The objective of this study was to investigate the effect of dietary supplementation with Clostridium butyricum on the fatty acid metabolism and meat quality of small-tailed Han sheep. A total of 24 three-month-old small-tailed Han sheep in good body condition and with body mass of (28.85 ± 2.01) kg were selected and randomly divided into two groups: the control group was fed a basal diet (a typical corn-soybean diet), and the Clostridium butyricum group was fed the basal diet supplemented with Clostridium butyricum with a viable count of 5 × 108 CFU/g at a dose of 5 g/d. The feeding period lasted for 90 days. After slaughter, rumen fluid was collected for metagenomic analysis, and Longissimus dorsi muscle was harvested to determine its eating quality, fatty acid composition, and gene expression associated with fatty acid metabolism by gas chromatography (GC) and real-time fluorescent quantitative polymerase chain reaction (qPCR). The results showed that feeding Clostridium butyricum significantly improved the brightness value (L*), redness value (a*), pH24 h, and intramuscular fat content (P < 0.05), and reduced the shear force of lamb meat (P < 0.05). In addition, the relative contents of palmitic acid and stearic acid were significantly lower (P < 0.05) and the relative contents of oleic acid, α-linolenic acid, eicosapentaenoic acid were significantly higher in Longissimus dorsi from the Clostridium butyricum group than the control group (P < 0.05). qPCR results showed that dietary supplementation with Clostridium butyricum significantly increased the gene expression of sterol regulatory element binding protein 1C (SREBP-1C), stearoyl-CoA desaturase (SCD), peroxisome proliferator-activated receptor gamma (PPARγ), and acetyl-CoA carboxylase (ACC) (P < 0.05). Metagenomic analysis showed that dietary supplementation with Clostridium butyricum increased the abundance of Firmicutes, Clostridium, and Fibrobacters (P < 0.05), and significantly decreased the abundance of Proteobacteria, Butyrivibrio, and Parabacteroides in rumen fluid (P < 0.05). Correlation analysis showed that the relative abundance of Ruminobacter, Prevotella, and Lactobacillus were significantly positively correlated with unsaturated fatty acids relative contents (P < 0.05). In conclusion, the addition of Clostridium butyricum to the diet can change the microbial composition of the rumen, leading to an increase in the gene expression of SREBP-1C, SCD, PPARγ, and ACC to promote fatty acid deposition, and finally improving the eating quality and nutritional value of small-tailed Han sheep meat.

In order to investigate the effects of lipopolysaccharide (LPS) on the mitochondrial signaling pathway in muscle cells of Tan sheep, M longissimus dorsi muscles from six-month-old Tan sheep were aged at 4 ℃ for 0, 6, 12, 24 and 72 h postmortem and evaluated for pH, ATP content, cell apoptosis rate, cell apoptosis-related enzyme activity, succinatedehydrogenase (SDH) activity, citrate synthase (CS) activity, B-cell lymphoma 2 (Bcl-2) family protein contents, and cytochrome c (Cyt-c) and cysteinyl aspartate specific proteinase 3 (Caspase-3) expression levels. The results showed that the apoptosis rate and Bcl-2-associated X protein (Bax)/Bcl-2 ratio in the control and LPS-induced groups were significantly increased during postmortem aging (P < 0.05). The activities of Caspase-3 and Caspase-9 increased first and then decreased. After LPS treatment, the activities of Caspase-3 and Caspase-9 were higher than those in the control group at all time points. The pH, Cyt-c reduction level and mitochondrial ATP content were significantly decreased overall (P < 0.05). The relative expression level of Cyt-c was significantly increased in both groups at 12 h postmortem, and decreased during 24–72 h in the LPS group. The content of Caspase-3 activated fragment protein in the LPS treatment group was higher than that in control group at the same time points. In conclusion, LPS could activate Caspase-3 and Caspase-9, and reduce the mitochondrial content of ATP and consequently energy metabolism level, thus affecting the activities of SDH and CS, promoting the release of Cyt-C, and increasing Bax/Bcl-2 ratio, and finally inducing cell apoptosis through the mitochondrial signaling pathway.

Foodborne pathogens pose a major challenge to food safety. Dihydroquercetin (DHQ) can be used as a food preservative; however, its antimicrobial mechanism is still unclear. This study found that DHQ had significant antimicrobial activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Proteus vulgaris, Enterobacter aerogenes and Candida tropicalis (P < 0.05), the effect being most pronounced against E. coli. The antimicrobial mechanism against E. coli was investigated. Observation by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that the DHQ-treated cells became distorted and exhibited phenomena such as adhesion, folding, plasmolysis, and the occurrence of vacuoles. DHQ resulted in a significant increase in the level of reactive oxygen species (ROS) inside the cell membrane as determined using a fluorescence probe. The determination of Annexin V-FITC/P kit showed that cell membrane permeability significantly increased with increasing DHQ concentration (P < 0.05) and cell membrane integrity was damaged. Cell membrane potential measurement by Rhodamine 123 staining revealed that DHQ caused cell membrane depolarization, leading to a significant reduction in membrane potential (P < 0.05). Moreover, DHQ caused intracellular Ca2+ leakage, which perturbed the growth, metabolism and functional activity of E. coli. DHQ interfered with the cell cycle of E. coli as determined using propidium iodide/ribonuclease (PI/RNase) staining buffer. These findings revealed that DHQ can inhibit E. coli growth mainly by acting on the cell membrane and consequently affecting the normal passage of cells.

In order to improve the hard texture, poor chewiness and unstable quality of traditional beef jerky, the effect of of ultrasonic power on the quality and myofibrillar protein structure of beef jerky, prepared by ultrasonic-assisted marination at different ultrasonic powers (0, 150, 300, 450 and 600 W) and 30 kHz frequency for 30 min followed by natural fermentation for six days, was explored. The quality characteristics of marinated beef strips and beef jerky such as moisture content, water activity, pH, color, salt content and shear force were evaluated. Meanwhile, changes in the myofibrillar fragmentation index (MFI), surface hydrophobicity, carbonyl group content, and total sulfhydryl and active sulfhydryl group contents of myofibrillar proteins in fresh beef strips after ultrasonic treatment were investigated and sensory evaluation of beef jerky were carried out. Results showed that the pH, moisture content, water activity, salt content, L* value and b* value of beef jerky increased with the increase in ultrasonic power, while the shear force decreased. Ultrasonic treatment increase the a* value, whereas the opposite effect was observed at excessively high ultrasonic power. With the increase in ultrasonic power, the MFI, surface hydrophobicity, active sulfhydryl group content and carbonyl group content of myofibrillar proteins increased, while the total sulfhydryl group content decreased (P < 0.05). Sensory evaluation showed that beef jerky with ultrasonic treatment at 300 W had the best overall acceptability. In summary, to maintain color stability and avoid excessive oxidation of protein and energy waste, an ultrasonic power of 300 W was determined as the optimal treatment condition, which could significantly improve the overall quality of beef jerky.

