Probiotics offer numerous health benefits for human beings. However, it is difficult to achieve the expected beneficial effects of oral probiotics due to the viability loss during processing, storage and digestion. Oral delivery systems are effective ways to improve the processing and storage stability, gastric acid and bile salt tolerance, and intestinal adhesion and colonization ability of probiotics. This review focuses on the state of the art of oral delivery of probiotics, and summarizes the types of probiotics commonly used in probiotic products and their functional characteristics. Specifically, this review analyzes the effects of external environmental factors such as humidity, temperature, pH and oxygen, and internal environments such as the mouth, stomach, and small intestine on the survival rate of probiotics. Furthermore, the characteristics and applications of different oral delivery systems including microcapsule, hydrogel, oleogel, nanocoating, emulsion, and nanofiber are compared. Finally, this review proposes future prospects for cost reduction, intelligent packaging, co-packaging and population experiments of probiotic delivery systems, with the aim of providing technical support for the development of probiotic formulations with high storage stability and high viability suitable for intestinal targeted delivery.

This study utilized egg yolk peptide micellar nanoparticles (EYPNs), self-assembled from amphiphilic egg yolk peptides (EYPs), as a novel nanocarrier for improving the solubility and bioaccessibility of hydrophobic active compounds. EYPNs were dissociated by adjusting pH to 12.0 and mixed with the hydrophobic model compound curcumin (Cur), followed by a slow adjustment of pH to neutral pH to induce the re-assembly of EYPNs, which entrapped Cur to form stable EYPNs-Cur composite nanoparticles via hydrophobic interactions. Compared to free Cur, the solubility of encapsulated Cur increased largely, and even under light conditions, the encapsulated Cur remained stable almost without degradation for one month. In simulated gastrointestinal fluids, the bioaccessibility of Cur encapsulated in the composite nanoparticles was almost twice than that of free Cur. These results suggest that EYPNs can serve as stable nanocarriers for hydrophobic active compounds and improve their bioaccessibility.

The in vivo absorption of nanocarriers is a complex process, which is affected by the bioabsorption barrier. It is doubtful whether nanopreparations can promote the absorption and utilization of bioactive molecules. In this study, soy protein isolate (SPI) was used to prepare plant-based nanocarriers encapsulating β-carotene, and an in vitro digestion model was employed to investigate the structural changes of β-carotene loaded soy protein isolate nanoparticles (BC-SPIs) during digestion. Additionally, the Caco2 cell transport model was used to explore the impact mechanism of digestion conditions on the transmembrane transport of BC-SPIs after digestion. Furthermore, a Caco2-HT29 co-culture model containing a mucus layer was used to investigate the permeability of BC-SPIs through the mucus layer before and after digestion. This study found that before digestion, BC-SPIs could be directly absorbed by the Caco-2 cell monolayer through clathrin- and caveolin-dependent endocytosis. After in vitro simulated digestion, the size of BC-SPIs increased, and they could be directly absorbed by cells through clathrin-dependent endocytosis, caveolin-dependent endocytosis and macropinocytosis. The digested nanoparticles carried more negative charge, resulting in a 1.48-fold enhancement in the ability to cross the mucus layer and a 1.56-fold increase in the transmembrane transport efficiency of β-carotene. This study clarified the different absorption pathways of BC-SPIs before and after digestion and revealed the interaction between BC-SPIs and bile salts under simulated digestion conditions and the contribution of increasing the size of BC-SPIs to their transport and absorption efficiency by cells. These findings lay a theoretical foundation for further improving the application potential of nanocarriers in bioavailability enhancement, which will help advance the development of nanotechnology in several fields such as pharmaceuticals and health products.

Lipid phase composition of nanostructured lipid carriers (NLCs) modulates their digestive release behavior and cellular uptake by macrophage. In this study, the effects of the percentage of beeswax in the binary lipid mixture on the physical properties, lipid digestion, curcumin release, intestinal adhesion and penetration, and macrophage uptake of NLCs were investigated by in vivo simulated digestion, ex vivo intestinal adhesion and penetration and RAW264.7 mouse macrophage uptake experiments. The results showed that the particle size, loading efficiency and encapsulation efficiency of NLCs increased with an increase in the percentage of beeswax in the lipid phase. Compared with NLCs without beeswax (NLC0), whose oil phase consisted of medium chain fatty acid triglycerides (MCT), addition of 5% or 10% beeswax to MCT significantly improved the apparent viscosity, physical stability, intestinal mucosal adhesion and penetration of NLCs (the fluorescence signal intensity of curcumin in epithelial cells increased by 20.27% and 55.02%, respectively). Additionally, with an increase in beeswax content, the lipolysis efficiency, the release rate of free fatty acid (FFA) and the amount of released curcumin from NLCs decreased significantly; the release rate of FFA decreased in the following order: KNLC0 (0.13 min-1) > KNLC5 (0.08 min-1) > KNLC10 (0.06 min-1), and the amount of released curcumin declined in the following order: RNLC0 ((99.93 ± 0.09)%) > RNLC5 ((96.38 ± 0.05)%) > RNLC10 ((90.05 ± 0.05)%), indicating sustained release characteristics. Compared with free curcumin, NLCs promoted the enrichment of curcumin in RAW264.7 macrophages by 5.68–6.25 times. These findings can provide guidance for the application of beeswax based NLCs in oral delivery of lipophilic active ingredients and regulation of health effects.

To investigate the shelf life of eggs from different chicken breeds stored at various temperatures, Haugh unit, air cell depth, yolk index, albumen pH and mass loss of eggs from Jingfen 6 and Hy-Line Grey laying hens stored under refrigerated (4 ℃) or room temperature (25 ℃) conditions were examined. Taking Haugh unit below 60 as the end of shelf life, the shelf life of eggs from both breeds was found to be 12 and 83 days under ambient and refrigerated storage conditions, respectively. To develop prediction models for egg shelf life and storage time using back propagation artificial neural network (BP-ANN), Haugh unit, the most important indicator of egg freshness, was taken as an input parameter, and the other input parameters were selected based on the results of Pearson correlation analysis and used in descending order of correlation with Haugh unit. The specific input parameters were determined based on the performance of the models on the prediction set, and the BP-ANN models with optimized number of neurons in the hidden layer were compared with the other machine learning models partial least squares regression (PLSR) and support vector regression (SVR) models. The results showed that the BP-ANN models had higher accuracy in predicting the remaining shelf life and storage time of eggs compared to the PLSR and SVR models. This study provides a reference for determining the shelf life of eggs at different storage temperatures and technical support for the rapid, accurate and simultaneous prediction of the remaining shelf life and storage time.

This research investigated the relationship between mitochondrial damage and meat tenderness of Tan sheep during postmortem aging. The M. Longissimus dorsi muscles from six-month-old Tan sheep were divided into lipopolysaccharide (LPS) treatment and blank control groups. Mitochondrial reactive oxygen species (ROS) content, membrane potential, mitochondrial permeability transition pore (MPTP) openness, mitochondrial swelling, pH, cooking loss, texture, moisture distribution, shear force and myofibril fragmentation index (MFI) in each group were measured at 0, 6, 12, 24, and 72 hours postmortem. The results showed that during postmortem aging, MPTP openness gradually increased in both groups. ROS content, cooking loss rate and MFI value showed an increasing trend as well. Mitochondrial membrane potential, pH, elasticity, T22 peak area and shear force showed a decreasing trend. Hardness, chewability and cohesiveness increased at first and then decreased. Therefore, disruption of oxidative homeostasis in muscle cells of Tan sheep resulted in an increase of ROS content, which caused mitochondrial damage by inducing the opening of MPTP and decreasing mitochondrial membrane potential. Moreover, the structural changes of myofibrils shortened the gap between muscle protein molecules, resulting in increased water loss rate and poorer water retention in muscles, promoting the process of myofibril fragmentation and improving the tenderness of Tan sheep meat. Correlation analysis showed that mitochondrial damage and tenderization occurred simultaneously during the postmortem aging of Tan sheep meat, and the more serious the mitochondrial damage was, the better the tenderness was.

