This study aimed to investigate the effect of ammonia mediated hypoxia inducible factor-1α (HIF-1α) expression on mitochondrial cell apoptosis and tenderness in yak meat after slaughter. Ten mmol/L ammonium chloride (NH4Cl), 0.9% normal saline (control) and 10 mmol/L N-nitro-L-arginine methyl ester hydrochloride were used separately for treating yak Longissimus dorsi. By measuring the expression of HIF-1α, nitrogen monoxide (NO) content, energy metabolism-related enzyme activities, adenosine triphosphate (ATP) level, mitochondrial pathway of apoptosis and muscle tenderness, we explored the mechanism of cell apoptosis and tenderness change in yak meat after slaughter. The results showed that during the postmortem aging of yak meat, the expression of HIF-1α and the content of NO in each treatment group increased first and then decreased, and so did the activities of Na+-K+-ATPase, Ca2+-ATPase, caspase-9 and caspase-3 and shear stress. ATP content, the degree of mitochondrial permeability transition pore (MPTP) opening, mitochondrial membrane potential (MMP), and muscle fiber diameter and area showed a gradual downward trend, and myofibril fragmentation index (MFI) and the gap between muscle cells showed an opposite trend. During 6 to 24 h after slaughter, the expression of HIF-1α and the content of NO in the NH4Cl treatment group were significantly higher than those in the control group (P < 0.05), which were significantly higher than those in the L-NAME treatment group (P < 0.05). The ATP content in the NH4Cl group was significantly higher than that in the control and L-NAME groups during 6 to 72 h after slaughter. The activities of Na+-K+-ATPase and Ca2+-ATPase in the control group were significantly higher than those in the NH4Cl group (P < 0.05), but significantly lower than those in the L-NAME group (P < 0.05). During 6–120 h after slaughter, the opening of MPTP in the control group was significantly higher than that in the NH4Cl group (P < 0.05), but lower than that in the L-NAME group (P < 0.05). During 0 to 168 h after slaughter, the opening of MMP decreased by 47.72% in the NH4Cl group, 53.54% in the control group, and 60.05% in the L-NAME group. During 6 to 72 h after slaughter, the activities of caspase-9 and caspase-3 in the NH4Cl group were significantly lower than those in the control group (P < 0.05), which were lower than those in the L-NAME group (P < 0.05). During 6 to 120 h after slaughter, shear force and muscle fiber area and diameter in the NH4Cl group were higher than those in the control group, and MFI and the gap between muscle fibers in the NH4Cl group were lower than those in the control group, while the opposite result was observed for the L-NAME group. In conclusion, ammonia decreased the activities of Na+-K+-ATPase and Ca2+-ATPase and increased the content of ATP by up-regulating the expression of HIF-1α, which in turn regulated the energy metabolism of muscle cells and maintained the stability of the internal environment. By inhibiting the opening of MPTP and the decrease in MMP, ammonia reduced the activity of caspase-3/9, and inhibited mitochondrial cell apoptosis, thereby resulting in an increase in shear stress, a decrease in MFI and morphological changes of muscle cells, and finally causing a negative effect on the tenderness of yak meat.

The chemical components of edible sweet-scented osmanthus flowers (Osmanthus fragrans (Thunb.) Lour.) vary at different heat treatment temperatures, so it is extremely necessary to explore the effect of different heating temperatures on the eating quality of sweet-scented osmanthus. In this work, changes in the bioactive ingredients, antioxidant property, color and flavor substances of unheated (control) and heated (at 80, 100 or 120 °C for 20 min) flowers of Osmanthus fragrans ‘Boyejingui’, ‘Echengdangui’ and ‘Wanyingui’ were determined. The results showed that with an increase in heating temperature, the content of bioactive ingredients decreased significantly (P < 0.05), and the loss rates of flavonoids, polyphenols and anthocyanins were up to 37.44%, 28.74% and 49.10%, respectively. The antioxidant capacity decreased initially and then increased, and the radical scavenging capacity of the sample heated at 120 ℃ increased by 6.52% compared with that of the sample heated at 100 ℃. The color difference significantly increased (P < 0.05), the bitterness increased, and the astringency decreased first and then increased. Compared with the control group, furans, nitrogen-containing heterocycles and phenols were exclusively found in the sample heated at 120 ℃ at a level of 6.21%. The number of species of characteristic aroma components progressively decreased but a caramel-like aroma was formed. Therefore, medium and low temperature processing is suitable for the production of sweet-scented osmanthus products with health benefits, and high-temperature processing is suitable for the production of sweet-scented osmanthus-based snacks. ‘Boyejingui’ is suitable for low temperature processing, ‘Echengdangui’ is suitable for high temperature processing, and the quality of ‘Wanyingui’ is poor after heat treatment. Processing temperature and varieties should be reasonably selected according to practical demands. This study can provide a theoretical basis for the development of thermally processed products of sweet-scented osmanthus.