The retrogradation of rice starch is the major factor that restricts its application. Recent studies have suggested that extrusion combined with glutelin has an obvious inhibitory effect on the retrogradation of rice starch. This study was executed in order to clarify the influence of extrusion parameters including screw speed, extrusion temperature, raw material moisture content and mass ratio of rice starch to glutelin on the retrogradation properties of rice starch-glutelin mixed system. Furthermore, how extrusion treatment could delay the regeneration of the mixed system was analyzed using a rapid viscosity analyzer (RVA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, low-field nuclear magnetic resonance (LF-NMR), scanning electron microscopy (SEM), laser scanning confocal microscopy (LSCM) and a rheometer. The results showed that the most pronounced retarding effect on the retrogradation of the mixed system was observed when the screw speed was 300 r/min, the extrusion temperature was 90 ℃, the moisture content of the raw material was 34%, and the starch/protein ratio (material ratio) was 91:9. Extrusion treatment significantly decreased the peak viscosity, disintegration value and retrogradation value of the composite system from (3 005.00 ± 25.00), (1 193.00 ± 6.00), and (164.33 ± 3.51) cP to (429.00 ± 5.00), (213.00 ± 3.00) and (27.05 ± 0.14) cP, respectively (P < 0.05), and reduced the relative crystallinity from (20.18 ± 0.13)% to (2.17 ± 0.43)%. Moreover, the endothermic peak of the mixture disappeared, and the ratio between the peak intensities at 1 047 and 1 022 cm−1 in the infrared spectra was decreased significantly to 0.43 ± 0.08 (P < 0.05). After extrusion treatment, the microstructure became more uniform and compact, the water retention property was enhanced, the shear stress was decreased, the hysteresis loop area was increased, and the storage modulus (G’) and the loss modulus (G”) were decreased, indicating good resistance to retrogradation. The results of this study provide a theoretical reference for the application of extrusion treatment in delaying the retrogradation of rice starch–glutelin mixed system.

To investigate the effects of ultra-high pressure (UHP) treatment and vegetable oil addition on its heat-induced gel properties, rabbit myosin was subjected to UHP treatments (10 ℃/2 min) at different pressure levels (100, 150 and 200 MPa), and then mixed with different amounts (0%, 10%, 20% and 30%) of soybean oil and phosphate buffer to prepare emulsion systems, whose heat-induced gelation was carried out at a programmed heating rate of 1 ℃/min. Myosin not treated by UHP served as control. The storage modulus G’, loss modulus G”, gel strength, water-holding capacity (WHC), microstructure and relaxation time spectra of heat-induced myosin gels were measured by rheometer, texture analyzer, scanning electron microscope (SEM) and low-field nuclear magnetic resonance spectroscopy (NMR). The results showed that compared with the control group, the storage modulus, loss modulus, gel strength and WHC of heat-induced myosin gels were increased significantly by high pressure treatment and the addition of soybean oil. SEM revealed that the three-dimensional network structure became denser and more compact. The NMR analysis showed that the relative content of free water in the gel matrix gradually decreased with an increase in pressure, and the degree of proton binding of immobilized water and the relative content of bound water significantly increased. Under the same pressure, the G’, G”, gel strength and WHC increased with increasing addition of soybean oil, showing significant differences among addition levels (P < 0.05). The 200 MPa + 30% soybean oil group had the best heat-induced gel properties. Therefore, appropriate high-pressure treatment combined with the addition of soybean oil enhanced the interaction between protein and fat, and changed the microstructure and water distribution state and consequently gel properties such as rheological properties, texture and WHC of heat-induced myosin gels, which played a positive role in improving the functional properties of heat-induced rabbit myosin gels.

In this study, we investigated the effect of high hydrostatic pressure (HHP) treatment on the physicochemical and structural properties of corn starch/ferulic acid (CS/FA) composite system by differential scanning calorimetry (DSC), rheometer, Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD). The results showed that HHP treatment enhanced the peak viscosity, elastic modulus G’ and viscous modulus G”, and reduced the solubility and degree of expansion (75–95 ℃), enthalpy of gelatinization, and retrogradation value of the composite system. In addition, HHP treatment increased the particle size of the composite system, and FTIR and XRD spectra showed that the short-range ordered and double helix structure of the composite system decreased after HHP treatment; the starch particles were still A-type, but the relative crystallinity decreased. In summary, HHP treatment promoted the interaction between corn starch and ferulic acid in the composite system, improved the physicochemical properties of corn starch, and reduced its ordered structure.

The effect of multi-frequency pulsed ultrasound (20 kHz, 20 + 28 kHz, and 20 + 28 + 40 kHz) on characteristics of a peach pulp-κ-carrageenan blend gel system containing erythritol as a cosolute was systematically studied. Rheological analysis showed that the blend gel system was a pseudoplastic fluid. With the increase in pulsed ultrasound frequency, the consistency coefficient increased and the flow index decreased. Dynamic rheological analysis showed that single-frequency and dual-frequency pulsed ultrasound could significantly enhance the elastic modulus (G’) and viscosity modulus (G”), while triple-frequency pulsed ultrasound had the opposite effect. The particle size was significantly reduced by the cavitation effect produced by multi-frequency pulsed ultrasound, the effect being most pronounced with triple-frequency pulsed ultrasound. Compared with the control group, D50, D[4,3], and D[3,2] of the samples treated by triple-frequency pulsed ultrasound were decreased by 12.32%, 9.80% and 7.57%, respectively. Additionally, multi-frequency pulsed ultrasound could increase the absolute value of the phase angle and conductivity, and reduce the impedance value. Compared with the control group, the absolute value of the phase angle and the conductivity were increased by 35.82% and 10.15% in the triple-frequency pulsed ultrasound group, respectively; and the impedance value was reduced by 38.52%. As the pulsed ultrasound frequency increased, the association between the blend system and water was enhanced, so that a bound water signal appeared. No new absorption peaks were found in the Fourier transform infrared spectra of ultrasound-treated samples, indicating that ultrasound treatment did not destroy the functional groups, but instead only strengthened hydrogen bonding. The micropores of the blend gel system were enlarged by both single-frequency and dual-frequency pulsed ultrasound treatments, while triple-frequency pulsed ultrasound treatment resulted in denser and more uniform pores. This study can provide a reference for improving the quality of blend gels of κ-carrageenan and developing gel-like peach pulp products.

In this study, free radical oxidation was chosen to induce covalent reaction of gliadin (GL) with epigallocatechin gallate. The effects of different ultrasound (US) powers on the enhancement of the covalent reaction were compared with the aim of improving the bioavailability of polyphenols in protein modification. Covalent modification of polyphenols was verified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), high-performance liquid chromatography (HPLC) and the Folin-Ciocalteu assay. The structural changes of the covalent complexes were analyzed by ultraviolet (UV) spectroscopy and circular dichroism (CD) spectroscopy. The results showed that US disrupted weak intra-protein forces, which caused molecular depolymerization. The hydrophilic/hydrophobic amino acid residues of the protein were shifted and the tertiary structure tended to be looser, and this process altered the distribution of groups on the molecule surface and increased the water solubility of the protein. Furthermore, the shift in the spatial structure of GL resulted in the exposure of more enzyme cleavage sites, making its digestion easier. The synergistic effect of US and free radical oxidation increased the loading of antioxidant molecules onto the covalent complexes, resulting in stronger free radical scavenging activity.