To explore how metal-binding antimicrobial peptide SIF4 kills foodborne Escherichia coli by targeting nucleic acid and protein in the cytoplasmic membrane without cytoplasmic membrane damage, the effect of SIF4 on intracellular nucleic acid biosynthesis was investigated, and fluorescence spectral analysis of the competition between SIF4 and ethidium bromide (EB) for binding to genomic DNA, ultraviolet (UV) spectral analysis of the interaction between SIF4 and genomic DNA, and the binding mode between SIF4 and genomic DNA were studied. Besides, the effect of SIF4 on intracellular protein biosynthesis was systematically evaluated. Results demonstrated that SIF4 could bind to E. coli genomic DNA through groove insertion and inhibit dose-dependently nucleic acid biosynthesis. Fluorescence spectral analysis showed that SIF4 could compete with EB for binding to genomic DNA through intercalation binding and electrostatic adsorption. UV spectroscopy showed that combination with SIF4 changed the molecular conformation of genomic DNA, but did not break its double strand structure. Circular dichroism (CD) spectroscopy showed that the base stacking force of genomic DNA was weakened, the double helix structure became loose, and the genomic DNA structure was changed from B to C configuration after combination with SIF4. In addition, SIF4 could significantly affect intracellular protein biosynthesis, and its inhibition effect was positively correlated with the treatment time and dose of SIF4. It is believed that SIF4 can enter the DNA groove through electrostatic adsorption or intercalation with genomic DNA, affecting DNA replication, RNA transcriptional biomass and protein translation to produce antimicrobial effect against Escherichia coli without cytoplasmic membrane damage. These results can provide support for the biocontrol of foodborne E. coli.

In this study, an ultrasound-assisted macroporous resin fixed-bed device was constructed for the purification of Aronia melanocarpa anthocyanins. Meanwhile, the effect of ultrasound on the mass transfer characteristics during the adsorption/desorption of anthocyanins on the fixed bed was investigated. The mass transfer patterns of total anthocyanins, total sugars, individual organic acids, individual anthocyaninic and non-anthocyaninic phenolics during fixed-bed purification were determined, and the effect of ultrasound on the physical properties of macroporous resins was analyzed. It was found that this fixed bed device could effectively remove impurities from the crude extract of A. melanocarpa. After purification, the purities of anthocyanin and polyphenol were 48.8% and 78.7%, respectively. During adsorption, ultrasound promoted the release of anthocyanins from the fixed bed. Specifically, in the fixed bed with a height of 2.5 cm, the breakthrough time of anthocyanin adsorption was reduced by 65.8% under sonication at 18.76 W/cm2. Moreover, the mass transfer during anthocyanin desorption using a highly polar eluent was enhanced by ultrasound. When 25% aqueous ethanol was used as the desorption solvent, the amount of anthocyanins desorbed from the fixed bed after 48 min of elution was increased by 12.6% by 18.76 W/cm2 ultrasound. Besides, ultrasound significantly increased the surface roughness of macroporous resin particles, but did not change the interior structure. In summary, ultrasound-assisted fixed bed treatment significantly improves the flowing of anthocyanins among resin particles during the adsorption/desorption, but has little effect on the interaction between single resin particles and anthocyanins.

In order to develop special liquid egg yolk for making of egg tart, the effects of ultrasound-assisted chitosan treatment on the emulsification properties of liquid egg yolk and structure of egg yolk proteins were investigated in this study. The emulsification properties of fresh egg yolk, egg yolk added with chitosan, heated egg yolk, heated egg yolk added with chitosan, ultrasound-treated egg yolk and ultrasound-assisted egg yolk added with chitosan were evaluated by measuring emulsifying activity, emulsion stability and particle size, as well as microscopic observation. Egg yolk protein structure was characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), Fourier transform infrared (FTIR) spectroscopy, and fluorescence spectroscopy. The results showed that compared with the untreated samples, ultrasound-assisted chitosan treatment increased the emulsifying activity of liquid egg yolk by 29.51% and the emulsion stability by 9.47%, decreased the particle size by 50.01% and the interfacial tension by 16.67%, and smoothened the interfacial tension curve. The combined treatment reduced the size of emulsion droplets and increased the dispersivity of egg yolk particles as observed by scanning electron microscopy (SEM). The intensity of protein bands in SDS-PAGE was decreased after the combined treatment, which resulted in protein unfolding and exposure of hydrophobic amino acid residues and increased the surface hydrophobicity of liquid egg yolk increased by 12.91%. Moreover, the relative contents of α-structures and β-structures in proteins were reduced after the treatment and the relative content of random coil was increased by 5.26%, indicating that ultrasonic-assisted chitosan treatment led to more disordered and loose protein structure, and the increase of hydrophobicity could promote the emulsifying properties. In summary, this study demonstrates the great potential of ultrasound-assisted chitosan treatment to enhance the emulsification properties of liquid egg yolk for baking purpose.

To investigate the effects of ultrasound treatment combined with pH adjustment on the gelling properties of composite gels prepared from ginkgo seed protein isolate (GSPI) and whey protein isolate (WPI), the physicochemical properties and molecular behavior of the GSPI and WPI mixture and the texture, water-holding capacity (WHC) and microstructure of the heat-induced gel of the protein mixture were characterized. Results showed that ultrasonic treatment at 25%, 45%, or 65% power alone did not significantly influence protein solubility. However, ultrasonic treatment combined with lower pH (pH 4.0) markedly decreased protein hydrophobicity, and increased surface sulfhydryl group content and the sol’s particle size. The results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Fourier transform infrared (FTIR) spectroscopy showed that ultrasonic treatment affected protein structure and aggregation behavior. The heat-induced composite gel formed at lower pH had poor textural properties, whereas the composite gel formed at higher pH (especially at pH 5.0) exhibited improved textural properties and higher WHC. The textural properties and WHC of the composite protein gel were significantly improved with increasing ultrasonic power, which was attributed to the fact that ultrasonic treatment strengthened the interaction between hydroxyl groups in GSPI and WPI, promoting protein aggregation and cross-linking and improving the structural compactness of the composite gel. Overall, ultrasound treatment combined with pH adjustment could be an effective method for improving the functional properties of the composite protein gel.

