In order to investigate the effect of differential expression of heat shock protein family A (Hsp70) member 6 (HSPA6) on the meat quality of Qinchuan cattle during postmortem maturation, the Longissimus dorsi muscle of Qinchuan cattle was stored at 4 ℃ and evaluated for meat quality at 0, 2, 4, 6 and 8 days postmortem. 4D-Label free quantification (4D-LFQ) was used to analyze the expression of HSPA6 and related differential proteins. The results showed that the expression of HSPA6 decreased with increasing storage time, the contents of adenosine triphosphate (ATP), adenosine diphosphate (ADP), adenosine monophosphate (AMP) and reduced form of nicotinamide-adenine dinucleotide (NADH) decreased, the myofibril fragmentation index (MFI) increased, and the shear force and centrifugal loss increased and then decreased. Correlation analysis showed that HSPA6 expression was positively correlated with the contents of ATP and NADH and shear force (P < 0.05) and negatively correlated with MFI and centrifugal loss (P < 0.01), indicating that HSPA6 degradation was closely related to energy metabolism and water retention in beef during storage. Proteomics identified 24 significantly differentially expressed proteins (DEPs) associated with HSPA6 expression, which could cause proteasome-mediated ubiquitin-dependent proteolytic metabolism and cellular proteolysis through carbohydrate derivative binding and purine nucleoside triphosphate binding, in turn causing metabolic disorders or imbalances. These DEPs could also control protein degradation and cell apoptosis, in turn affecting structural changes in muscle and reducing tissue energy levels, and ultimately affecting the tenderness, MFI and water retention of Qinchuan beef through resistance to cellular structural protein degradation.

In order to explore the effect of combined high-pressure and thermal treatment on the lipolysis of phospholipids in pork, the phospholipid degradation kinetics of pork was studied in the 300 to 700 MPa pressure range and in the 20 to 60 ℃ temperature range. It was found that the lipolysis process followed first-order kinetics. The lipolysis rate constant (k) of polyunsaturated fatty acids (PUFA) was the highest, followed by total phospholipids (PL), and those of monounsaturated (MUFA) and saturated fatty acids (SFA) were relatively low. The average activation energies of SFA and MUFA were the highest, and the absolute values of the average activation volume were at a high level. Hence, the lipolysis rate constants of SFA and MUFA were sensitive to temperature and pressure. Kinetic models for PL lipolysis were established using the Arrhenius and Eyring equations. Both models had good fitness to the data and showed similar temperature-pressure contour curves. Accordingly, the lipolysis kinetics of different phospholipid components was different, but the lipolysis kinetics of PL was very similar to that of PUFA. The kinetic models could predict the degree of lipolysis of phospholipids under preset pressure, temperature and time conditions, which will be helpful in designing or optimizing high-pressure processing parameters to improve the quality of meat products.

This study investigated how to reduce the content of N-hydroxyacetylneuraminic acid (Neu5Gc) in pork. By using Neu5Gc standard solution, porcine submandibular gland mucin (PSM) solution, meat pieces and minced meat as experimental subjects, and high performance liquid chromatography with fluorescence detection (HPLC-FLD) for quantitative analysis, the effect of pulsed electric field (PEF) treatment (with 50 cycles of electric shock at 1–4 kV/cm) on the content of total and free Neu5Gc and eating quality attributes (pH, color difference and texture quality) in pork was explored. The results showed that the content of free Neu5Gc in Neu5Gc standard solution showed a decreasing trend as PEF intensity increased, and significantly decreased at PEF intensity of 3 and 4 kV/cm (P < 0.05). The contents of total, free and bound Neu5Gc in PSM solution also decreased significantly (P < 0.05) with increasing intensity of PEF. The contents of total and bound Neu5Gc in meat pieces showed a decreasing trend while the content of free Neu5Gc increased, and the contents of total and bound Neu5Gc were significantly lower than those in the control group at 4 kV/cm (P < 0.05). The contents of total and bound Neu5Gc in minced meat showed a decreasing trend, and were significantly lower in all treatment groups than in the control group (P < 0.05). Compared with the control group, there was a significant difference (P < 0.05) in the pH of meat pieces treated at PEF intensity of 2 and 4 kV/cm. The brightness L* value of meat pieces and minced meat first increased and then decreased, reaching a maximum level at 3 kV/cm. The chewiness and elasticity of PEF-treated meat pieces were significantly lower than those of the control group (P < 0.05). The hardness and chewiness of minced meat tended to decrease, but there was no significant change in the elasticity (P > 0.05). Therefore, PEF can effectively reduce the content of Neu5Gc in pork and the chewiness and elasticity of pork pieces, but it also shows an adverse effect on the pH and color of pork.

The effects of ultrasound treatment at different powers (20 kHz for 6 min; 0, 150, 300, 450 and 600 W) on the structure, physicochemical properties and emulsifying properties of pale, soft and exudative-like (PSE-like) chicken meat myofibrillar protein (MP) were investigated. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed no significant changes in the composition of MP after ultrasound treatments; however, the band intensities of myosin heavy chain and actin were significantly increased at ultrasonic power of 450 and 600 W (P < 0.05). The α-helix content, surface hydrophobicity and solubility of MP increased and the β-fold content decreased as the ultrasonic power increased to 450 W. The α-helix content, surface hydrophobicity and solubility of MP decreased at 600 W ultrasonic power, but they were still significantly higher than those of the control group (P < 0.05). With an increase in ultrasound power, the fluorescence intensity of MP increased, and the particle size and zeta potential of MP and MP emulsion decreased significantly (P < 0.05). At ultrasonic power of 600 W, the highest emulsification activity index (EAI) and emulsion stability index (ESI) of MP, and the lowest oil/water interfacial tension and Turbiscan stability index of MP emulsion were obtained, indicating the highest emulsion stability. The cold field emission scanning electron micrograph confirmed that the oil droplets of the emulsion were smaller and more uniform. In summary, ultrasonic treatment can change the structure and physicochemical properties of PSE-like chicken MP, in turn improving the emulsion stability.