In order to explore the effects of different drying methods on the physicochemical properties and microstructure of Penaeus vannamei, the drying characteristics, color, texture, water distribution, astaxanthin content, antioxidant capacity and microstructure of P. vannamei were analyzed after medium-short wave infrared drying (MSWID) or hot air drying (HAD). The results showed that with the increase in drying temperature, the moisture content of P. vannamei decreased gradually, and MSWID could reduce the drying time of P. vannamei by 16.67% and make its color brighter compared with HAD at 70 ℃. The hardness, gumminess and chewiness of P. vannamei were significantly increased with increasing drying temperature (P < 0.05), but the springiness was not significantly affected by drying temperature (P > 0.05). According to magnetic resonance imaging (MRI) results, the rate of water migration during MSWID was faster than that during HAD. Besides, the results of microstructure observation indicated that the muscle fiber of P. vannamei became looser and more porous after MSWID compared with HAD. For both drying treatments, the α-helix relative content of shrimp proteins first increased and then decreased, and the β-fold relative content showed a contrary trend. The astaxanthin content of MSWID dried shrimp was lower than that of HAD dried shrimp, and so was the antioxidant capacity. The quality of MSWID dried P. vannamei was better than that of HAD dried P. vannamei, indicating MSWID to be a promising drying method for P. vannamei.

This study was implemented in order to explore the effect of ultrasound-assisted H2O2-Vitamin C (VC) degradation on ginseng polysaccharides (GPS). GPS were extracted from ginseng by water extraction followed by alcohol precipitation and separated and purified by DEAE-52 cellulose and Sephadex G-100 column chromatography. Fraction GPS-1A was degraded into a low-molecular-mass polysaccharide DGPS-1A under the following conditions: sample concentration 4.2 mg/mL, H2O2-VC concentration 10.3 mmol/L and ultrasound power 1 006 W. Meanwhile, the structural characteristics of GPS-1A and DGPS-1A, their inhibitory effects on major starch digestive enzymes and their antioxidant activities were studied. The results showed that the relative molecular masses of GPS-1A and DGPS-1A were 135 and 77.8, respectively, but the composition of monosaccharides did not change after ultrasound-assisted H2O2-VC degradation. The Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectra also showed that the major functional groups of the polysaccharide were not damaged after degradation. In addition, DGPS-1A showed stronger in vitro antioxidant and hypoglycemic activities than did GPS-1A. At the maximum concentration (6 mg/mL), the inhibition rates of α-glucosidase and α-amylase and the scavenging rates of 1,1-diphenyl-2-trichrophenylhydrazine radical (DPPH) and hydroxyl radical by DGPS-1A were (90.83 ± 3.04)%, (78.03 ± 2.29)%, (89.56 ± 1.17)% and (76.85 ± 1.63)%, compared to only (65.16 ± 2.53)%, (54.04 ± 1.97)%, (31.77 ± 2.42)% and (30.85 ± 2.29)% with GPS-1A, respectively. Moreover, the reducing power of DGPS-1A was 2.03 times higher than that of GPS-1A. These results indicate that ultrasound-assisted H2O2-VC degradation of ginseng polysaccharides has potential application in the development of functional foods with antioxidant and hypoglycemic activities.

In order to investigate the effect of ultrasound-assisted fermentation on its flavor and quality, mackerel enzymatic hydrolysate was, fermented with Saccharomyces longosporus to enhance the flavor, and flavor and quality changes during different fermentation stages were monitored by measurement of total bacterial count and amino acid nitrogent content, sensory evaluation, and principal component analysis (PCA) of electronic nose data. Meanwhile, nutritional evaluation of the fermented product was carried out by analysis of free and essential amino acid composition, and the composition of flavor compounds was analyzed by gas chromatography-ion mobility spectrometry (GC-IMS). It was found that PCA effectively distinguished the flavor differences between the ultrasound and control groups during the fermentation process. The total bacterial count, amino acid nitrogen content and sensory score of the ultrasound group were higher than those of the control group during the whole fermentation process. On day 12 of fermentation, the ultrasound group had the best flavor quality with a total bacterial count of 8.90 (lg(CFU/mL)) and an amino acid nitrogen content of 0.78 g/100 g, and the fermented product had a rich umami taste and a fruity aroma. Moreover, the content of total free amino acids in the fermented product was 6.373 g/100 g, and the essential amino acid index (EAAI) value was 82.90, indicating a high nutritional value. GC-IMS results showed that the contents of off-flavor compounds such as, saturated straight-chain aldehydes gradually decreased, or even disappeared after 12 days of fermentation. In contrast, the contents of unsaturated alcohols and aroma-active substances (ketones and esters) significantly increased in the ultrasonic group compared with the control group. Thus, ultrasound-assisted treatment could improve the flavor quality of fermented mackerel enzymatic hydrolysate. This study may provide a theoretical basis for the application of ultrasonic technology in the development of seafood seasoning.

To investigate the effect of ultrasonic cleaning treatment on the quality of pork, the water-holding capacity, nutrients, shear force, and flavor compounds of raw pork washed by ultrasonicfor 0–­30 minutes were measured, and the data obtained were evaluated by principal component analysis (PCA). The results showed that the total volatile basic nitrogen (TVB-N) and thiobarbituric acid reactive substance (TBARS) values of pork treated by ultrasonic for 30 minutes were the lowest, (8.45 mg/100 g and 0.36 mg/kg, respectively), and the shear force significantly decreased to 33.92 N. The pork treated by ultrasonic for 20 minutes had the lowest pressing loss (17.99%). Ultrasonic cleaning could cause slight loss of trace metal elements, but did not affect the nutritional composition, cooking loss, or pH of pork. Compared with the control group, the relative contents of aldehydes and alcohols in the ultrasonic treated pork significantly decreased, the types and relative contents of hydrocarbon acid ketone esters significantly increased, and the overall flavor was improved. Linear discriminant analysis (LDA) of electronic nose data showed that there was a correlation between the flavor improvement and the duration of ultrasonic cleaning treatment. PCA results showed that the quality of pork was significantly different before and after ultrasonic cleaning. In summary, appropriate ultrasonic cleaning improved the water-holding capacity and tenderness of pork, and significantly improved its storage quality and flavor, but had little impact on its nutrients.