In order to find an excellent drying method for Panax notoginseng leaves (PNL), PNL were dried by using hot air drying (HAD), heat pump drying (HPD) or vacuum drying (VD). The contents of total saponins, polysaccharides, total phenols, total flavonoids, and monomer saponins, in vitro antioxidant activity and α-glucosidase inhibitory capacity of fresh and dried PNL were determined. By using gas chromatography-ion mobility spectrometry (GC-IMS) and non-targeted metabolomics, the volatile components and metabolites in fresh and dried PNL were identified and analyzed, respectively. The results showed that all three drying methods could significantly increase the contents of total saponins and polysaccharides in PNL, reduce the contents of total phenols and total flavonoids, but decrease the functional activities of PNL to varying degrees. Among the four samples, the HPD dried sample had the highest contents of total saponins and polysaccharides, the strongest 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity and α-glucosidase inhibitory capacity, and moderately strong 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radical scavenging capacity and ferric ion reducing antioxidant power (FRAP). High-performance liquid chromatography (HPLC) analysis showed that HPD treatment significantly reduced the contents of notoginsenosides Fc and Fe, while VD treatment showed the opposite effect. A total of 85 volatile components were detected, and the HPD dried sample showed the highest relative contents of alcohols and aldehydes, and the lowest relative content of ketones. In addition, there were significant differences between treatment groups. Furthermore, ultra-high performance liquid chromatography-quadrupole-orbitrap mass spectrometry (UPLC-Q-OT-MS) identified 659 metabolites in the fresh and HPD dried samples. In the positive and negative ion modes, 113 and 68 metabolites were significantly up-regulated, and 98 and 31 metabolites were significantly down-regulated, respectively. These differential metabolites predominately included lipids, lipid-like molecules, organic heterocyclic compounds, organic acids and their derivatives. Out of the 24 saponins in PNL, seven were significantly down-regulated and one was significantly up-regulated, which verified the HPLC results. Through the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of differential metabolites, it was found that the most likely metabolic pathways in HPD dried PNL included the biosynthesis of amino acids, 2-oxycarboxylic acid metabolism, and the biosynthesis of cofactors. In conclusion, HPD provided the best preservation of the chemical composition and functional activities of PNL, making it more suitable for drying PNL. Through multiple metabolite pathways, HPD could alter the composition of metabolites in PNL and affect its volatile components.

In order to investigate the effects of thermal processing methods on the quality and oxidation characteristics of pork, boiled, microwaved, roasted, or deep-fried pork loin was evaluated for quality indicators such as cooking loss, color, shear force, texture, basic chemical composition, odor and taste and oxidation indicators such as protein carbonyl content and thiobarbituric acid reactive substance (TBARS) value. The results showed that compared with the control group (raw pork), the quality and oxidation characteristics of cooked pork samples were significantly different. The decreasing order of cooking loss rate during different thermal treatments was roasting > microwave > deep-frying > boiling; protein and ash contents were positively correlated with cooking loss, while water content was negatively correlated with cooking loss. The most significant color changes were found in deep-fried pork, whose elasticity, cohesiveness and shear force were significantly different compared with the other treated groups. Protein carbonyl content was significantly higher in microwaved pork than the other treated groups (P < 0.05). Roasted pork exhibited the highest TBARS value. Electronic nose results showed an increase in the content of volatile flavor substances after thermal processing, and electronic tongue results indicated that the umami intensity of deep-fried pork was the highest. The results of this study can provide reference for the selection of pork thermal processing methods.

Objective: The purpose of this study was to optimize the roasting process for Xinjiang Nang pit-roasted lamb meat and explore the effects of variable-temperature roasting on the roasting loss percentage, color, tenderness, and heterocyclic aromatic amine (HAA) and polycyclic aromatic hydrocarbon (PAH) contents of roasted lamb meat. Methods: The three-stage variable-temperature roasting process involving high temperature (T1), roasting time (t1), medium temperature (T2), roasting time (t2), low temperature (T3), and roasting time (t3) was optimized using an L27 (36) orthogonal array design and fuzzy mathematics comprehensive evaluation method. The differences in the contents of HAAs and PAHs in lamb meat roasted at variable temperature (CK), high temperature (HT) and low temperature (LT) were analyzed. Results: The decreasing order of the influence of variable-temperature roasting parameters on the sensory evaluation of roasted lamb meat was as follows: T1 > t2 > T2 > t1 > t3 > T3. The optimal roasting parameters were T1 = 300 ℃, t1 = 4 min, T2 = 220 ℃, t2 = 6 min, T3 = 100 ℃, t3 = 7 min, and the sensory score of lamb meat roasted under these conditions was 3.408 out of 4 points. There was a significant positive correlation between roasting loss percentage and T2 (r = 0.50), between shearing force and T1 (r = 0.47), between internal L* value and t1 (r = 0.57), between surface a* value and sensory evaluation (r = 0.64), and between surface b* value and roasting loss percentage (r = 0.40). The total content of HAAs in roasted lamb meat was in decreasing order of HT > LT > CK. The highest roasting temperature in the CK group was the same as that in the HT group, but the total content of HAAs in the CK group was significantly lower than that in the HT group (P < 0.05). There was no significant difference in the total amount of HAAs between the LT and CK groups (P > 0.05). Principal component analysis of the total amounts of HAAs in the HT, LT and CK groups showed that the substances with the highest contribution rate to the first principal component (PC1) were 2-amino-3,4-dimethylimidazo[4,5-ƒ]quinolone (MeIQ), 2-amino-3-methylimidazo[4,5-ƒ]quinoxaline (IQx) and 2-amino-3,7,8-trimethylimidazo[4,5-ƒ]quinoxaline (7,8-DiMeIQx), respectively. The total content of PAHs in the HT group was (427.45 ± 27.84) ng/g, which was significantly higher than that in the LT and CK groups (P < 0.05). The substances with the largest contribution rate to PC1 and the second principal component (PC2) were phenanthrene (Phe) and benz[a]anthracene (BaA) for the LT group, respectively, and the substance with the largest contribution rate to PC1 were BaA for the CK group. Conclusion: High-temperature roasting temperature is the key factor affecting the eating quality of lamb meat roasted at variable temperature, and variable-temperature roasting effectively reduces the total content of HAAs and PAHs in roasted lamb meat.

Objective: To investigate the molecular mechanism underlying the protective effect of Solanum tuberosum anthocyanin (STA) on radiation-induced hematopoietic stem/progenitor cell senescence. Methods: C57BL/6 mice were randomly divided into three groups: control, model, STA treatment and STA prevention, and the cell senescence model was constructed by X-ray irradiation. The hemogram of mice in each group were examined using a hematology analyzer after drug administration. Stem cell antigen 1 positive hematopoietic stem/progenitor cells (Sca-1+HSC/HPCs) were isolated and purified from each group by immunomagnetic cell sorting and were stained using a senescence-associated β-galactosidase (SA-β-Gal) kit to calculate the proportion of SA-β-Gal positive cells. The number of mixed lineage colony forming unit (CFU-Mix) was used to evaluate the colony-forming capacity and differentiation potential of hematopoietic stem/progenitor cells. Cell cycle was analyzed by flow cytometry. The mRNA and protein expression of p53 and p21Waf1/Cip1 were detected by quantitative real-time polymerase chain reaction (qPCR) and Western blot. Results: The numbers of red blood cells (RBCs), white blood cells (WBCs) and platelets in the peripheral blood were significantly lower in the model group than in the control group (P < 0.01). In addition, compared with the control group, the proportion of SA-β-Gal positive cells significantly increased (P < 0.01), the number of CFU-Mix significantly fell (P < 0.01), the proportion of G0/G1 phase cells significantly increased, the proportions of G2/M and S phase cells significantly dropped (P < 0.01), and the relative mRNA and protein expression levels of p53 and p21Waf1/Cip1 significantly increased in the model group (P < 0.01). STA could significantly restore the above parameters of mice in the model group irrespective of whether it was administered before or after X-ray radiation, with more pronounced effect being observed in the former case. Conclusion: STA can protect hematopoietic stem/progenitor cells against radiation by regulating the p53-p21Waf1/Cip1 pathway.