The main purpose of this study was to improve the function and quality of frozen purple sweet potato cubes. In this study, osmotic dehydration (OD), natural drying, hot air drying and freeze drying (FD) were used as pretreatment methods to evaluate the changes in anthocyanin composition of purple sweet potato after freezing and thawing, and to identify the most effective pretreatment methods to reduce the loss of anthocyanin in the freeze-thawing process. The results showed that after freezing and thawing, OD-treated purple sweet potato exhibited a significant decrease in total colordifference compared with the other pretreatment groups (P < 0.05), and the colour was closest to that of the fresh samples. Compared with other treatment groups, OD and FD pretreatment could significantly inhibit the polyphenol oxidase (PPO) and peroxidase (POD) activities of purple sweet potato after dehydration (P < 0.05), while the OD-treated group had the lowest PPO and POD activities. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging capacity and total antioxidant capacity were maintained at a higher level in the OD- and FD-treated groups compared to the other pretreatment groups. Twenty-seven Anthocyanins in purple sweet potato were lost after freezing and thawing. Compared with other pretreatments, OD pretreatment minimised the loss of anthocyanins after dehydration and freeze-thawing of purple potato cubes. Therefore, OD is the most effective pretreatment method for anthocyanin protection infrozen purple sweet potato, which is suitable for freezing storage of purple sweet potato to be used for anthocyanin extraction.

In order to study the effect of polysaccharides produced by Antrodia cinnamomea in submerged fermentation on the intestinal flora of mice and, more broadly, to develop the potential and application value of A. cinnamomea in the field of functional food, we extracted and characterized intracellular polysaccharides (AIPS) and exopolysaccharides (AEPS) from the submerged cultured mycelia and broth of Antrodia cinnamomea. It was found that AIPS and AEPS were predominantly composed of glucose, galactose and mannose. Their average molecular masses were 3.52 × 106 and 4.16 × 105 Da, respectively. AEPS contained a pyran ring, while AIPS had (–C≡C–H) and (C–O) functional groups. Both AIPS and AEPS had strong digestive resistance as demonstrated by their resistance to α-amylase digestion and simulated gastric digestion. Intragastrically administered AIPS and AEPS significantly increased the relative abundance of some beneficial microorganisms (such as Lactobacillus) in the intestine of mice with lincomycin-caused diarrhea, and significantly reduced the relative abundance of some harmful microorganisms (such as Enterococcus, Staphylococcus, Parasutterella and Shigella) (P < 0.05), AEPS being more significantly better than AIPS. This study can provide a new idea and basis for the development of new multifunctional prebiotics.

Objective: To study the structure of BRAP-1, an acidic polysaccharide from Brassica rapa L. and its effect and mechanism on lipopolysaccharide (LPS)-induced lung injury in mice. Methods: The chemical composition, molecular mass, structure and monosaccharide composition were analyzed by the phenol-sulfuric acid method, the m-hydroxydiphenyl method, the Coomassie brilliant blue method, high performance gel permeation chromatography (HPGPC), Fourier transform infrared (FT-IR) spectroscopy and gas chromatography-mass chromatography (GC-MS). The mice in the control and model groups were gavaged with 0.5 mL/d of phosphate buffered saline (PBS) and those in the BRAP-1 groups 50, 100 and 200 mg/(kg mb·d) of BRAP-1 for 10 days, respectively. A lung injury model was established by intratracheal LPS infusion. Lung wet/dry mass ratio, broncho-alveolar lavage fluid (BALF) protein concentration and total cell count were measured and hematoxylin-eosin (HE) staining was performed to evaluate histopathological changes. An enzyme-linked immunosorbent assay (ELISA) was used to determine the contents of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-10 and interferon-γ (IFN-γ) in the serum of mice in each group. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to determine the mRNA expression of tumor necrosis factor receptor (TNFR), Toll-like receptor 4 (TLR4), nuclear factor kappa B p65 (NF-κB p65), IL-1β and NOD-like receptor 3 (NLRP3) in lung tissue. Results: Compared with the model group, BRAP-1 alleviated the pathological changes of lung tissue such as edema, alveolar infiltration, protein exudation and excessive cytokines release in mice with lung injury, and significantly decreased the mRNA expression of key genes in the NF-κB/NLRP3 signaling pathway. Conclusion: BRAP-1 has a significantly protective effect on LPS-induced lung injury in mice, and the mechanism may be associated with the regulation of the NF-κB/NLRP3 signaling pathway.

Crayfish (Procambarus clarkii) is nutritious and delicious, but its safety always worries consumers. This study aimed to investigate the microbial safety of frozen cooked crayfish. The total volatile basic nitrogen (TVB-N) content and pH of crayfish samples were measured to determine the end point of the shelf life. The structure and diversity of the microbial communities in the viscera and gills, muscle and shell of crayfish and the marinade were analyzed by high-throughput sequencing. The results showed that during the frozen storage of cooked crayfish, the pH of the viscera, gills and muscle decreased slowly, while the pH of the marinade and the shell increased first and then decreased. The TVB-N contents of all four samples showed an upward trend. On the 180th day, the TVB-N values of the muscle as well as the viscera and gills were 32.42 and 31.26 mg/100 g, respectively, which were higher than the accepted upper limit. The results of high-throughput sequencing showed that there were differences in the bacterial community structure of the four crayfish samples at the end of the shelf life. The decreasing order of the abundance of bacteria in these samples were marinade > viscera and gills > shell > muscle. The dominant bacterial genera in these samples were also different; Lactobacillus was dominant in the marinade. Psychrobacter and Vibrio were dominant in the viscera and gills, the dominant bacteria in the shell were Vibrio, Lactobacillus and Psychrobacter, and the dominant bacteria in the muscle were Psychrobacter and Acinetobacter. In conclusion, the microbial safety risk of the marinade and the viscera and gills in frozen cooked crayfish products was relatively high and could be reduced by combined use of various cleaning methods, adjusting the acidity of the marinade and using antibacterial agents.

