. When the intestinal mucosa is damaged, the tight junctions between intestinal cells are disrupted, and the intestinal flora becomes imbalanced, a variety of diseases can arise. Natural active proteins are pivotal in the repair of the intestinal barrier. Lactoferrin, a glycoprotein abundant in mammalian milk, exhibits a range of biological functions such as antioxidant, anti-inflammatory and antibacterial functions. Numerous studies have shown that lactoferrin elevates the levels of intestinal tight junction proteins, promotes the growth and development of intestinal cells, down-regulates the expression of inflammatory factors, regulates the immune response and intestinal microbial diversity, and contributes to the maintenance of intestinal barrier homeostasis. In this paper, a review on the alleviation of intestinal barrier dysfunction by lactoferrin is conducted, aiming to gain a better understanding of the mechanisms underlying lactoferrin’s role in alleviating intestinal injury and to provide insights for the development of lactoferrin-based interventions in intestinal diseases.