Objective: This study aimed to compare the compositions of peptides from Engraulis japonicus and Glycine max and their immunomodulatory effects on the intestinal mucosa in mice. Methods: The sequences of peptides from E. japonicus and G. max were analyzed by ultra-performance liquid chromatography-high resolution mass spectrometry (UPLC-MS/MS) combined with Peaks Online 1.7 software, and the differences in peptide composition were compared. The effects of the two peptides on the mucosal structure, immune factors, immunoglobulin (Ig) levels, and gene expression of factors associated with the Toll-like receptors (TLRs)/nuclear factor kappa B (NF-κB) signaling pathway in the small intestine of mice with cyclophosphamide-induced immunosuppression were investigated. Results: The peptide compositions from E. japonicus and G. max were quite different. Only 11% of the peptide sequences were identical between them. Administration of the peptides from E. japonicus and G. max at 300 mg/kg mb for 30 d could significantly increase the spleen index and thymus index, alleviate intestinal mucosal damage, increase the length of intestinal villi and decrease the depth of crypts in cyclophosphamide-induced immunosuppressed mice. Moreover, the inhibitory effect of cyclophosphamide on the expression of tumor necrosis factor-α (TNF-α), interferon-gamma (IFN-γ), interleukin-4 (IL-4), and IL-13 was ameliorated, and the secretion of IgA and secretory IgA and the gene expression of TLR-4, TLR-6, TLR-9 and NF-κB were upregulated in the small intestine mucosa. Conclusion: The peptides from E. japonicus and G. max can promote the secretion of immune factors and immunoglobulins in the small intestinal mucosa and alleviate cyclophosphamide-induced intestinal mucosal damage and immunosuppression in mice by protecting the TLRs/NF-κB signaling pathway. Although the average molecular masses, amino acid compositions and polypeptide compositions of the two peptides are different and the protective effect of the peptides from E. japonicu on secretory IgA in the intestinal mucosa is more pronounced than that of the peptides from G. max, there is no significant difference between their efficacy in protecting intestinal mucosal structure and regulating mucosal immunity in mice.

The intestinal flora of the human body is closely related to health. Gut microbiota dysbiosis will lead to intestinal dysfunction and, consequently, a variety of intestinal diseases. In this study, subjects with different diseases were requested to take one of three microecological agents, stachyose, composite probiotics (CPb) and synbiotic MF-13. An Ion Torrent PGM™ sequencing platform was used to analyze the structure of intestinal microflora and the contents of cholesterol and bile acid in the feces of the subjects were measured. Our aim was to investigate the regulatory effect of intervention with microecological agents on the intestinal microflora structure and lipid metabolism. The results showed that 1 067 operational taxonomic units (OUT) were obtained from the fecal microbial samples from all subjects. The dominant bacteria were Firmicutes and Bacteroidetes, altogether accounting for 91.65%, and Bacteroidetes accounting for about 70.10% of the total number of sequences. Bacteroides and Prevotella were the dominant genera, accounting for 33.1% and 33.8% of the total sequences, respectively. At the phylum level, stachyose promoted the proliferation of Bacteroidetes, but inhibited the proliferation of Firmicutes. CPb had no significant effect on the abundance of each phylum, while MF-13 promoted the proliferation of Proteobacteria and Actinobacteria. Stachyose significantly decreased the abundance of Sutterella in subjects with constipation and insomnia, CPb significantly decreased the abundance of Sutterella in subjects with diarrhea, and MF-13 increased the abundance of Parabacteroides. The analysis of intestinal microflora diversity showed that Chao1 index significantly increased during the early period of MF-13 intervention, while there were no significant changes in other diversity indexes. Cluster analysis and non-metric multi-dimensional scaling (NMDS) analysis showed that microecological preparation intervention changed the intestinal microbiota structure in most of the samples, and the microflora structure of all populations showed an overlapping tendency. The intestinal microflora species that significantly differed between individuals were analyzed using Metastat statistics, and it was found that there was no significant change in the abundance of OTUs before and after intervention with each microecological agent, while there was a significant difference between individual subjects. MF-13 significantly promoted the fecal excretion of cholesterol and bile acids (P < 0.05). In conclusion, stachyose has an obvious influence on the intestinal microflora structure of volunteers, while CPb and MF-13 do not. However, MF-13 can increase the intestinal excretion of cholesterol and bile acid, which is beneficial to the metabolism of intestinal cholesterol, but the durability of this effect is poor.

This study intended to investigate the efficacy of dietary fiber in preventing obesity and regulating the intestinal microflora. C57BL/6 mice were fed D12492 high-fat diet supplemented with pomelo peel, insoluble dietary fiber (IDF) from pomelo peel or soluble dietary fiber (SDF) from pomelo peel. Those fed a maintenance diet or the high-fat diet served as normal control and obesity control groups, respectively. The feeding period lasted for 67 days. The changes in food intake, body mass, blood biochemical indexes, visceral indexes and intestinal microflora of the mice were observed during the feeding period. The results showed that compared with the obesity control group, body mass, serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels, epididymal fat coefficient and Lee’s index decreased by 4.9%, 8.3%, 14.29%, 0.44% and 2.54% in the IDF group, decreased by 5.1%, 11.4%, 21.21%, 0.60% and 2.47% in the SDF group, but increased by 1.3%, 7.4%, 12.5%, 0.96% and 1.27% in the pomelo peel group, respectively. The concentration of HDL-C increased by 0.52%, 0.78% and 5.44% in the IDF, SDF and pomelo peel groups, respectively. Moreover, dietary fiber from pomelo peel increased the relative abundance of Bacteroidetes and Lachnospiraceae_NK4A136_group, and decreased the relative abundance of Firmicutes, Desulfobacterota and Deferribacterota. Therefore, both SDF and IDF from pomelo peel have a significant effect on preventing obesity and lowering blood lipids, probably not by inhibiting food intake but rather by increasing the relative abundance of Bacteroidetes and Lachnospiraceae_NK4A136_group, and decreasing the relative abundance of Desulfobacterota and Deferribacteres. The increase in the relative abundance of Firmicutes is not significantly correlated with body mass, but significantly positively correlated with HDL-C and negatively correlated with LDL-C, which is beneficial to lipid control. The increase in the relative abundance of Bacteroidetes is significantly negatively correlated with body mass, TC and HDL-C levels, and significantly positively correlated with LDL-C levels, which is conducive to body mass control, but not blood lipid control. Hence, the effects of Bacteroidetes and Firmicutes on body mass and blood lipids need to be further studied. Pomelo peel dietary fiber can increase body mass and LDL-C levels by increasing food intake, but also significantly increase HDL-C levels. Similarly, its benefits in controlling body mass and blood lipids need to be further confirmed.