This research was performed in order to investigate the alleviative effect of aged Wuyi rock tea on dextran sulfate sodium (DSS)-induced colitis in mice. Fifty C57BL/6JGpt female mice were randomly and equally divided into five groups: control, DSS, DSS + infusion of 20-year-old Wuyi rock tea (DSS + OT01), DSS + infusion of 10-year-old Wuyi rock tea (DSS + OT11) and DSS + infusion of fresh Wuyi rock tea (DSS + OT20). The physiological and histopathological conditions of mice after Wuyi rock tea interventions, and the changes of serum inflammatory factors and cecal microbiota were analyzed. The results showed that aged Wuyi rock tea could significantly alleviate the symptoms of body mass loss, diarrhea, bloody stool, and colon length shortening, reduce inflammatory cell infiltration, and significantly inhibit the secretion of pro-inflammatory cytokines. In addition, aged Wuyi rock tea could alleviate the disorder of the gut microbiota, significantly down-regulate the relative abundance of Proteobacteria, Enterobacteriaceae and Escherichia, and up-regulate the relative abundance of Verrucomicrobia and Akkermansia. In summary, aged Wuyi rock tea can alleviate DSS-induced colitis in mice, and the tea produced in 2011 is more effective than that produced in 2001, which may be due to proper oxidation of catechins such as epigallocatechin gallate to produce thearubigins, with better anti-inflammatory and antioxidant properties. In addition, aged Wuyi rock tea is able to maintain intestinal homeostasis by regulating the relative abundance of Escherichia and Akkermansia in the intestine, which in turn alleviates the symptoms of DSS-induced colitis in mice such as body mass loss, diarrhea, bloody stool, colon length shortening, mucosal and crypt damage, inflammatory cell infiltration, and serum inflammatory factor overexpression.

Objective: To investigate the ameliorative effect of Lactobacillus plantarum L15 on excessive exercise-induced skeletal muscle injury in rats. Methods: Forty-eight SD male rats were randomly divided into four groups: quiet control, exercise control, quiet + L15 administration and exercise + L15 administration. Six-week treadmill exercise was used to establish a model of excessive exercise. The daily dose of L. plantarum L15 (3 × 108 CFU) was 0.2 mL. The control groups were given the same volume of normal saline. Following six-week administration, body mass gain, intestinal permeability, and lipopolysaccharide content, antioxidant indexes, cytokine levels and nuclear factor-erythroid 2-related factor 2 (Nrf2) signaling pathway and nuclear factor kappa B (NF-κB) signaling pathway-related gene expression levels in skeletal muscle were measured, and histopathological changes of vastus lateralis muscle were observed. Results: L. plantarum L15 significantly increased body mass gain (P < 0.05), improved the histopathological changes of vastus lateralis muscle, and decreased D-lactic acid and diamine oxidase levels in the serum as well as lipopolysaccharide (LPS) content in the skeletal muscle of rats with excessive exercise. L. plantarum L15 significantly increased the levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and total antioxidant capacity (TAC) (P < 0.05 or P < 0.01), significantly decreased the content of malondialdehyde (MDA) (P < 0.05), and significantly up-regulated the mRNA expression levels of the Nrf2, HO-1 and NQO1 mRNA (P < 0.05 or P < 0.01). L. plantarum L15 significantly reduced the levels of pro-inflammatory cytokines (IL-6, IL-1β and TNF-α) and significantly increased the levels of anti-inflammatory cytokines (IL-10) (P < 0.05 or P < 0.01), as well as significantly down-regulated the mRNA expression levels of the TLR4, MyD88 and NF-κB genes (P < 0.01). Conclusion: L. plantarum L15 can improve intestinal permeability, reduce LPS levels in the skeletal muscle of rats with excessive exercise, and inhibit oxidative stress by regulating the Nrf2 signaling pathway. In addition, it also can reduce inflammation levels by regulating the NF-κB signaling pathway, thereby alleviating skeletal muscle injury caused by excessive exercise.

Ulcerative colitis is a chronic inflammatory bowel disease with unclear pathogenesis and is difficult to cure. The incidence rate is increasing year by year, and there is high drug dependence for the treatment of ulcerative colitis, which leads to obvious the treatment resistance to s side effects. Therefore, seeking natural health products for nutritional therapy has become an attention focus of attention. In this articlestudy, dextran sulfate sodium salt (DSS) was used to establish a mouse model of ulcerative colitis. The mice were intervened with 5-aminosalicylic acid (5-ASA) (130 mg/(kg mb∙d)) or pomegranate juice (30% and 100%, 10 mL/d). Body mass, disease activity index (DAI) and colon length were measured, liver and kidney function and oxidative stress were measured by biochemical kits, the levels of inflammatory factors were measured by enzyme-linked immunosorbent assay (ELISA), colon tissue sections were observed, and the contents of fecal short-chain fatty acids (SCFAs) were determined by gas chromatography-mass spectrometry (GC-MS). Finally, a comprehensive evaluation of the effect and mechanism of pomegranate juice against ulcerative colitis in mice was exploredperformed. Compared with the DSS group, body mass and colon length in the pomegranate juice intervention group was increased, DAI was decreased, liver and kidney functions were improved, and could the expression of proinflammatory factors was significantly decreased (P < 0.01). In addition, anti-inflammatory factor expression was significantly enhanced (P < 0.01), reduce the level of oxidative stress and the activity of inflammatory marker myeloperoxidase (MPO) were significantly reduced (P < 0.01), the level of up-regulate fecal SCFAs was up-regulated, andimprove the colonic epithelial structure was improved. Pomegranate juice can attenuate intestinal mucosal damage and liver and kidney dysfunction, and has a good therapeutic effect on DSS-induced ulcerative colitis in mice.

The alleviating effect and mechanism of cold shock pretreatment (−2 ℃ cold air for 3 h) on flesh browning in fresh-cut pitaya fruit was explored by evaluating its effect on the phenylpropanoid pathway and antioxidant system during storage. Results revealed that cold shock pretreatment efficiently inhibited the increase in electrical conductivity and malondialdehyde (MDA) content compared with the control. Cold shock pretreatment promoted the gene expression and activities of key enzymes (phenylalanine ammonia lyase, cinnamic acid 4-hydroxylase, and 4-coumarate-CoA ligase) related to phenylpropane biosynthesis, and improved the accumulation of total phenolics and flavonoids, as well as most individual phenolic compounds, which led to enhanced antioxidant capacity. The activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) were increased by cold shock pretreatment. In addition, cold shock pretreatment accelerated the production of superoxide anion and H2O2 at the early stage of storage, but had no effect on their peaks and led to lower levels of superoxide anion and H2O2 afterwards, alleviating flesh browning in fresh-cut pitaya fruit. These results indicated that cold shock pretreatment can effectively alleviate wound-induced oxidative stress by modulating the phenylpropanoid pathway and reactive oxygen species (ROS) metabolism, thus inhibiting flesh browning in fresh-cut pitaya fruit.