In order to investigate the effect of Laminaria japonica polysaccharide WLP5, obtained by hot water extraction, on immune function and the growth of tumor in MCF-7 breast cancer cell-bearing mice, MCF-7 tumor-bearing nude mice were randomly divided into four groups (n = 10 each): model, positive control (doxorubicin hydrochloride, 0.4 μg/kg mb), low-dose (50 μg/kg mb) and high-dose (200 μg/kg mb) WLP5. All mice were treated by intragastric administration every other day for 50 days. The long and short diameters of tumor, tumor volume, tumor inhibition rate, hematological indicators and the concentrations of serum cytokines including interleukin-2 (IL-2), IL-6, transforming growth factor-β (TGF-β) and tumor necrosis factor-α (TNF-α) were determined and pathological changes of liver and tumor sections from mice in each group were observed. The results showed that the long diameter, short diameter and volume of tumor in the low- and high-dose WLP5 groups significantly decreased in comparison to the model group (P < 0.05 or P < 0.01), and the tumor inhibition rates were 36.5% and 48.9%, respectively. Compared with the model group, monocyte percentage significantly decreased (P < 0.05) and mean platelet volume significantly increased in the high-dose group (P < 0.05), but no significant differences were found in any other hematological indicators. Moreover, WLP5 at low and high doses significantly increased the release of IL-2 and IL-6 (P < 0.05 or P < 0.01). The results of pathological sections suggested that the liver tissue of mice in the high-dose group was complete, while the tumor cells showed large areas of necrosis and the nuclei disappeared, indicating that WLP5 has strong antitumor effect in vivo without obvious toxicity to normal cells or tissues. The antitumor activity of WLP5 is related to the regulation of immune function.

This study was undertaken in order to study the effect of olive oil rich in hydroxyl tyrosol (OHT) on blood glucose and lipids in hyperlipidemic mice. Mice with hyperglycemia and hyperlipidemia induced by intragastric administration of lipid emulsion and 75% egg yolk in water were randomly divided into six groups: hyperlipidemia model, OHT at high, middle and low dosages (200, 100, and 50 mg/kg mb), olive oil (OL) and philbert (PL) as a positive control. Normal mice given normal saline was used as a control group. After continuous administration for 28 days, the effect of OHT on fasting blood glucose (FBG), glycated hemoglobin (HbAlc), total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), total bilirubin (TBIL), total bile acid (TBA), alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-ammonia acyltransferase (GGT) and alkaline phosphatase (ALP) in mice in each group were analyzed, and the acute and chronic toxicity of OHT was evaluated. The results showed that compared to the model group, OHT effectively decreased the levels of FBG, HbAlc, TC, TG, LDL, TBIL and TBA, increased the level of HDL, and inhibited the activities of ALT, AST, GGT and ALP. It significantly improved glucose and lipid metabolic disorders, and reduced body mass in a dose-dependent fashion. OHT had no acute or chronic toxicity to normal mice and could significantly increase the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in the serum, reduce the level of malondialdehyde (MDA), improve the antioxidant capacity, and control the body mass of mice. In summary, OHT has hypoglycemic and lipid-lowering effects in hyperlipidemic mice, and is non-toxic. This study can provide a reference for the development of lipid-lowering products using olive oil.

The release characteristics of γ-aminobutyric acid (GABA) from the fruits of ‘Nongda 4’, ‘Nongda 7’ and ‘Yanshan 2’ Cerasus humilis (Bge.) Sok were studied during in vitro simulated digestion and ‘Nongda 4’ C. humilis (Bge.) Sok, with the highest GABA content, was selected to evaluate the improving effect of its fruit pulp on sleep behavior in mice by acute toxicity test, elevated cross maze test, pentobarbital sodium-indued immediate sleep test, prolonged sleep duration test, and sodium barbiturate-induced sleep latency test. The results showed that oral administration of 800 mg/kg mb C. humilis (Bge.) Sok. fruit pulp could significantly prolong the sleep duration of mice with insomnia (P < 0.05), increase the sleep rate, and shorten the sleep latency. The ameliorative effect may be related to down-regulating the levels of proinflammatory factors and regulating the function of the hypothalamic-pituitary-adrenal axis.

Adenosine triphosphate (ATP) treatment effects on the quality maintenance of fresh-cut cucumber and the contents of bioactive compounds such as total phenolic and γ-aminobutyric acid (GABA) in fresh-cut cucumber were studied. Fresh-cut cucumber was soaked separately in 0, 0.8, 1.2, 1.6 and 2.0 mmol/L ATP solution for 10 min. To determine the appropriate concentration of ATP treatment, fruit quality parameters, and total phenol and GABA contents were measured during storage at 10 ℃ for 72 h. Furthermore, the regulatory mechanism of ATP treatment at the appropriate concentration on total phenol and GABA accumulation. The results indicated that compared with the control group, ATP treatment maintained better color quality and lower total bacterial count (TBC), delayed the decrease in firmness and ascorbic acid content, and promoted an increase in the accumulation of total phenols and GABA in fresh-cut cucumber, the effect being most pronounced at an ATP concentration of 1.6 mmol/L. Furthermore, compared with the control group, 1.6 mmol/L ATP treatment increased the activities of phenylalanine ammonia-lyase (PAL), 4-coumarate-CoA ligase (4CL), cinnamate-4-hydroxylase (C4H), glutamate decarboxylase (GAD), diamine oxidase (DAO), polyamine oxidase (PAO) and 4-amino aldehyde dehydrogenase (AMADH), and promoted the synthesis of phenolic substances and the decomposition of glutamate (Glu) and polyamine to produce GABA, thus increasing total phenol and GABA contents in fresh-cut cucumber. These results indicated that ATP treatment could not only delay quality deterioration, but also increase total phenol and GABA contents, thereby improving the antioxidant capacity and nutritional value of fresh-cut cucumber.

This study was conducted in order to explore the effect of exogenous glucose treatment on postharvest cold resistance and sugar metabolism in apricot fruit. Xinjiang-grown ‘Saimati’ apricots were subjected to vacuum osmosis treatment with different concentrations of glucose followed by cold storage at (0 ± 1) ℃ for 49 days. The incidence of chilling injury, chilling injury index, quality and sugar metabolism-related indicators of apricot fruit were measured at regular intervals during the storage period. The results showed that 200 mmol/L exogenous glucose treatment could effectively inhibit the increase in the incidence of chilling injury, chilling injury index, cell membrane permeability and the accumulation of malondialdehyde (MDA), and well maintain the hardness, color, soluble solids content (SSC), titratable acid (TA) and ascorbic acid (ASA) contents of apricot fruit. Meanwhile, compared with the control group, the exogenous glucose treatment increased the activities of acid invertase (AI), neutral invertase (NI), sucrose phosphate synthase (SPS) and sucrose synthase (SS) in apricot fruit, and significantly increased the accumulation of glucose and fructose during storage. However, the content of sucrose decreased during the mid-to-late stage of storage (21–49 days). In summary, exogenous glucose treatment could enhance the contents of glucose and fructose by regulating the activity of enzymes related to sugar metabolism, thereby enhancing cold resistance and maintaining the storage quality of the fruit. The results of this study can provide a reference for controlling chilling injury in postharvest apricot fruit.