Penicillium expansum, a common spoilage organism in postharvest fruits, can cause fruit decay and deterioration and endanger human health. It is of great significance to investigate the antimicrobial mechanism of the antimicrobial peptide from Paenibacillus ehimensis on P. expansum spores. The antimicrobial activity of the antimicrobial peptide against P. expansum spores was determined by using the two-fold dilution method as well as measuring the time-killing curve. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to evaluate the effect of the antimicrobial peptide on the ultrastructure of P. expansum spores. The effects of the antimicrobial peptide on the cell membrane and reactive oxygen species (ROS) accumulation of P. expansum were analyzed by fluorescence probes. The results showed that the minimum inhibitory concentration (MIC) of the antimicrobial peptide against P. expansum spores was 3.5 AU/mL. The spore germination rate was significantly decreased by 28.30%, 84.57% and 100% by the antimicrobial peptide at concentrations of 0.5 MIC, 1 MIC and 2 MIC compared with the blank control (P < 0.05). After treatment with the antimicrobial peptide, the spores appeared seriously sunken, the intracellular contents were leaked out, and the morphology and structure were changed. The antimicrobial peptide damaged the cell wall of P. expansum, resulting in the leakage of alkaline phosphatase. The antimicrobial peptide depolarized the cell membrane potential in a dose-dependent manner, and increased the cell membrane permeability, leading to K+ leakage. The fluidity of the cell membrane was increased, which in turn resulted in a significant decrease in DPH fluorescence intensity (P < 0.05). The integrity of the cell membrane was damaged by the antimicrobial peptide, so the fluorescence intensity of SYTOX-Green and the contamination rate of PI were increased. Moreover, the antimicrobial peptide at 1 MIC and 2 MIC increased the fluorescence intensity of DCFH-DA significantly (P < 0.05) and resulted in ROS accumulation, which affected the physiology and metabolism of P. expansum spores. This study indicated that the target sites of the antimicrobial peptide against P. expansum spores were mainly the cell membrane and ROS metabolism.