Peanut is an important oilseed crop, susceptible to quality deterioration under harsh storage conditions because of its high oil content. In order to explore the effects of different storage temperatures on peanut quality under normal humidity conditions, in-shell peanuts were stored at 15, 25 or 35 ℃ for up to 30 weeks. Indicators of lipid oxidation: acid value (AV), peroxide value (PV), and malondialdehyde (MDA) content; indicators of protein oxidation: carbonyl, sulfhydryl, disulfide bond contents; and the activities of oxidation-related enzymes: lipase (LPS), lipoxygenase (LOX) and peroxidase (POD) were tested. The results showed that the AV increased from (0.48 ± 0.01) to (1.78 ± 0.02) mg/g and the carbonyl content from (3.19 ± 0.24) to (118.61 ± 6.41) μmol/g over the storage period at 25 ℃. Meanwhile, at the end of storage, the highest lipase and lipoxygenase activities were observed in the sample stored at 35 ℃, which were (59.00 ± 1.70) and (1 287.17 ± 98.45) U/g, respectively; the AV increased from (0.48 ± 0.01) to (3.15 ± 0.10) mg/g, the MDA content from 23.03 to 1 039.63 nmol/g, and the carbonyl content from (3.19 ± 0.24) to (124.86 ± 3.07) μmol/g. At 15 ℃, the highest lipase and lipoxygenase activities were only (41.60 ± 1.23) and (1 036.14 ± 34.49) U/g, respectively and the peroxide and carbonyl contents increased by 18.4 and 17.1 times after 30 days of storage, respectively, reaching much lower levels than those at the other temperatures. In conclusion, storage at normal humidity and at 15 ℃ can effectively suppress the oxidase activity at a low level at all time points, resulting in a low degree of oxidation of peanut oil and protein, while high ambient temperature increases the oxidase activity, and the higher the temperature, the higher the enzyme activity, and the higher the contents of primary and secondary oxidation products in oil, indicating a higher degree of peroxidation. Moreover, protein oxidation also occurs due to the oxidation of amino acid side chains and protein structural damage, ultimately leading to a decline in peanut quality.

The aim of this study was to evaluate the combined effect of gaseous ozone (OG) and perforated modified atmosphere packaging (MAP) on the preservation of Chinese bayberry. In order to determine the optimal storage conditions, different modified atmospheres and different concentrations of OG were used separately or in combination to treat Chinese bayberry. Results showed that the optimum modified atmosphere for packaging of Chinese bayberry was 10% O2 + 10% CO2 + 80% N2, which could maintain dynamic equilibrium when a microporous film with two perforations of 100 μm in diameter per 243.39 cm2 was used, and the optimal OG concentration was 18.3 mg/m3. The single treatments with OG or perforated MAP inhibited the decay incidence and maintained high contents of total phenols, anthocyanins and flavonoids in Chinese bayberry. The combined treatment was more effective in preserving the quality of Chinese bayberry, slowing down the decline of fruit firmness, and reducing the losses of total soluble solids (TSS), titratable acid (TA) and ascorbic acid (ASA). In addition, the activities of peroxidase (POD) and superoxide dismutase (SOD) in the combined treatment group were 1.42 and 1.9 times higher than those in the untreated control, respectively, indicating reduced accumulation of H2O2 and O2-·, so that the mold free shelf life was extended up to 8 d.

The use of plant essential oils as an antibacterial agent for food packaging has become a new trend. In order to obtain biodegradable films for the preservation of aquatic products, coaxial electrospinning films were prepared by electrospinning using the antimicrobial preservative oregano essential oil (OEO) or its main components as core material, pullulan (Pul) as film-forming substrate, and thermoplastic polyurethane (TPU) as shell material and were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy. Also, its thermal stability, physicochemical properties was determined as well as the release performance of the antimicrobial preservative from the coaxial electrospinning films and its efficacy in preserving the quality of refrigerated Lateolabrax japonicus fillets. The results showed that OEO was effectively encapsulated in the electrospinning fibers, improving the micromorphology, water vapor barrier properties and wettability and significantly reducing the tensile strength (TS), and swelling degree (SD) of the film (P < 0.05), but not changing the thermal stability of the film significantly. The fibers inside the film had a coaxial core-shell structure, and the release behavior of the preservative was a complex coupling of disintegration and dissolution, resulting in controlled OEO release for up to 60 h. In addition, the film effectively inhibited the growth of microorganisms, and thus had excellent preservative effect on fresh L. japonicus fillets. It effectively delayed the deterioration of the smell, texture and apparent quality of the fillets, and extended the shelf life from 8 to 12 d. This study can provide a theoretical basis and technical support for the development of biodegradable antibacterial packaging materials based on biological antibacterial agents.

In order to explore the effect of postharvest treatment with combined phenylalanine (Phe) and 1-methylcyclopropene (1-MCP) on the appearance quality of peach fruits, bagged peach fruits were treated after harvest with water (control), Phe, 1-MCP or Phe combined with 1-MCP (Phe + 1-MCP). The changes in peach fruit phenotype, peel color difference, anthocyanin content, and the expression of genes associated with anthocyanidin and ethylene metabolism were measured during storage. The results showed that the single treatments with Phe or 1-MCP led to a higher peel anthocyanin content compared with the control group. Furthermore, the combined treatment was more effective in increasing the synthesis of anthocyanin than the single treatments. On the 6th day of storage, the anthocyanin content in the peel in the combined treatment group was 76.71 mg/kg, which was 7.29, 3.36, and 1.33 times higher than that in the control, Phe and 1-MCP groups, respectively. Phe + 1-MCP treatment effectively enhanced the expression of genes related to the synthesis of anthocyanins (PAL, CHS, CHI, F3H, DFR, ANS, UFGT, MYB10.1, bHLH-3 and WD40-1) and reduced the expression of genes related to ethylene synthesis and signal transduction (ACS, EIN4 and EIL) in peach peel. This study not only further confirmed that 1-MCP treatment can effectively promote the synthesis of anthocyanin in peach peel, but also found a synergistic effect between Phe and 1-MCP, which will provide a theoretical basis for the application of Phe + 1-MCP in the regulation of peach color after harvest.