Peaches are subject to flesh softening during postharvest storage and transport, which affects the storage life of the fruit and causes huge economic losses. Previous research has demonstrated that postharvest brassinolide treatment can maintain flesh firmness, ascorbic acid and soluble solids contents, and enhance disease resistance in peach fruits. This study assessed the influence of postharvest brassinolide treatment on the expression of key genes involved in cell wall degradation and the phenylpropanoid pathway in peach fruits by real-time fluorescence quantitative polymerase chain reaction (qPCR). The results showed that brassinolide dipping inhibited the gene expression of pectate lyase 1, polygalacturonase 21 and pectin methylesterase 1, and significantly enhanced the gene expression of peroxidase, cinnamoyl-CoA reductase, phenylalanine ammonia lyase and caffeoyl-CoA-O-methyltransferase 5 in peach fruits. It also increased the gene expression levels of chaleone synthase, chaleone isomerase, dihydroflavonol-4-reductase and flavanone 3-hydroxylase at the early stage of storage. These findings imply that brassinolide can suppress the expression of key genes involved in cell wall degradation and enhance the expression of key genes involved in the phenylpropanoid pathway, thereby delaying peach fruit softening and enhancing disease resistance.

The effect of treatment with 5 g/L chitosan (CTS), 100 μmol/L melatonin (MT) and their combination on the storage quality and chlorophyll metabolism of fresh-cut broccoli (Brassica oleracea L. var. italica Planch.) during storage at (15 ± 1) ℃ and relative humidity (RH) of 85%–90% were investigated through sensory evaluation, physiological and biochemical characterization, and texture analysis. The results showed that separate and combined treatment with CTS and MT effectively maintained the sensory quality of fresh-cut broccoli, and the sensory scores of the samples treated with CTS, MT and their combination were 3.36, 2.83 and 5.17 times higher than that of the control group on the 7th day of storage, respectively. Compared with the control group, the combined treatment could significantly inhibit the activity of chlorophyll-degrading enzymes in broccoli (P < 0.05), thereby inhibiting chlorophyll degradation, while significantly reducing the rate of mass loss and respiratory intensity of fresh-cut broccoli (P < 0.05). Furthermore, it was found that the combined treatment increased chlorophyll content by 83.80%, reduced chlorophyllase (CLH), Mg-dechelatase (MDcase), pheophyllase (PPH) and pheophyllase a oxygenase (PAO) activities by 5.78%, 26.76%, 18.59% and 34.87%, respectively, and decreased mass loss rate and respiratory intensity by 24.82% and 45.28%, respectively on the 5th day of storage. Also, the combined treatment better maintained the texture properties of fresh-cut broccoli, such as hardness and chewiness, as well as the contents of soluble solids, soluble protein, total phenols and flavonoids. These findings suggest that combined treatment with CTS and MT can effectively delay the yellowing and maintain the quality of fresh-cut broccoli.

Lipid oxidation is an important factor causing the quality deterioration of egg yolk powder. In this study, the lipid oxidation process of egg yolk powder was monitored during accelerated storage at 40, 50 or 60 ℃, and a shelf life prediction model was developed and applied to predict the shelf life of egg yolk powder at 25 ℃. The results showed that the acid value (AV), peroxide value (PV), thiobarbituric acid-reactive substances (TBARS) value, p-anisidine value (p-AV) and total oxidation value (TOTOX) of egg yolk powder increased, and the L*, a* and b* values, sensory quality and nutritional value decreased during accelerated storage at all temperatures. The changes of fatty acids in egg yolk powder were analyzed by gas chromatography-mass spectrometry (GC-MS). The relative contents of polyunsaturated fatty acid (PUFA) and monounsaturated fatty acid (MUFA) were found to significantly decrease, while the relative content of saturated fatty acid (SFA) significantly increased after accelerated storage for 35 days compared to fresh egg yolk lipids (P < 0.05). Using Fourier transform infrared (FTIR) spectroscopy, it was found that the structure of lipids in egg yolk powder did not change significantly during accelerated storage, but the intensity of the characteristic absorption peaks changed slightly, which was related to the lipid oxidation of egg yolk powder. Pearson correlation coefficient showed that among all quality indicators, the highest correlation was found between the PV and sensory score of egg yolk powder, so PV can be used as a key indicator of the kinetics of quality deterioration. Kinetic model analysis showed that the change of PV of egg yolk powder was better fitted to a zero-order kinetic model. Based on the Arrhenius equation, the activation energy EA was 19.58 kJ/mol and the pre-exponential factor k2 was 83.93. The predicted shelf life of egg yolk powder was 580 days when stored at 25 ℃, and the relative error between the predicted and actual shelf life was −7.15%. This indicates that the established prediction model could accurately the shelf life of egg yolk powder.

In this study, diatomite was used as an effective carrier for carvacrol to prepare an antibacterial complex, which was further incorporated into gelatin solution to obtain active composite films. The effect of the addition of the complex on the physical properties and antibacterial activity of gelatin based composite films was investigated. The results of scanning electron microscopy (SEM) and infrared spectroscopy showed that carvacrol was successfully adsorbed to the pores and surface of diatomite. With increasing content of the complex, the thickness, elongation at break, water vapor permeability, oxygen permeability, antioxidant activity and antibacterial activity increased, whereas the light transmission, moisture content, water solubility and tensile strength of the films decreased. Overall, the film with the complex added at 20% showed good performance, whose tensile strength and elongation at break were 15.13 MPa and 67.43%, respectively. The film scavenged 56.33% of 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical, and the inhibition zone diameter of the film against Staphylococcus aureus and Escherichia coli was 39.4 and 23.7 mm, respectively. More importantly, the gelatin film containing diatomite/carvacrol complex exhibited a much slower release rate of carvacrol and longer-acting antibacterial activity than the film containing the same content of carvacrol. These experimental results provide theoretical guidance and an experimental reference for using diatomite to carry carvacrol in developing antibacterial gelatin films with sustained release properties.

The aim of the study was to investigate the appropriate postharvest storage temperature for Pouteria caimito Radlk., to prolong its storage life, and more broadly to expand the market for Pouteria caimito. The effects of different storage temperatures on the postharvest physiology and storage quality of P. caimito were studied by determining the main quality indices and physiological indices of fruit samples stored at 5, 10, 15 or 20 ℃ after harvest. The results showed that cold storage could maintain the quality of P. caimito to a certain extent, but chilling injury (CI) symptoms, characterized by pitting and water-soaked appearance of the fruit surface and peel browning, appeared after three days of storage at 5 ℃. Compared with the other three storage temperatures, storage at 10 ℃ could maintain higher levels of fruit hardness, total soluble solids (TSS), vitamin C (VC) and total sugar, and lower respiratory intensity and cell membrane permeability. Compared with 20 ℃, storage at 10 ℃ could inhibit the increase of malondialdehyde (MDA) content, peroxidase (POD) and polyphenol oxidase (PPO) activity, thereby delaying the senescence and browning of P. caimito. Therefore, 10 ℃ was the appropriate storage temperature for P. caimito. The results of this study will provide a theoretical basis for postharvest quality maintenance of P. caimito.