The aim of this study was to investigate the effects of arabinoxylan and its blend with β-glucan on fecal metabolites in mice with high-fat diet-induced obesity. Sixteen male ICR/KM mice were randomly divided into four groups: normal diet (CON), high-fat diet (HFD), high-fat diet supplemented with arabinoxylan (HFAX) and high-fat diet supplemented with arabinoxylan + β-glucan (HFAβ). The composition and content of fecal metabolites in each group of mice were investigated by 1H-NMR-based metabolomics. The results showed that a total of 67 small molecule metabolites, including amino acids, peptides, organic acids, carbohydrates, nucleosides, nucleotides and their derivatives, were identified. Compared with the normal diet group, the HFD group had significantly higher levels of fecal cholate, xanthine and pyroglutamate (P < 0.05) and significantly lower levels of valine, acetoacetate, 4-hydroxyphenylacetate, 3,4-dihydroxybenzeneacetate, phenylacetate, glutamine, isoleucine and asparagine (P < 0.05). Compared with the HFD group, the concentrations of glutamine, acetate, 4-hydroxyphenylacetate, glucose, asparagine, isobutyrate and threonine increased significantly in the arabinoxylan supplement group (P < 0.05), while the concentrations of nicotinate, pyroglutamate and cholate decreased significantly (P < 0.05). In particular, compared with the HFAX group, the amount of pyroglutamate increased significantly (P < 0.05), while the levels of acetate, butyrate, glucose, glutamine, isobutyrate and propionate decreased significantly in the HFAβ group (P < 0.05). The metabolic pathway and enrichment analysis revealed that the major pathways included the synthesis and degradation of ketone bodies, phenylalanine, tyrosine and tryptophan biosynthesis, tyrosine metabolism, butanoate metabolism, and alanine, aspartate and glutamate metabolism. In conclusion, arabinoxylan and its mixture with β-glucan supplementation could improve fecal metabolomic profiles in mice with high-fat diet-induced obesity.

Ulcerative colitis is a chronic inflammatory bowel disease with unclear pathogenesis, and its incidence is increasing gradually. Recently, with the popularization of the concept of healthy diet, reducing the risk of ulcerative colitis through dietary intervention has become increasingly popular. In this paper, we report on the protective effect of Gallus gallus domesticlus Brisson peptides on dextran sodium sulfate (DSS)-induced ulcerative colitis in mice. For this purpose, we measured changes in body mass, disease activity index (DAI), colon length, hematoxylin-eosin (HE) stained colon sections, the levels of pro-inflammatory cytokines such as interleulin-6 (IL-6), IL-10, IL-1β and tumor necrosis factor-α (TNF-α), intestinal microbial community composition and the levels of short-chain fatty acids in cecal contents. The results indicated that G. gallus domesticlus Brisson peptides significantly alleviated the symptoms of ulcerative colitis such as body mass loss, hematochezia, diarrhea, and the shortening of colon length and colon tissue injury in mice, and significantly decreased the levels of TNF-α, IL-1β and IL-6. In addition, G. gallus domesticlus Brisson peptides alleviated intestinal microflora disturbance induced by DSS, down-regulated the relative abundance of Shigella and Clostridiaceae_Clostridium, increased the relative abundance of Akkermansia, Ruminococcus and Oscillospira, and significantly increased the contents of acetic acid, propionic acid and butyric acid in cecal contents, thereby alleviating colon inflammation induced by DSS in mice.

In order to explore the effect of exogenous glucose (Glc) treatment on the postharvest storage quality and antioxidant metabolism of apricot fruit, ‘Saimaiti’ apricot fruit from Xinjiang were stored for up to 49 days at (0 ± 1) ℃ and a relative humidity of 90%–95% after vacuum osmosis treatment (holding for 2 min at 0.05 MPa followed by soaking for 5 min at atmospheric pressure) with different concentrations (100, 200 and 400 mmol/L) of Glc or distilled water as a control. Fruit quality and antioxidant metabolism-related indexes were determined during the storage period. The results showed that exogenous Glc treatment could effectively maintain the firmness, soluble solids content (SSC) and titratable acid (TA)levels, and significantly reduce the respiration intensity of apricot fruit, with the most pronounced effect being observed at 200 mmol/L Glc. In addition, exogenous Glc treatment increased the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR) in apricot fruit compared with the control group, and effectively maintained the contents of ascorbic acid (ASA) and glutathione (GSH), thus delaying the accumulation of superoxide anion radical, hydrogen peroxide, malondialdehyde (MDA) and the increase of cell membrane permeability. These findings indicate that exogenous Glc treatment could maintain the storage quality of apricot fruit by regulating its antioxidant metabolism during storage, which will provide a theoretical basis and technical reference for the application of Glc in postharvest storage and preservation of fruits and vegetables.

Sour rot disease, caused by Geotrichum citri-aurantii, is one of the major postharvest diseases of citrus. In this study, the inhibitory effect of trans-2-hexenal combined with soluble salts on G. citri-aurantii and sour rot disease was investigated through in vitro and in vivo experiments. Results showed that sodium phosphate had a strong antifungal activity against G. citri-aurantii, with minimal inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of 4.00 and 16.00 mg/mL, respectively, whereas sodium diacetate had relatively poor inhibitory effect, with both MIC and MFC of 16.00 mg/mL. However, the growth of G. citri-aurantii could not be completely inhibited by calcium propionate at 16.00 mg/mL. The in vitro experiments showed that the combination of trans-2-hexenal with sodium phosphate, sodium diacetate or calcium propionate resulted in a synergistic effect, with both MIC and MFC of 0.23 mg/mL. When trans-2-hexenal was combined with sodium dehydroacetate, it resulted in an additive effect, with both MIC and MFC of 0.46 mg/mL. The in vivo experiments showed that the combination of trans-2-hexenal at 5 × MFC and 10 × MFC with sodium dehydroacetate had the best inhibitory effect on the development of sour rot disease in citrus fruit inoculated with G. citri-aurantii, and the incidence rate was 0% after six days, which was significantly lower than that observed in the control group (100%). The combination of trans-2- hexenal and sodium dehydroacetate can effectively inhibit the growth of G. citri-aurantii and reduce the incidence of sour rot disease of citrus.

We performed this study in order to evaluate the control effect and mechanism of the biosurfactant rhamnolipids (RLS) on black spot disease caused by Alternaria alternata in pear fruit. The results showed that RLS treatment at a mass concentration of 20 mg/mL effectively enhanced resistance to A. alternata, and the lesion diameter was only 64.29% of that of the control group at 12 days following the treatment. Furthermore, it was shown that compared to the control group, RLS treatment significantly increased the activities of phenylalanine ammonia lyase (PAL), cinnamate acid 4-hydroxylase (C4H), 4-coumarate coenzyme A ligase (4CL), and cinnamyl alcohol dehydrogenase (CAD), as well as the contents of total phenols and flavonoids in pear fruit tissue. The activities of chitinase and β-1,3-glucanase were significantly induced. The activities of NADPH oxidase (NOX), superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), and the contents of H2O2 and superoxide anion radical in the early and middle stages of storage were also increased by RLS treatment. Meanwhile, the ascorbate-glutathione (ASA-GSH) cycle was activated to maintain the dynamic balance of reactive oxygen species (ROS) production and scavenging in pear fruit tissue, and the membrane permeability and the content of malondialdehyde (MDA) were reduced. Collectively, this study suggested that post-harvest rhamnolipid treatment can enhance black spot disease resistance in pear fruit by regulating phenylpropane metabolism, ROS metabolism and pathogenesis-related proteins.