To explore the effect of slightly acidic electrolyzed water (SAEW) on chlorophyll degradation in postharvest broccoli, the pattern of changes in the color, total chlorophyll content, chlorophyll derivative content, chlorophyll degrading enzyme activities, and key chlorophyll metabolism-related gene expression of postharvest broccoli after treatment with 50 mg/L SAEW was analyzed. The results showed that SAEW treatment could effectively slow down the degradation of total chlorophyll, maintain the contents of chlorophyll derivatives chlorophyll a, chlorophyll b, chlorophyllide a, chlorophyllide b, pheophorbide a, and pheophytin a, and delay the increase in the activities of chlorophyll metabolizing enzymes, Mg-dechelatase, pheophytinase, and pheophorbide an oxygenase in postharvest broccoli. Meanwhile, it significantly inhibited the expression of the genes encoding chlorophyll b reductase, chlorophyllase 1, chlorophyllase 2, chlorosis protein, pheophytinase, pheophorbide an oxygenase, red chlorophyll catabolite reductase, and aging specific cysteine protease, thereby allowing color protection and freshness preservation. In conclusion, SAEW can be used as an effective method to delay postharvest chlorophyll degradation and inhibit yellowing and senescence in broccoli.

The sensitivity of freshness indicator labels/films has become an important research direction of intelligent food packaging. In this study, a high-sensitivity indicator film containing gelatin and Fe2＋ was prepared by electrospinning using blueberry anthocyanins as the indicator and zein as the matrix for monitoring fish freshness. The validity and sensitivity of the indicator film for detecting the freshness of silver carp were tested and the potential mechanism was elucidated. The results of pH sensitivity, ammonia sensitivity and anthocyanin release showed that the addition of gelatin and Fe2+ improved the sensitivity of the indicator film to pH and ammonia, and contributed to better binding of the anthocyanins in the film. There was a strong correlation between the color response (P = (L* + a* + b* + R + G + B)/a*) of the film and the content of total volatile basic nitrogen (TVB-N) content in fish meat as a freshness indicator (R2 > 0.98). In conclusion, the prepared indicator film can effectively monitor fish freshness, and the hydrogen bond interactions between anthocyanins and gelatin/Fe2+ may affect the color response characteristics and sensitivity of the indicator film.

In order to investigate the effect of ultraviolet-C (UV-C) irradiation combined with chitosan (CH) coating on the storage quality of Hami melon, changes in the physiological quality and antioxidant enzyme activities of ‘Xizhoumi 17’ Hami melon from Xinjiang were determined during storage at (5 ± 1) ℃ after the combined treatment. The results indicated that both single and combined treatments effectively delayed the changes in the storage quality of Hami melon, with the combined treatment being most effective. On the 49th day of storage, the fruit firmness of the combined group was 1.13 times higher, and the contents of soluble solids and titratable acids were 1.14 and 1.35 times higher than those of the control group, respectively; the contents of ascorbic acid and total phenols increased by 23.40% and 32.51%, respectively, and the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POD) by 12.70%, 73.53%, 26.43% and 28.14%, respectively. In conclusion, UV-C combined with CH coating can effectively maintain the postharvest storage quality of Hami melon. This study can provide a reference for the postharvest preservation of Hami melon.

To solve the problem of rapid deterioration and short shelf life of fresh-cut potatoes, this experiment investigated the effect of heat treatment at 45 ℃ for 3 min combined with vacuum packaging or 30% CO2 + 70% N2 modified atmosphere packaging on the storage quality of fresh-cut potatoes. The results showed that the combination of heat treatment and modified atmosphere packaging suppressed the increase in the respiration rate of fresh-cut potatoes, significantly inhibited the increase in malondialdehyde content (MDA) as well as phenylalanine ammonia-lyase (PAL), peroxidase (POD), polyphenol oxidase (PPO) activities (P < 0.05), effectively maintained the contents of total phenol, ascorbic acid (AsA), soluble solids and starch, restrained the increase in total bacterial count, and preserved the volatile flavor and sensory quality of fresh-cut potatoes. In conclusion, heat treatment combined with modified atmosphere packaging can preserve the sensory and nutritional quality of fresh-cut potatoes, and inhibit the growth of microbes and browning enzyme activities, thereby extending the shelf life of fresh-cut potatoes.

In order to study the effect of nitric oxide (NO) on the storage quality of hyacinth bean after harvest, sodium nitroprusside (SNP) was used as an exogenous NO donor in this study. Hyacinth bean was soaked in 0.2 mmol/L SNP solution or distilled water as control for 10 min and then stored at (20 ± 1) ℃ and 80%–90% relative humidity. Decay incidence, rust incidence, hardness, the contents of total soluble solids (TSS), malondialdehyde (MDA), flavonoids, total phenols and chlorophyll, and the activities of antioxidant enzymes (peroxidase (POD), polyphenol oxidase (PPO), phenylalanine ammoniase (PAL), catalase (CAT) and ascorbate peroxidase (APX)) were observed during the storage period. The results showed that exogenous NO treatment could inhibit the rot and rust, keep the color and hardness, and inhibit the degradation of TSS and chlorophyll in hyacinth bean, so that hyacinth bean could maintain good sensory quality. Exogenous NO treatment could also prevent the accumulation of MDA and increase the contents of total phenols and flavonoids. In addition, exogenous NO treatment maintained the activities of PAL, CAT and APX during storage, and inhibited the increase in the activities of POD and PPO, thereby enhancing the antioxidant capacity and delaying the maturation and senescence of hyacinth bean. In conclusion, exogenous NO treatment can delay the postharvest maturation and senescence, maintain the physiological quality during storage, and effectively prolong the shelf life of hyacinth bean.