Cold storage is one of the most commonly used ways to store pomegranates (Punica granatum L.). Husk browning can occur during cold storage due to phenolic metabolism and energy decay. Three pomegranate cultivars grown in Shaanxi: the introduced cultivar ‘Tunisia soft seed’, the traditional cultivar ‘Jingpitian’ and the newly bred cultivar ‘Lishanhong’ were used to explore the relationship between husk browning and phenolic and energy metabolism under storage conditions of (4.0 ± 0.5) ℃ and 85%–90% relative humidity, and the storage characteristics of these cultivars were compared. The results showed that with the extension of storage time, browning index increased, 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging capacity increased at first and decreased later, 2,2’-azino-bis-3-ethylbenzothiazoline 6-sulfonic acid (ABTS) cation radical scavenging capacity, total phenol and flavonoid contents fluctuated only slightly, and anthocyanin content increased at first and then decreased for all cultivars. Among them, the contents of total phenols, total flavonoids and anthocyanins were highest in ‘Tunisia soft seed’ pomegranates. During storage, polyphenol oxidase (PPO) activity remained lowest, and phenylalanine ammonialyase (PAL) activity remained highest in ‘Tunisia soft seed’ pomegranates. Peroxidase (POD) activity was always highest in ‘Jingpitian’ pomegranates. In addition, ‘Tunisia soft seed’ pomegranate husk maintained higher adenosine triphosphate (ATP) and adenosine diphosphate (ADP) contents and energy charge, as well as higher Mg2+-ATPase and H+-ATPase activities during storage. The correlation analysis showed that the browning index of ‘Jingpitian’ pomegranate husk, which was highest among the three cultivars, was significantly positively correlated with total phenol and flavonoid contents, POD and PAL activities, and ATP and ADP contents (P < 0.05 and P < 0.01); the browning index of ‘Tunisia soft seed’ pomegranate husk, which was lowest, was significantly positively correlated with POD activity and the content of adenosine monophosphate (AMP) (P < 0.01); and the browning index of ‘Lishanhong’ pomegranate husk, which was in the middle, was significantly positively correlated with total phenol and AMP contents (P < 0.05 and P < 0.01, respectively) but significantly negatively correlated with Mg2+-ATPase activity (P < 0.01). Principal component analysis (PCA) showed significant quality differences between ‘Tunisia soft seed’ pomegranates and the two other cultivars. The above findings demonstrated that the browning degree of pomegranate husk under cold storage conditions varied among cultivars and was related to phenolic and energy metabolism.

In this study, we monitored changes in fruit hardness, cell wall-modifying enzyme activities such as polygalacturonase (PG), pectin methylesterase (PME), pectin lyases (PL) and β-galactosidase (β-Gal), and physiochemical properties of three cell wall polysaccharides including water soluble polysaccharide (WSP), trans-1,2-cyclohexanediaminetetraacetic acid (CDTA)-soluble polysaccharide (CSP) and Na2CO3-soluble polysaccharide (NSP) in ‘Yate’ kiwifruits during postharvest cold storage. Results showed that postharvest kiwifruits went through a ‘fast-slow’ softening process. PG activity showed a maximum value of 670.76 U/mg after 10 days of storage. PL and PME activities showed a maximum increase over the first five days of storage, reaching up to 3.41 and 9.17 U/mg, respectively. Particularly, β-Gal activity continuously increased during storage and showed a negative correlation with fruit hardness (r = −0.888). The pectin contents of WSP, CSP and NSP increased significantly with storage time. Moreover, the results of high performance gel permeation chromatography (GPC) showed that the weight average molecular mass of WSP increased, that of CSP initially decreased and then increased, and that of NSP gradually decreased during storage. Furthermore, a decrease in the area and an increase in the lamellarity of WSP were observed by scanning electron microscopy (SEM), whereas CSP was found to be soft and muslin-like after 15 days of storage, and the cluster-like accumulation of NSP was gradually dispersed with more debris being observed. These results may provide a solid theoretical basis for elucidating the exact mechanism of kiwifruit softening.

In an attempt to evaluate the effect of eugenol on the preservation and quality of passion fruit, its physiological and biochemical changes were investigated after soaking treatment with 0.3 mg/mL at room temperature, (20 ± 1) ℃. The results showed that eugenol treatment reduced the postharvest respiratory rate, mass loss rate, shrinkage index and cell membrane permeability, inhibited the accumulation of malondialdehyde (MDA), superoxide anion radical and hydrogen peroxide, slowed down the decrease in the contents of soluble solids, soluble proteins, total phenols and flavonoids and maintained high contents of endogenous antioxidant substances such as reduced ascorbic acid (AsA) and reduced glutathione (GSH) in passion fruit. It also maintained high scavenging capacity against 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical, 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation and ferric reducing capacity, and improved the activities of antioxidant enzymes such as catalase (CAT), superoxide dismutase (SOD), and ascorbate peroxidase (APX). In summary, eugenol treatment can maintain high quality and antioxidant activity of postharvest passion fruit, thereby delaying fruit senescence and extending the storage period.

In this study, commercial films with different permeabilities (polyvinylidene chloride (PVDC), BXD3C, BXD4C and CRM1C) were selected for packaging treatment of postharvest Agaricus bisporus to investigate the changes in the storage quality and respiratory metabolism of Agaricus bisporus at 4 ℃. The results showed that CRM1C had the greatest permeability among the four films, BXD3C and BXD4C were in the middle, and the permeability of PVDC was worst. On the 15th day of storage, compared with BXD3C, BXD4C, and PVDC packaging, CRM1C packaging could effectively inhibit the respiration rate of postharvest Agaricus bisporus, reduce malondialdehyde (MDA) accumulation and intracellular electrolyte leakage, maintain vitamin C content, and inhibit the increase of browning index. Meanwhile, CRM1C packaging could maintain the activities of rate-limiting enzymes in glycolysis (pyruvate kinase (PK) and phosphofructokinase (PFK)), the tricarboxylic acid cycle and the electron transport chain (α-ketoglutarate dehydrogenase (α-KGDH) and succinate dehydrogenase (SDH)) as well as cellular energy charge in Agaricus bisporus, and increase the activity of adenosine triphosphate (ATP) synthase, ensuring energy supply in Agaricus bisporus in the late storage period and delaying postharvest browning. The results of this study can provide a reference for the post-harvest preservation of Agaricus bisporus.

Foodborne pathogens are a major threat to human health. The aim of this study was to investigate the inactivating effect of chitosan (Chi) combined with photodynamic treatment (Chi-PDT) mediated by curcumin (Cur) on pathogens. After determining minimal inhibitory concentration of Chi, we compared the bactericidal effects of PDT and Chi-PDT, and evaluated the influence of curcumin concentration and illumination time on the inactivating effect of Chi-PDT against Staphylococcus aureus, Bacillus cereus, Escherichia coli and Salmonella Typhimurium. The mechanism for the synergistic bactericidal effect of Chi and PDT, the inactivating effect of Chi-PDT on pathogen cocktails and Salmonella on the surface of cherry tomatoes and the impact of Chi-PDT on the quality of cherry tomatoes were assessed. The results showed that chitosan could augment the inactivating effect of PDT by enhancing the interaction between bacteria and Cur. The sterilization effect of Chi-PDT was dependent on Cur concentration and illumination time. Moreover, 20 min illumination after treatment with 0.05% chitosan combined with 15 μmol/L curcumin reduced the counts of S. aureus and B. cereus by 7.90 and 7.60 (lg (CFU/mL)), respectively. However, for E. coli and Salmonella, similar effects required treatment with 0.05% Chi plus 100 μmol/L Cur and 0.05% Chi plus 25 μmol/L Cur, respectively. Chi-PDT reduced the total count of the quaternary bacterial mixture by 6.00 (lg (CFU/mL)), which was 5.09 (lg (CFU/mL)) higher than that with PDT alone. These results showed that Chi-PDT had a better bactericidal effect against both individual and mixed bacteria than PDT. The count of Salmonella on the surface of cherry tomatoes was reduced by 1.62 (lg (CFU/fruit)) by Chi-PDT. Chi-Cur coating combined with PDT treatment inhibited bacterial growth on cherry tomatoes during storage without affecting the color, firmness or mass loss. Thus, Chi-Cur coating combined with PDT treatment has great potential for application in the fields of food sterilization and fruit and vegetable preservation.