In this study, the changes in myofibrillar protein oxidation, taste substance and taste characteristics of dried Penaeus vannamei were investigated under accelerated storage conditions, and a correlation analysis was carried out between myofibrillar protein oxidation and taste characteristics. As a result, the color of dried Penaeus vannamei gradually changed to dark brown, the content of total sulfhydryl group decreased, and the carbonyl group content and surface hydrophobicity increased, which indicated increased degree of oxidation of myofibril protein. The content of inosine monphosphate and umami free amino acids in dried shrimp showed a trend of first increasing and then decreasing, while the contents of sweet free amino acids and total free amino acids decreased gradually. The electronic tongue was used to characterize the taste change of dried Penaeus vannamei, and it was found that the umami and sweetness intensity of dried Penaeus vannamei decreased, the bitterness intensity increased, but the saltiness intensity did not obvious change. The richness first increased and then decreased. The correlation analysis between protein oxidation and taste indexes showed that the degree of protein oxidation of dried Penaeus vannamei was positively correlated with the bitterness intensity, and negatively correlated with the umami, sweetness, saltiness intensity and richness. These results showed that there was no significant difference in the taste of dried white shrimp during short-term storage, but with the extension of storage time, the appearance and color deteriorated, the oxidation of myofibrillar protein increased, and the taste quality decreased. The findings from this study provide a theoretical and data basis for regulating the storage quality of white shrimp.

In order to develop sustained-release films with excellent performance, this study used polyvinyl alcohol (PVA) and chitosan (CS) as a film-forming substrate, β-cyclodextrin (β-CD) as a sustained-release agent, and oregano oil (OEO) as an antibacterial and antioxidant to prepare β-CD/CS/PVA composite films with different amounts of added OEO. The effects of addition of different amounts of OEO on the basic properties, physicochemical structure, antibacterial and antioxidant properties, and slow-release performance of the composite films were investigated. Fourier transform infrared (FTIR) spectroscopy indicated that none of the components altered the structure of the composite film. Increasing the content of OEO improved the ductility, hydrophobic properties, and light barrier properties, and also significantly increase the antibacterial and antioxidant capacities (P < 0.05). The diameters of inhibition zones of the composite film with 2% OEO against Staphylococcus aureus and Escherichia coli was 8.42 and 9.24 mm, respectively, and its DPPH radical scavenging rate was 80.84%. The composite film had excellent sustained-release performance in 95% ethanol, and the active substance in the composite films with 0.5% and 1.5% OEO could be released continuously for 540 min in this medium. It was concluded that the composite film with 2% OEOs had good overall performance, showing great potential for development.

The effect of γ-aminobutyric acid (GABA) treatment on chilling injury in cold-stored kiwifruit and its relationship with reactive oxygen species (ROS) metabolism were investigated. Postharvest kiwifruit were treated with 2.0 mmol/L GABA solution for 20 min and stored at (4 ± 1) ℃ and (85 ± 5)% relative humidity. Chilling injury development was evaluated and the changes in the dynamic balance between the production and removal of ROS were analyzed. The results showed that compared with the control group, GABA treatment could delay the increases in the chilling injury index, cell membrane permeability and malondialdehyde (MDA) content of cold-stored kiwifruit, inhibit the rate of superoxide anion radical production and the increase in hydrogen peroxide content, and increase and maintain superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR) and dehydroascorbate reductase (DHAR) activities. Moreover, GABA treatment slowed down the decrease in the contents of ascorbic acid and glutathione, which contributed to higher antioxidant capacity levels in the fruit. The above findings indicated that exogenous GABA treatment could maintain dynamic redox balance, attenuate membrane lipid peroxidation and preserve cell membrane integrity in cold-stored kiwifruit by inhibiting the accumulation of ROS, and increasing the activities of the enzymatic and non-enzymatic ROS systems, thereby enhancing cold stress resistance and ultimately delaying chilling injury.

Pyrethroids (PYRs) are widely used as pesticides due to low toxicity and high efficacy; however, PYRs residues have caused increasingly serious environmental and food safety problems. 3-Phenoxybenzoic acid (3-PBA), one of the major intermediate degradation products of PYRs, is more stable and toxic than the parent pesticides, and its residue can further aggravate environmental and agricultural product pollution. In recent years, filamentous fungal degradation of PYRs and 3-PBA has been reported, and research on this topic mainly focuses on strain screening, degradation characteristics, degradation pathways and localization of degradation enzymes. Unfortunately, key enzymes and their encoding genes involved in the degradation process are rarely reported. With the development of sequencing technology, molecular biology technology has provided a new strategy to mine PYR-degrading enzymes and their encoding genes in filamentous fungi. In this article, the basic properties, residues status and hazards of PYRs and 3-PBA are described. The filamentous fungi capable of degrading PYRs and 3-PBA, and their degradation pathways and degrading enzymes are reviewed. In addition, future prospects for the development of methods for screening and verification of degrading enzymes and their encoding genes are discussed. We expect that this review will provide a theoretical basis for understanding the degradation pathways and mechanisms of PYRs and 3-PBA by filamentous fungi and provide a reference for reducing residual pesticides in the environment and agricultural products.

Zein, soy protein and whey protein can interact with lecithin to form composite systems. Proper application of ultrasonic, high-pressure homogenization and spray drying can make the composite systems more stable, expanding their application in delivery systems and making them promising for application in the fields of food, medicine, and other industries. This review focuses on the effect of the three physical field techniques on the interactions of the three proteins with lecithin and their application to deliver bioactive substances and drugs. We believe that this review will provide a basis for improving the stability of protein-lecithin composite systems and its application in delivery systems.

Under the influence of the production process, fermented meat products are easily contaminated during processing and storage, posing safety risks and causing harms to human health. In this paper, the biological, chemical, physical and other hazardous factors of fermented meat products and the biological, chemical and physical control measures against these factors as well as their underlying mechanisms are systematically reviewed. Finally, the problems currently existing in the prevention and control of the harmful factors and follow-up research directions are discussed. Hopefully this review will provide a theoretical basis for the research and development of fermented meat products.

With the rapid development of the food industry and the growing concerns about food safety, it is particularly significant to develop fast, convenient and accurate techniques for food analysis and testing. In the analysis of food safety, due to the complex matrix composition and the low concentration of the target compounds, selecting the appropriate sample pretreatment method and extraction adsorbent is important for achieving good extraction efficiency. Two or more interactions of mixed-mode adsorbents with target compounds of the same type can occur simultaneously, and mixed-mode adsorbents can also interact with multiple target components with different properties simultaneously, resulting in increased adsorption selectivity and capacity compared to single-mode adsorbents. Hence, in this article, the classification, characteristics and application of mixed-mode adsorbents in the field of food analysis are reviewed with the purpose of providing a reference for researchers in the selection, preparation and application of mixed-mode adsorbents and of boosting the development of mixed-mode adsorbents in the field of food analysis.