Acetic acid is the major volatile acid in fruit wine and an excessive content of acetic acid will seriously affect the sensory quality of fruit wine. During alcoholic fermentation, acetic acid is mainly formed by the metabolism of Saccharomyces cerevisiae. Therefore, fully understanding the regulation mechanism of acetic acid metabolism by S. cerevisiae, and breeding low acetic acid-producing strains are of great significance to solve the problem of excessive acetic acid in fruit wine. In this paper, recent progress in research on the metabolic pathways and key regulatory genes of acetic acid in S. cerevisiae is reviewed. Furthermore, this paper proposes the idea that omics technologies and quantitative trait locus mapping could be applied to explore the molecular mechanism of the regulation of acetic acid production by S. cerevisiae. Finally, the application of three functional strain-breeding methods in the breeding of low acetic acid-producing strains is summarized. This review is expected to provide a reference for obtaining excellent strains with low yield of acetic acid for precise regulation of acetic acid in fruit wine.

As a phenotypically and phylogenetically diverse group, lactic acid bacteria are found in a variety of natural environments and play an important role in medicine, bioengineering, food fermentation and agriculture. Lactic acid bacteria have a long history of use in food and have been considered as suitable vehicles for the production and targeted delivery of health-promoting or therapeutic bioactive substances due to their safety and probiotic properties, and the operability of their genetic systems. This article summarizes the latest studies on lactic acid bacteria as delivery vehicles in vivo with a focus on gene expression systems of lactic acid bacteria, the expression forms of bioactive substances and the application of lactic acid bacteria as delivery vehicles in the treatment of various diseases. It is hoped that this review will provide a basis for subsequent research.

Bacteria mainly exist in the form of a biofilm in nature. The initial adhesion of bacteria starts the life cycle of biofilm formation. Initial adhesion is a process in which bacteria in a planktonic state adsorb on biotic/abiotic surfaces and begin to form biofilms under the influence of factors such as bacterial components and extracellular polymeric substances. The initial adhesion of bacteria is affected by various regulatory systems. Therefore, it is of significance to study these regulatory systems. This article reviews three major regulatory systems that affect initial bacterial adhesion, namely, cyclic diguanylate (c-di-GMP) system, two-component system and quorum sensing system, and introduces the mechanisms of how these regulatory systems regulate initial bacterial adhesion. Also, the application of controlling initial bacterial adhesion to ensure food quality is summarized and future prospects are discussed. This reviews is expected to provide a theoretical basis for protecting food quality from being harmed by bacterial biofilm, which is of practical significance for promoting the development of the food industry.

The major route of rapeseed utilization is by the preparation of rapeseed oil. Different oil preparation technologies have a significant influence on lipid concomitants (including polyphenols, phytosterols, tocopherols, and β-carotene) in rapeseed oil. Lipid concomitants are an important part in rapeseed oil quality, so it is crucial to understand the changes of lipid concomitants during rapeseed oil production. The aim of this review is to summarize the major outcomes of recent research on the influence of different oil preparation technologies on lipid concomitants in rapeseed oil with a focus on pretreatment technologies (including pulsed electric field, microwave, and roasting/steaming), oil extraction technologies (including supercritical carbon dioxide extraction, aqueous enzymatic extraction, and solvent extraction) and refining processes (including degumming, deacidification, decolorization, and deodorization). We hope that this review will provide a theoretical basis for the development of green and efficient technology for rapeseed processing.

L-Methionine is the only sulfur-containing essential amino acid. It acts as a precursor in the synthesis of various biologically active substances and participates in various metabolic pathways in the body. It is widely used in food, animal feed, medicine, cosmetics, and other fields. In recent years, since L-methionine is the only essential amino acid that cannot be industrially produced by microbial fermentation, the potential of metabolic engineering to improve L-methionine production has received widespread attention from researchers around the world. In this paper, the biosynthesis pathways and metabolic regulation mechanisms of L-methionine in Corynebacterium glutamicum and Escherichia coli are analyzed and compared. The metabolic engineering strategies to produce L-methionine are reviewed from five aspects: the removal of feedback inhibition of key enzymes, the cut-off or weakening of branch metabolic pathways, the optimization of the central metabolic regulatory network, the enhancement of cofactor supply, and the optimization of transport systems, and recent progress in research on the biosynthesis of L-methionine is summarized. Finally, future prospects are also discussed. It is hoped that this review will provide a basis for the breeding of high-yield L-methionine-producing strains.

Plasmin is an important factor affecting the shelf-life quality of milk products, and its hydrolytic activity is regulated by many factors, such as activators, inhibitors, and activator inhibitors. Compared with protease secreted by psychrophilic bacteria, plasmin presents different thermal inactivation parameters and hydrolysis properties; the milk gelation properties induced by the two enzymes, the gelation mechanisms and the methods used to detect the milk hydrolysates are different. Plasmin activity in raw milk is affected by dairy cow breeds, lactation stage, parity, and the number of somatic cells, as well as protease secreted by bacteria. As whey protein, casein and Maillard reaction can affect plasmin structure and substrate recognition by it, heating, membrane filtration, and high pressure processing can affect plasmin activity. In this paper, we summarize the composition and regulatory mechanism of the plasmin system in milk, the mechanism of plasmin-induced age gelation of milk, the factors affecting plasmin activity and the methods used to assay plasmin activity, with the aim to provide a reference for further research on milk plasmin.

Aroma is one of the important indexes to measure the organoleptic quality of fruit wine. However, the weak aroma restricts the further improvement of fruit wine quality. The aroma enhancement of fruit wine is one of the focuses of attention for relevant practitioners. However, the complicated mechanism of aroma regulation is a bottleneck problem that restricts the creation of aroma-enhancing techniques for fruit wine fermentation. In this paper, we provide a systematic review of the mechanism of the influence of starter cultures, enzymes, and pretreatment before fermentation on the aroma of fruit wine with regard to the types of key aroma compounds and their formation pathways, and we discuss the application of modern biotechnology in the breeding of excellent aroma producing yeast. Finally, we discuss future directions in the research on fruit wine flavor.