In order to explore changes in the milling quality of reasonably well milled rice with different grain shapes, the bran degree, milling degree and broken rice rate of short-grained (‘Jihong 6’), medium-grained (‘Daohuaxiang’) and long-grained (‘Yexiangyoulisi’, ‘Yexiang’ for short) brown rice were measured after milling at different temperatures and for different periods. The results showed that the bran degree decreased exponentially with an increase in milling pressure for ‘Jihong 6’ and ‘Daohuaxiang’ and an increase in milling time for ‘Yexiang’. For reasonably well milled rice with bran degree from 7.0% to 2.0%, as specified by China’s national standard GB/T 1354–2018, the percentage change in milling degree of ‘Jihong 6’, ‘Daohuaxiang’ and ‘Yexiang’ were approximately 5.03%, 2.98% and 0.18%, respectively, indicating that the milling degree of reasonably well milled rice did not change more significantly with increasing grain length. The broken rice rates of ‘Daohuaxiang’, ‘Jihong 6’ and ‘Yexiang’ increased by 5.32, 0.25 and 0.21 percentage points, respectively, and the white rice yields decreased by 1.38, 2.74 and 0.21 percentage points, respectively. The change in broken rice rate of ‘Yexiang’ for reasonably well milled rice was the smallest. The broken rice rates of ‘Daohuaxiang’, ‘Jihong 6’ and ‘Yexiang’ at bran degree of 0.10% increased by 10.36–4.77, 1.85–1.60, and 10.05–9.84 percentage points, respectively compared with those at bran degree from 7.0% to 2.0%, and the white rice yields decreased by 4.19–2.81, 7.02–4.28 and 10.65–10.44 percentage points, respectively. So, the effect of changes in broken rice rate at bran degree of 0.10% on white rice yield was more pronounced. ‘Daohuaxiang’ with bran degree of 2.10%–2.45% met germ retention rate of less than 20% for high-quality japonica rice specified in the national standard, while ‘Jihong 6’ and ‘Yexiang’ with bran degree from 7.0% to 2.0% did not meet this requirement. At bran degree from 7.0% to 2.0%, the whiteness of ‘Daohuaxiang’, ‘Jihong 6’ and ‘Yexiang’ increased by 6.65, 2.80 and 2.69 percentage points, respectively. There was no significant regular change in the breaking strength of the three rice varieties. The bran degree had a significant correlation with the degree of milling, whiteness and germ retention rate in reasonably well milled rice. As observed by scanning electron microscopy (SEM), the difference in thickness between the dorsal and ventral regions of ‘Yexiang’ was the smallest. When the bran degree was about 2.00%, the ventral aleurone layer of the three types of rice was almost entirely removed, while much of the aleurone layer was remained in the dorsal part. When the bran degree was about 0.10%, a small amount of the dorsal aleurone layer was retained for ‘Daohuaxiang’ and ‘Jihong 6’, while the dorsal aleurone layer of ‘Yexiang’ was completely removed. Therefore, the milling degree required for uniform whitening of brown rice and the processing quality vary with cultivar and grain shape.

In order to investigate the intrinsic relationship between protein characteristics and quality changes during the hot air drying of shrimp, Penaeus vannamei was dried by hot air at 55 ℃ after being boiled in 3% salt solution for 2 minutes. We studied changes in the microstructure and quality of shrimp, and systematically investigated changes in the oxidative degradation degree, intramolecular valence bonds, and secondary and tertiary structure of protein. The results showed that the drying treatment gradually decreased the L*, a* and b* values of shrimp, and changed the texture characteristics, and the hardness, adhesiveness and chewiness were increased to 344.78 N, 45.01 mJ and 116.50 mJ at the end of drying, respectively. In addition, oxidative denaturation and degradation of proteins occurred; the total sulfhydryl content decreased to 0.36 μmol/g at the end of drying, while the carbonyl content increased to 2.03 nmol/mg protein, and the trichloroacetic acid (TCA)-soluble peptide content increased to 0.91 μmol/g. The protein structure was significantly changed; the relative contents of ionic and hydrogen bonds decreased, the relative contents of hydrophobic and disulfide bonds increased, the secondary structure was transformed from α-helix to β-fold, β-turn and random coil, the intensity of tryptophan fluorescence decreased, and the tertiary structure was also changed. Pearson correlation analysis showed that the color changes were mainly related to protein oxidation and protein degradation and denaturation significantly affected the textural properties of shrimp. This study can provide theoretical support for further improving the quality of dried shrimp products.

In this study, the relationship between the formation of acrylamide (AA) and that of 5-hydroxymethylfurfural (5-HMF), as well as the correlation with the content of α-dicarbonyl compounds as intermediate products in French fries were studied using Pearson correlation analysis and principal component analysis (PCA), and the correlation between the formation of AA and 5-HMF and the sensory score, color, water content and oil absorption of French fries was also discussed. The results showed that with an increase in frying time or temperature, the contents of AA, 5-HMF and α-dicarbonyl compounds in French fries increased significantly, water content decreased, and oil absorption increased gradually. In addition, lightness (L* value) and yellowness (b* value) tended to decrease, while redness (a* value) tended to increase. There was a significantly positive correlation between AA and 5-HMF contents under the different conditions tested. Moreover, AA and 5-HMF contents showed a significantly positive correlation with the content of α-dicarbonyl compounds and oil absorption, but a significantly negative correlation with water content, L* value and b* value. AA content was positively correlated with a* value. It was found that the results of the PCA model were consistent with the linear curves of the contents of AA, 5-HMF and α-dicarbonyl compounds versus frying temperature and time. Frying for 5 min at 170 ℃ not only ensured the best sensory quality of French fries, but also helped to reduce the formation of hazardous substances.