Mycotoxins can enter and accumulate in the human body through contaminated foods, which is extremely harmful to human health. A rapid, sensitive, accurate and effective method is needed to detect mycotoxin contamination. With the advancement of science and technology, various types of biosensors have been continuously developed. Among them, magnetic and fluorescent sensors can produce sensitive and fast optical responses to the target compounds. This dual-function sensor has been widely used in the field of biological detection. This article reviews the application and future prospects of biosensors combining Fe3O4 magnetic nanoparticles with organic fluorescent materials, quantum dots, up-conversion nanoparticles, metal nanoclusters or fluorescent carbon nanomaterials in the detection of mycotoxins. This review is expected to provide a reference for further research and application of Fe3O4 magnetic and fluorescent sensors.

Aroma compounds are the general term for esters, aldehydes, alcohols, ketones, terpenes, organic acids and other compounds responsible for aromas, which have been widely used in food, medicine, cosmetics, agriculture and other fields. With the economic development and the improvement of the quality of life in China, the demand for aroma compounds is gradually increasing. Microbial fermentation is becoming an important way to obtain green aroma compounds. In this paper, recent progress in the production of various aroma compounds by microorganisms is summarized, and the sources and isolation of aroma-producing microorganisms, the types of microorganism-derived aroma compounds, the factors affecting the microbial production of aroma compounds and related processing technologies, and the strategies for improving the microbial production of aroma compounds are reviewed. This review is expected to provide an important reference for the research and development of aroma-producing microorganisms.

Being nutritious, aquatic products are loved by consumers. However, aquatic products are prone to bacterial spoilage, posing safety risks to consumers. The current research proves that bacterial spoilage capacity and virulence are often regulated by its quorum sensing (QS) system, so using quorum sensing inhibitors (QSIs) to intervene in the QS system is an effective way to control bacteria. Currently, more and more QSIs have been discovered from microorganisms, plants and animals. Along with the development of biological engineering, cheminformatics and nanotechnology, artificial QSIs have been synthesized. In order to provide a reference for quality and safety control of aquatic products based on QS inhibition, this article reviews the QS systems of seveal common aquatic product-borne pathogenic and spoilage bacteria and the modes of regulatory effects of the QS systems on virulence factors, with a focus on the current status of research on microbial-, plant-, animal-derived and synthetic QSIs.

Human health is closely related to the gut microbiota. Gut microbiota disorders can lead to various diseases including colitis, food allergy, obesity, and constipation. Prebiotics play an important role in improving the growth of intestinal probiotics and maintaining intestinal homeostasis. Considering that prebiotics play a positive role in regulating the gut microbiota and protecting human health, this paper reviews recent progress in understanding the roles of soybean prebiotics in enriching the intestinal probiotics, inhibiting the intestinal colonization of pathogenic bacteria, improving the production of short-chain fatty acids and the absorption of nutritional substances, enhancing the intestinal immune system, and protecting human health. This review will hopefully provide theoretical guidance for intervening in human health through regulation of the gut microbiota by soybean prebiotics.

Flaxseed is one of the eight major oil crops in China, and flaxseed oil is a healthy vegetable oil rich in α-linolenic acid, which is highly favored by consumers. Volatile flavor substances are a key attribute affecting the quality of flaxseed oil and its popularity among consumers. This article provides a systematic overview of recent advances in the research on volatile flavor substances in flaxseed oil, with a focus on the techniques and methods for the extraction, analysis and detection of volatile flavor substances in flaxseed oil from the perspective of molecular sensory science, the material basis and aroma characteristics of volatile flavor in flaxseed oil, and the factors affecting the flavor formation of flaxseed oil. Moreover, it also summarizes the possible formation pathways of some key flavor substances during the processing of flaxseed oil. It is hoped that this review will provide a theoretical basis for improving the flavor of linseed oil.

Phytic acid widely exists in plant foods, which is the main storage form of phosphorous in plant seeds. Recently, phytic acid in foods has attracted increasing research attention due to the antinutritional properties of phytic acid and its degradation products such as chelating with mineral ions and reducing protein bioavailability. In this paper, the characteristics, antinutritional quality and physiological activities of phytic acid and its degradation products lower inositol phosphates, as well as their contents in foods are summarized. Moreover, the analytical methods for these compounds in foods are highlighted and the advantages and disadvantages of various analytical methods are analyzed and compared. It is anticipated that this review will provide a reference for the precise detection of phytic acid and its degradation products and for the formulation of recommended intake for phytic acid from foods in China.

Selenium nanoparticles (SeNPs), elemental selenium particles at the nano-size scale, have great potential for applications in the fields of agriculture, food and medicine due to its unique properties and excellent biological activities. Polysaccharides, with excellent biocompatibility, good stability and various bioactivities, can be used for the preparation and functional modification of stable SeNPs with improved physicochemical and functional properties. This article focuses on the preparation, bioactivities and application of polysaccharide-SeNPs. It summarizes the methods and techniques used to synthesize polysaccharide-SeNPs through chemical reduction, analyzes the regulatory effect of polysaccharides on the physicochemical properties of SeNPs, and reviews the antioxidant, immunomodulatory and antitumor capacity of polysaccharide-SeNPs. Moreover, this paper describes the application of polysaccharide-SeNPs in food and other fields and discusses the challenges for the application of polysaccharide-SeNPs in food nutrition fortification. We believe that this review will provide a theoretical basis and a novel idea for the research and development of polysaccharide-SeNPs.

Raw almonds are rich in aldehydes, alcohols and other odorants contributing to fresh fruity and hay-like aromas. The flavor of almonds can change significantly due to various chemical reactions during thermal processing and storage, which can greatly affect its flavor quality. In this context, this review summarizes the major aroma compounds in raw almonds and the major aroma compounds formed by the Maillard reaction, the oxidation of fatty acids, and the degradation of amino acids and soluble sugars in roasted almonds, and it compares the effects of different thermal processing methods and conditions on the aroma compounds and aroma properties of almonds. In addition, this review summarizes the changes of the major aroma compounds and off-odor compounds in almonds during storage and the rational storage methods and conditions. Finally, possible future directions for research on almonds and other nuts are outlined. This review could provide a theoretical basis and reference for flavor quality control of almonds and other nuts during thermal processing and storage.

In nature, more than 90% of lycopene exists in all-trans form, but cis-lycopene in human blood and tissues accounts for more than 50% of total lycopene, and the proportion of cis-lycopene in prostate tissue was 90%. Numerous studies have shown that cis-lycopene has higher bioavailability than trans-lycopene, and thus has higher nutritional value and potential for development and utilization. Therefore, the properties and structures of lycopene isomers, the effect of extraction methods on the isomerization of lycopene, the types of isomerization (thermal isomerization, photoisomerization, etc.) and the physiological functions of cis-lycopene are reviewed in this paper. The mechanisms of different isomerization processes are expounded, and the advantages and disadvantages of each isomerization process are summarized. It is hoped that this review will provide a theoretical basis for further research on lycopene isomerization and provide scientific guidance for the production of lycopene with high proportion of cis-isomers.