Yoghurt has high nutritional value and health-promoting functions; however, its quality defects such as whey syneresis and poor coagulation affect the sensory experience of consumers. Researchers commonly use food macromolecules to improve the gel stability and sensory properties of yoghurt by modifying the formation of gel networks or inducing the gelation of milk protein. In this review, we summarize the texture defects of yogurt, the factors influencing them, and the strategies to improve the gel stability of yogurt as well as the underlying mechanism. Also, we discuss future trends. This review will provide important guidance for improving the quality and stability of yoghurt products.

Protein is an important nutrient required by the human body. The change of protein structure during processing will lead to changes in its functional properties, in turn affecting the quality of foods. There are many physical methods available to alter the structure of proteins to expand their application in the food industry. The new electrophysical processing technology has become a hot spot in the field of food processing due to its advantages of high efficiency, low energy consumption, and slight loss of nutrients. Therefore, this paper reviews the effects of electric field technology (ohmic heating and electrostatic field) and electromagnetic field technology (microwave, radio frequency and magnetic field) on the change of protein structure at multiscales (macroscopic, molecular and microscopic levels), in order provide a theoretical basis for the development and utilization of electromagnetic field processed protein products.

With the current over-exploitation of terrestrial resources, multi-dimensional in-depth utilization of aquatic resources has attracted widespread attention. Blue foods including marine animals and algae supply nutrients to 3.2 billion people around the world. Polysaccharides are an important class of nutritional components in “blue foods”, and have various biological activities such as antitumor, anti-inflammatory, and anti-allergic functions. The exertion of these physiological functions is closely related to their immunomodulatory activities. Therefore, this article reviews recent progress on the classification, composition and immunomodulatory activities of polysaccharides in blue foods with a focus on the regulatory effects of polysaccharides in marine mollusks and seaweeds on innate/adaptive immune responses, the antitumor effects of pro-inflammatory polysaccharides, and their role in immune adjuvants, and the role of anti-inflammatory polysaccharides in autoimmune diseases and inflammation in an effort to enrich the understanding of the different immune effects of marine polysaccharides and to provide theoretical support for the development of immunomodulatory functional foods based on polysaccharides from blue foods.

Foods, agricultural by-products and medicinal plants are often contaminated by pathogenic fungi and mycotoxins. Pathogenic fungi not only lead to food deterioration, but also harm people’s health. The commonly used methods for detoxification include physical, chemical and biological methods. A large number of studies have shown that natural plant essential oils inhibit the growth of pathogenic fungi and the accumulation of mycotoxins and have good biodegradability, making them a promising environmental-friendly alternative to traditional synthetic fungicides. In this review, the classification and harm of common pathogenic fungi and mycotoxins, as well as the antifungal components and mechanisms of plant essential oils are introduced, and recent progress on plant essential oils in the control of pathogenic fungi and mycotoxins is summarized. This review provides a theoretical basis for the development and application of plant essential oils.

Water-in-water emulsions, which have a very low interfacial tension and a thick interfacial layer, are formed by two thermodynamically incompatible hydrophilic macromolecules in a certain proportion. It has been reported that the system cannot be stabilized by surfactants, but can avoid macroscopic phase separation by gelation of one or two phases. Recently, it has been found that the stability of water-in-water emulsions can be improved by the irreversible adsorption of solid particles at the interface based on the stabilization mechanism of oil-in-water Pickering emulsions. In this review, we summarize recent advances in research on the stabilization of water-in-water emulsions, and focus on the stability of Pickering emulsions stabilized by solid particles and its influential factors, as well as its applications in the food field. It is expected that this review will provide new ideas for food structure design based on the stabilization of water-in-water emulsions.

Biogenic amines (BA) are the general term for a class of bioactive low-molecular mass organic compounds containing amino groups. Excessive intake of BA will cause adverse physiological reactions and even endanger life. This article presents a systematic review of the sources, biosynthetic mechanism, microbial traceability, detection technologies, and influential factors of BA in wine, as well as the strategies used to control BA during winemaking. This article will provide theoretical guidance for efficient analysis and control of BA in wine, which will in turn promote the healthy and green development of the Chinese wine industry.

Dry-aging is the aerobic aging process where meat carcasses or primal cuts are hanged and aged for a period of time (28 to 55 days, or even longer) under specific environmental conditions of temperature (0–4 ℃), relative humidity (61%–85%), and air flow (0.5–2.0 m/s). Dry-aging in a breathable bag, dry-aging combined with ultraviolet irradiation treatment, and stepwise dry/wet-aging have been successively developed. Due to dehydration during dry-aging, the surface of meat shrinks to produce a hard ‘crust’, resulting in significant mass loss and trim loss. However, compared with wet-aging, dry-aging can significantly enhance meat flavor characteristics, imparting a strong ‘dry-aged flavor’ and unique roasted beef-like, roasted nutty and buttery aromas to aged meat. Dry-aging can be used effectively to improve the eating quality and economic value of low-marbled beef. In this paper, the key parameters of dry-aging are reviewed, the potential mechanism by which dry-aging improves meat quality, especially flavor, is discussed. Future prospects for the application and development of dry-aging are discussed as well. This review will provide theoretical support for the development of the meat industry and for exploring the market for high-quality meat.

Anthocyanins are natural colorants that have attracted increasing attention due to their wide color range, non-toxicity and health benefits. Although anthocyanins have great application potential in the food and pharmaceutical industries, their application is limited due to the relative instability. Starch is considered as a good protective agent for anthocyanins, which can improve the stability of anthocyanins during storage. In recent years, many studies have combined the two compounds by different methods such as physical and chemical methods. This can not only enhance the stability of anthocyanins, but also improve the mechanical properties of starch, which will result in better application of starch and anthocyanins in drug delivery, biomedicine, agriculture, and food production. The basic structural characteristics of anthocyanins and starch, and the various methods for preparing anthocyanin-starch complexes are summarized herein. Also, the effects of anthocyanin-starch interactions on anthocyanin stability, bioavailability and antioxidant activity and on starch crystallinity, gelatinization properties, mechanical properties and digestibility are reviewed, and the current progress in the application of anthocyanin-starch complexes is outlined. It is hoped that this review will provide a reference for future research on the preparation and application of anthocyanin-starch complexes.