In order to explore the structure and dynamic changes of fungal communities in melon fruit during storage, the internal transcribed spacer (ITS) region of fungi in melon peel and pulp stored for 0, 7, 14, or 21 d was sequenced using Illumina MiSeq high-throughput sequencing technology. Species annotation and species composition analysis were used to determine the dominant fungal communities in the fruit tissues at each storage time point. The results showed that Vishniacozyma, Papiliotrema, and Metarhizium were dominant in the peel on day 0, while Aspergillus, Trichothecium, and Penicillium became dominant as storage time increased. The dominant fungal communities in the flesh also changed as storage time increased, with Vishniacozyma, Trichothecium, and Pichia being the dominant fungi on the 21th day of storage. Diversity analysis showed that fungal abundance and diversity were higher in the peel than in the flesh. In summary, the abundance and diversity of fungal communities in melon tissues changed significantly during storage, and the interaction of pathogenic fungi such as Aspergillus, Trichothecium, and Penicillium resulted in deterioration of melon fruit quality. This study provides a theoretical basis for the development of preservation methods and biological control strategies for melons in the future.

An intelligent indicator film was prepared with chitosan (CS) and sodium alginate (SA) as film-forming material with added black apple peel anthocyanin (BAA). The effects of different concentrations of BAA on the microstructure, thickness, color, mechanical properties, moisture content, and ultraviolet (UV) transmittance of the composite film were analyzed and compared. In addition, the feasibility of applying the composite film for monitoring shrimp freshness was studied. The results showed that addition of BAA made the components of the composite film interact with each other. BAA was well dispersed in the composite film, which significantly improved the mechanical properties of the composite film, and reduced its water content and UV transmittance. Furthermore, the color of BAA changed from red to yellow in the pH range of 1–14, which showed an obvious respond to pH. The composite film containing 15% BAA was sensitive to pH and thus could be used for monitoring shrimp freshness. On the 5th day of storage at 4 ℃, the total volatile basic nitrogen (TVB-N) content and pH of shrimp exceeded the spoilage threshold, indicating shrimp spoilage, and the color of the film changed from red to dark gray. Therefore, CS-SA composite films can be used as a good carrier for BAA to prepare an intelligent indicator film for shrimp freshness monitoring.

Carotenoids and fat-soluble vitamins (C&FSV) belong to the group of highly lipophilic food components that have important effects on the body’s health, which are ingested mainly through consumption of foods. The knowledge about the intestinal absorption mechanism of dietary C&FSV has been developed from partial C&FSV absorption through simple diffusion to specific transporter-mediated absorption of dietary C&FSV. This paper reviews the latest research progress in the process of digestion and absorption of C&FSV with special focus on, transporter-mediated apical transport, cytosolic transport and intracellular metabolism in enterocytes, and secretion from the basolateral membrane of enterocytes for the entire absorption process, and it provides a comprehensive summary of the regulation of C&FSV transporters. This review is expected to drive the understanding of the intestinal absorption mechanism of lipid-soluble bioactives so that they can better exert their beneficial health effects.

Oil bodies (OB) are subcellular organelles that store lipids in plant seeds, which are composed of neutral triacylglycerol (TAG), a monolayer of polar phospholipids surrounding TAG, and proteins embedded in the phospholipid membrane. The composition and unique structure of OB make it have good oxidation stability. OB can be extracted by water extraction and enzyme-assisted extraction. As a natural pre-emulsified oil-in-water emulsion, OB emulsions have been gradually used to replace synthetic oil droplets and are promising for broad applications in the fields of food, medicine and animal husbandry. Therefore, it is of practical significance to explore the effects of OB composition and structure as well as environmental factors on the oxidation stability of OB emulsions. In this paper, the composition, structure and extraction process of OB, the oxidation stability of OB emulsions and future prospects for its application in the food field are reviewed, which can provide a reference for the development and utilization of OB.

In China, a large amount of cereal bran is produced as by-product of cereal processing each year, which is rich in phenolic acids and non-digestible polysaccharides. However, the added value of cereal bran is low due to its low utilization rate. In recent years, feruloylated arabinoxylan oligosaccharides (F-AXOs) have been prepared from cereal bran. F-AXOs are functional oligosaccharides which have been identified as having dual physiological activities of ferulic acid and oligosaccharide, such as antioxidant and probiotic properties, making F-AXOs have broad application prospects. This review summarizes the methods used for the preparation and characterization of F-AXOs from cereal bran and the current knowledge about their structures. Finally, this review focuses on the relationship between the structures and biological activities of F-AXOs and describes the application of F-AXOs in the food industry. This review is expected to provide theoretical guidance for the preparation and application of F-AXOs.

Animal milk has become the major source of bioactive peptides due to its high contents of proteins and essential amino acids, high yield and good stability. Bioactive peptides are encrypted and inactive in the parental proteins, so they must be released to show their biological activity. Depending on their amino acid compositions, sizes, sequences, and physicochemical properties, bioactive peptides can exert angiotensin converting enzyme (ACE) inhibitory, antioxidant, antibacterial, antithrombotic, or immunomodulatory effects. Microbial fermentation is an effective method to prepare bioactive peptides. In this paper, the research progress in the preparation of milk derived bioactive peptides by microbial fermentation is reviewed, the diversity of bioactive peptides produced by different microbial proteases is clarified, and future trends for the preparation of bioactive peptides by microbial fermentation are discussed. This review is expected to provide a theoretical basis for the development and utilization of milk derived bioactive peptides in the future.

The level of cholesterol in the body is closely related to human health. Although cholesterol has many irreplaceable physiological functions, high cholesterol is one of the causes of many cardiovascular and cerebrovascular diseases. With more extensive and in-depth research on probiotics, many strains have been proved to have a good cholesterol-lowering effect, and their cholesterol-lowering effect has aroused more and more attention. Thus, the development and application of cholesterol-lowering probiotics have a bright future. In this paper, the mechanism of cholesterol synthesis and metabolism in the human body is briefly introduced in terms of its intake, synthesis, conversion and transport. The in vitro cholesterol-lowering mechanism of probiotics by absorbing and binding cholesterol as well as producing cholesterol-lowering metabolites, and the in vivo cholesterol-lowering mechanism of probiotics by inhibiting the intake and synthesis of cholesterol, promoting its transformation and regulating its transport are reviewed. Finally, the evaluation strategies for cholesterol-lowering probiotics are summarized including in vitro tests, animal experiments and clinical studies. This review is expected to provide a reference for the development of probiotic strains with a potent cholesterol-lowering effect.