In recent years, aerogels have received more and more attention from researchers due to their properties such as low density, high porosity, high specific surface area and low thermal conductivity. Polysaccharide-based aerogel is a solid porous nanomaterial with three-dimensional network structure prepared by using polysaccharide as the precursor material and transforming the liquid phase in the gel with gas phase through a drying method. In addition to the characteristics of traditional aerogel materials, polysaccharide-based aerogels also have the advantages of non-toxicity, easy availability of raw materials, biocompatibility and biodegradability. This article summarizes the preparation methods of polysaccharide-based aerogels, and reviews the properties and applications of different types of polysaccharide-based aerogels prepared with different precursor materials, so as to provide a reference for the research and application of polysaccharide-based aerogel materials in food packaging.

High-moisture extrusion technology has the characteristics of low energy consumption, green processing and high-efficiency production. Extruded products produced using plant proteins as the major raw material can be processed directly without rehydration for consumption, but have some problems such as poor texture, weak mouthfeel and flavor, so they require quality improvement. The current research on physicochemical changes during high-moisture extrusion has provided evidence that exogenous additives are useful for product quality improvement and innovations and can endow the product with more functional properties. This article reviews the research progress on modifiers for the quality improvement of high-moisture extruded plant protein products, outlines the classification and characteristics of plant proteins and modifiers, and summarizes the methods used to evaluate the product quality, with a focus on the role of modifiers in regulating the conformation, functional properties and quality of high-moisture extruded plant protein products, aiming to provide a reference for the quality control of high-moisture extruded products.

Portulaca oleracea is widely distributed around the world and has a long history of dual use in the fields of medicine and food. Its chemical constituents include flavonoids, polyphenols, terpenoids, sterols, coumarins, alkaloids, polysaccharides and organic acids, which make it have excellent antibacterial and antioxidant effects. More and more research has reported the antibacterial activity of Portulaca oleracea, which is significantly different on different bacteria, but a systematic review is lacking. In this paper, we summarize recent progress in research on the chemical composition, antimicrobial effect and mechanism of Portulaca oleracea in order to provide as a reference for the bioefficacy research, clinical application and product development of Portulaca oleracea.

Edible mushrooms are a group of large fungi for culinary and medicinal use. Edible mushrooms are rich in nutrients such as polysaccharides, proteins, and vitamins. Research has proven that edible mushroom polysaccharides have multiple biological activities including anticancer, hyperglycemic, and antioxidant activities. Furthermore, they can regulate the performance of starch in raw materials due to their structure characteristics as biomacromolecules. Currently, edible mushroom powders or purified polysaccharides from edible mushrooms have been introduced as ingredients to starch-based foods, which not only has a great impact on the sensory, textural, and nutritional qualities, but also endows products with new functionality. In this paper, recent progress in the application of edible mushroom polysaccharides for the improvement of starch properties and starchy food quality is reviewed. The effects of edible mushroom polysaccharides on starch solubility and swelling capacity, thermal properties, gelatinization properties, gelling properties and digestion characteristics are summarized. The application of edible mushroom polysaccharides in endowing new functionalities to starchy foods is outlined. We hope that this review could provide a reference for research on the enhancing effect of edible mushroom polysaccharides on starch functionality, and provide a new idea for the innovative development of functional starchy foods.

The fermentation process of traditional Baijiu Daqu involves extremely complex changes in microbial communities, and the microbial communities work collaboratively to determine the quality of Daqu. Analyzing the composition and functions of microbial community during Daqu fermentation is the key to revealing its fermentation mechanism, putting forward a rational control strategy and stabilizing the quality of Daqu. Therefore, microbial communities and functions have always been the focus of Daqu research. In this paper, the characteristics of microbial community structure in different types of Baijiu Daqu are summarized. The microbial sources involved in Daqu fermentation, the succession of microbial community and its driving factors, and the changes of microbial community during the storage period of Daqu are reviewed. The functions of microorganisms involved in Daqu fermentation are summarized. Finally, future research prospects are discussed. This review is expected to provide a reference for further research on the fermentation mechanism of Daqu.

Proteases have the advantages of high catalytic efficiency and strong specificity, which are widely used in food, chemical, medicine and other industrial fields. However, natural proteases are susceptible to environmental acidity and inappropriate environmental acidity reduces their catalytic efficiency. Effective strategies to improve the acidity resistance of enzymes are key to promote their industrial application. Rational design strategy is an effective technique to improve the acidic stability of enzymes, such as homologous sequence alignment, surface charge optimization, and intramolecular force optimization. Considering most foods and food raw materials which are subject to contamination by ochratoxin A (OTA) are acidic, this review summarizes the common strategies for improving the acidic stability of enzymes and their prospects for application in the field of OTA degradation. It is expected that this review will provide a reference for research on the acid resistance of industrial enzymes and provide a theoretical basis for the application of mycotoxin-degrading enzymes.

Grain and oil products, the most basic materials for human survival, are subject to various factors such as temperature, moisture, oxygen and microorganisms, triggering a series of biochemical reactions which can cause the generation of off-flavors such as sour and rancid odor. Clarifying the types and formation mechanism of rancid odor compounds and regulating them can help greatly improve the quality of grain and oil products. This article summarizes the key volatile compounds contributing to rancid odor produced during the storage and processing of grain and oil products, and clarifies their formation mechanisms from three aspects: lipid hydrolysis and oxidation, protein oxidative aggregation and the interaction between volatile and non-volatile compounds. Furthermore, the control measures to remove or mask the rancid odor are reviewed. The removal methods mainly include biological breeding and improvement, new storage and preservation technologies, traditional and emerging processing techniques and chemical methods; the masking methods include encapsulation technology based on host-guest interaction, aroma enhancement with exogenous enzymes and the addition of exogenous aroma enhancing ingredients. This paper can provide a theoretical reference and technical support for rancid odor control and flavor quality improvement of grain and oil products.

With the improvement of living standards and the change of dietary habits, metabolic syndrome has become a major global public health problem. The gut microbiota is one of the research hotspots in recent years. More and more studies have shown that the gut microbiota can conduct bidirectional signal transduction with different body tissues and organs such as the brain, liver and heart through various pathways, which is closely related to body health. Medium-chain fatty acids (MCFAs) exist in coconut oil, palm kernel oil and dairy products mainly in the form of medium-chain triglycerides (MCTs). MCFAs can be rapidly metabolized for energy in the body, and has good regulatory effects on glucose and lipid metabolism. This article reviews the effects of MCTs on gut microbes and their positive effects on metabolic syndrome in order to provide a reference for future research.