Green sweat peppers are rich in nutrients and diverse in shape and color. Apart from being eaten as a vegetable, it is widely used as seasoning and side dishes. Due to respiration and infection by harmful microorganisms, postharvest green peppers are prone to water loss, wilting and even rot. Appropriate preservation technology can maximize the preservation of nutrients and extend the storage period of green peppers. This paper introduces the techniques used for postharvest preservation of green sweet peppers: physical preservation methods such as refrigeration and packaging, biological preservatives such as microbial, plant and animal extracts, and chemical preservatives such as calcium agents and 1-methylcyclopropene (1-MCP), and compares the advantages and disadvantages of these preservation techniques. It elaborates the effect of chitosan or konjac glucomannan-based composite coatings on preserving the quality of green sweet peppers. Our intention is to provide a reference and guidance for the storage and preservation of postharvest green peppers.

In recent years, an increasing number of studies have demonstrated the role of phages in controlling harmful microorganisms in foods. Due to their host specificity, phages are considered as an ideal tool to guarantee food safety. However, there are a series of limitations to the application of phages, so there have been few cases of the application of phages in the food industry. In this context, this paper discusses the frontier and hot issues in the application of phages in food safety, with a focus on the acceptability of the application of phages in the food industry, the potential risk of drug resistance transmission, the problem of phage resistance of bacteria, and the influence of complex food matrices on the effect of phages. Moreover, scientific and reasonable suggestions on the application of phages in the food industry are put forward. We hope that this review will promote the shift from basic research on phages to their application in the food industry.

There are various species of plants in the Lauraceae family, and these plants are widely distributed in China. Their essential oils have many biological activities, such as bacteriostatic, antioxidant and insect repellent activities and are ideal natural preservatives, effective antioxidants, and green insect repellents. Therefore, they are of research significance and have broad application prospects. The effects of the growth cycle, plant parts, extraction methods, and geographical environment on the major components of essential oils from Lauraceae plants (LEO) are reviewed with a focus on the antimicrobial, antioxidant and insect repellent activities and mechanisms of LEO. In addition, common edible coatings, microencapsulation, and nano-emulsion technologies based on LEO for food packaging and preservation are summarized. We hope that this review will provide a theoretical basis for the application of LEO in food preservation.

Glycinin and β-conglycinin are the major protein components of soybean, which are different in their structure. The preparation process can cause varying degrees of changes in the structures of glycinin and β-conglycinin. In this paper, a brief overview of the structures of various soybean protein components is given, with a focus on the preparation process of soybean proteins. Moreover, the mechanism for the effect of the structure of soybean protein components on their functions is summarized. This review is expected to provide a reference for the quality control of soybean and soybean protein products.

Color is an important factor affecting the sensory quality of fruit and vegetable (FV) products. The vibrant and stable color of FV products can give people a good visual enjoyment, which can in turn promote consumers’ appetite and increase the market value of the products. This paper summarizes the types and properties of natural colorants in FV, clarifies the effects of thermal and non-thermal drying technologies and their combination on the color of FV products, reveals the influence mechanism of colorant degradation products on the products’ quality, and reviews the color preservation technologies of dried FV. We hope that this review could provide a theoretical basis for the color preservation and quality enhancement of dried FV products.

With the popularity of various electronic devices and lighting products, the incidence of light-induced retinal damage has surged, which has become a major cause of visual health problems in modern society. A growing number of studies have found that dietary supplementation with nutrients such as anthocyanins, carotenoids, long-chain unsaturated fatty acids and vitamin A is effective in improving vision and enhancing the retina’s resistance to oxidative stress. Therefore, this paper reviews the mechanism of retinal photodamage and discusses the role of different dietary nutrients in improving light-induced retinal injury and the underlying regulatory mechanism. This review can provide a scientific basis for preventing and ameliorating retinal photodamage through dietary supplementation.

As an important nutrient in milk, fat exists in the form of milk fat globules. Cow’s milk is an important substitute for breast milk, but the difference between its milk fat globules and those of human milk remains to be clarified. In this paper, the main differences in protein composition, lipid composition, structure and function between cow’s and human milk fat globules are reviewed. The types of milk fat globule membrane proteins (MFGMPs) in human milk are significantly more than those in cow’s milk, and there are also obvious differences in the abundance of some special proteins. The composition and distribution of unsaturated and saturated fatty acids in cow’s milk and human milk are also different. Sphingomyelin is more abundant in human milk phospholipids, but in cow’s milk, lecithin is the main phospholipid. In all mammalian milk, the core of the lipid structure is triglyceride, encapsulated by a complex three-layer membrane. In terms of composition and structure, there is heterogeneity in milk fat globule membrane (MFGM) between the same species and different species. By summarizing the differences between human milk and cow’s milk fat globules, this review aims to increase the utilization rate and value of milk MFGM, to improve the structure of simulated milk fat globules, and to further optimize infant formula.

Bovine colostrum is the milk secreted by cows in the first few days after natural birth. It is rich in lactoferrin, immunoglobulin, antimicrobial peptides, growth factors and other active ingredients. The special nutritional composition of bovine colostrum endows it with a variety of biological activities, such as regulating immunity, improving gastrointestinal health, improving bone health and promoting wound healing. Therefore, bovine colostrum has attracted extensive attention as a functional food or functional milk ingredient. In this paper, the nutritional composition, biological functions and processing stability of bovine colostrum are described in detail, aiming to provide a reference for the development, application and standardized production of bovine colostrum.

Short chain fatty acid (SCFA), a class of fatty acids with six or less carbon atoms, have important physiological functions for human health. As metabolites of the intestinal flora, SCFA can maintain intestinal health. Furthermore, accumulating research has proved that SCFA have many functions such as maintaining brain and bone functions, participating in regulating the immune response, antibacterial and antitumor activity, and alleviating obesity and diabetes. In this paper, recent literature on the production, absorption and functions of SCFA in the body are reviewed to provide a theoretical reference for the research and application of SCFA in nutrition.