The plant milk market has a promising future and flavor is a critical quality attribute of plant milk. The good flavors of plant milk such as milky, fruity, nutty, and cereal-like aromas are well-liked by consumers, while the undesirable flavors such as bitterness, bean-like odor, green odor, and mushroom-like odor severely limit the development of the plant milk industry. Based on the current state of development and future trends in raw material screening and processing technology for plant milk production and research on the flavor composition of plant milk, this paper summarizes the methods used for the extraction and identification of volatile substances from plant milk and the material basis of its flavor composition, highlighting the formation pathways of aroma and off-odor, the interaction between macromolecules and small molecules in plant milk, and the influential factors of and the regulatory strategies for the formation of aroma and off-odor in plant milk. This review is expected to provide scientific research ideas and strategies for maximizing the preservation of the good flavor of plant milk and avoiding the generation of undesirable flavors.

Sweet potato is a kind of low-calorie root food that has also been used for medicinal purpose. It is rich in a variety of essential nutrients and bioactive ingredients for the human body, and can be used to prevent various diseases. The quality of sweet potato directly affects its product quality, classification and quality grading and economic value. Rapid and efficient detection technologies play an important role in ensuring the quality and safety of sweet potato. Many studies on the rapid detection and analysis of sweet potato quality based on near-infrared spectroscopy (NIRS) have been reported. This paper comprehensively summarizes recent progress in the application of NIRS in the detection of the general chemical components (protein, starch, sugar, and water), active components (flavonoids and carotenoids), adulterants, heavy metals and microbial contamination in sweet potato as well as in its varietal identification. Moreover, this paper proposes future trends and research priorities for the application of NIRS in the quality detection of sweet potato. This review is expected to provide more references for further improvement of rapid quality assessment of sweet potato by NIRS and for the development of related fast testing equipment.

The cellar is the fermentation equipment and the main habitat of functional microorganisms for traditional Nongxiangxing Baijiu, and the quality of cellar mud largely determines the quality of Baijiu. Long-term practice and a large number of studies have shown that among the three major indicators that determine the quality of pit mud, the physicochemical factors are the basis, the microbial communities are the core, and the sensory indicators are the guide. The former two are interdependent and interact with each other, jointly acting on the last one. This paper presents a comparison of the research methods and findings on cellar mud quality in recent years in order to provide a quick overview of the cellar mud quality evaluation system and research evolution for the industry and to facilitate the production and subsequent research of Nongxiangxing Baijiu.

Omega-3 (ω-3) polyunsaturated fatty acids (PUFAs) are essential fatty acids for life activities, which cannot be synthesized by the body itself, and must be obtained from food. The role of ω-3 PUFAs in the prevention and treatment of chronic diseases has been widely demonstrated. In recent years, more and more studies have found that ω-3 PUFAs can promote recovery from exercise-induced muscle damage (EIMD), but the mechanism is not fully clarified. Therefore, in this paper, studies on the efficacy and mechanism of action of different doses of ω-3 PUFAs in promoting recovery from EIMD are reviewed. The underlying mechanism involves activating myogenic repair of myosatellite cells, enhancing plasma membrane repair of skeletal muscle cells, and increasing anti-inflammatory and antioxidant activity. This review should provide new ideas for further exploring the theory and practice of promoting recovery form EIMD from the perspective of sports nutrition.

Bioactive ingredients such as polyphenols and carotenoids have various health benefits such as anti-cancer and antioxidant activities. However, bioactive components are unstable and easily damaged in the gastrointestinal environment, making them unable to fully exert their functional effects. Proteins and polysaccharides can form complexes via non-covalent or covalent interactions, which have been widely used as encapsulation materials to enhance the stability and activity of bioactive compounds. This review summarizes the types of protein-polysaccharide complexes, and describes the application of the anti-solvent, pH-driven, thermal gelation and emulsification methods for the delivery of bioactive ingredients by protein-polysaccharide complexes. It is anticipated that this review will provide a reference for the research and application of bioactive compounds encapsulated in protein-polysaccharide complexes.

The viable but nonculturable (VBNC) state refers to a state in which bacteria lose their ability to grow and reproduce in conventional media under adverse environmental stress conditions. Bacteria in the VBNC state are usually still metabolically active and remain pathogenic and virulent. Bacteria in the VBNC state can recover and return to a state where they can be cultured normally under certain suitable conditions, posing potential risks to food safety. In this review, the morphological, physiological, biochemical and biomacromolecular characteristics of bacteria, especially foodborne pathogens, in the VBNC state are comprehensively described. Meanwhile, various factors that induce bacteria to enter the VBNC state, including temperature and pH unsuitable for bacteria survival, are summarized. The laboratory conditions for bacterial recovery from the VBNC state are outlined with special reference to adequate nutrition as an indispensable factor for recovery from the VBNC state. Finally, the major methods for the detection of bacteria in the VBNC state are discussed, including molecular biological methods, flow cytometry, and optical microscopy. Molecular biological methods have been widely used in the detection of bacteria in the VBNC state due to their advantages of accuracy, rapidity and high sensitivity. This review provides more ideas for further research on the induction, resuscitation and detection of foodborne pathogens in the VBNC state.

Chitosan, a natural linear cationic polysaccharide, can be used to design ‘green’ microparticles or nanoparticles to stabilize Pickering emulsions due to its good biodegradability and renewability. Therefore, it has found widespread food application prospect. Although chitosan has weak emulsifying ability, the active functional groups in its molecule can combine with other compounds through covalent or non-covalent interactions to form binary/ternary composite particles, which can improve its ability to stabilize emulsions. Environmentally responsive emulsions have recently become a popular research topic due to their ability to respond to different environmental stresses (pH and temperature). This paper summarizes recent progress in research on chitosan-based Pickering emulsions with respect to the types of chitosan-stabilized Pickering emulsions, graft-modified chitosan composite particle-stabilized Pickering emulsions and environmentally responsive emulsions, and it discusses the application of chitosan-based Pickering emulsions in food preservation, 3D food printing and functional factor carriers, as well as the obstacles encountered. Future prospects for the development of chitosan-based Pickering emulsions are proposed to provide a basis for the in-depth expansion of their applications in food.

Kidney beans are one of the most important economic legumes in China, and are cultivated extensively worldwide for their high nutritional value. However, food safety incidents caused by improper or inadequate cooking of kidney beans have occurred from time to time, which are generally believed to be associated with the toxicological effects of kidney bean lectins. Immunological studies show that lectins may be the major allergen in kidney beans, which have attracted significant research interest in foreign countries but have not been systematically reported in China. Therefore, in order to provide a theoretical basis for the development of hypoallergenic kidney bean foods and the rational development and utilization of kidney bean proteins, this article summarizes recent progress in immunological research on kidney bean lectins, analyzes the evidence that kidney bean lectins are allergens, and reviews food processing strategies for reducing the allergenicity of kidney bean lectins.

Contamination of spoilage and pathogenic microorganisms in food substrates can negatively influence food quality and threaten food safety. The application of physicochemical antimicrobial strategies can effectively inhibit the growth and reproduction of harmful microorganisms, but may also cause irreversible negative effects on food quality. Some antagonistic yeasts alone or combined with antimicrobial agents can effectively control harmful microorganisms. This review systematically and comprehensively summarizes the existing literature on the antimicrobial effects and mechanisms of yeasts and their derivatives from the above two aspects. The sources, species and mechanism of action of antagonistic yeasts as well as their antimicrobial effects when combined with other antimicrobial technologies are discussed. Additionally, the advantages and limitations of yeast as a natural drug carrier combined with various chemical antimicrobial agents are analyzed. This review aims to provide a scientific reference for developing new yeast-based antimicrobial agents, which will be helpful in improving food quality and ensuring food microbial safety.