In this paper, a simulation method based on material-drying oven integration was developed for the hot air-drying process of Lentinus edodes. First of all, the drying characteristics were investigated under different drying conditions, and drying kinetic models were obtained at different air temperatures, relative humidities (RHs) and air flow rates. Then, drying kinetic derivative models to predict the drying process under different working conditions were obtained and used to calculate water evaporation rate, and the rate of water evaporation was introduced into the heat and mass transfer equations to develop mathematical models based on material-drying oven integration. Using the models, the pattern of temporal changes in air temperature, RH and air flow rate at any position inside the oven and moisture ratio (MR) was obtained. Finally, the drying characteristics were worked out using the integrated models. Overall, significant non-uniformity occurred during the drying process. As drying proceeded, non-uniformity decreased. In the direction of air flow, non-uniformity was more significant at positions closer to the oven’s top and bottom. In the transverse direction, non-uniformity was more significant at positions closer to the middle. In summary, the simulation method for hot air-drying of Lentinus edodes is meaningful for guiding the structural design of the drying chamber, the optimization of the drying process and the improvement of the product quality.

In this study, experiments were conducted to investigate the effect of moisture distribution during pre-drying on the microstructure and textural quality of hot air-vacuum freeze dried peach slices. The moisture distribution during the hot air pre-drying process at different temperatures (40, 60 and 80 ℃) and the product temperature during heating were monitored. Three levels of dry-basis moisture content (7, 6 and 5 g/g) were selected as moisture conversion points for each temperature. The color, shrinkage rate, microstructure, pore distribution, textural properties and hygroscopicity of peach crisps were measured. The results showed that drying temperature had a great impact on the moisture distribution during the pre-drying process, but the overall trends of moisture mobility were consistent among the different drying temperatures. The lower the moisture content of the pre-dried sample, the closer the color of the final dried sample to that of the fresh sample. The color of the sample dried at 40 ℃ with a moisture conversion point of 5 g/g was the closest to that of the fresh sample. Drying time had a greater effect on the shrinkage rate than temperature. It took longer to dry peach slices to the same moisture conversion point at 40 ℃ than 60 and 80 ℃. The sample shrank distinctly during both pre-drying and combined drying. There was a significant difference in the pore structure between the freeze-dried and combined dried samples. The sample with a moisture conversion point of 5 g/g had the most heterogeneous pore structure. The average hardness value of the hot air-vacuum freeze dried sample increased by 52.11% compared with that of the freeze-dried sample. The lower the moisture content of the pre-dried sample, the higher the hardness value of the hot air-vacuum freeze dried sample. This study showed that hot air pre-drying can effectively control the crunchiness and hardness of peach crisps. The decrease in the hygroscopicity of the hot air-vacuum freeze dried sample compared with the vacuum freeze dried one may be related to the structure changes during the pre-drying process. In summary, hot air-vacuum freeze drying is conducive to improving the texture quality and storage stability of peach crisps than vacuum freeze drying.

In this study, chickpea starch was treated with atmospheric pressure steaming, atmospheric pressure boiling, high pressure steaming or high pressure boiling for 20 min. The effects of the four common heat treatment methods on the ordered crystal structure, particle structure and physicochemical properties of chickpea starch were investigated through the determination of physicochemical parameters, X-ray diffraction spectroscopy, infrared spectroscopy and microstructure observation. Results showed that the granular structure of chickpea starch was completely preserved after steaming treatment. It exhibited birefringence under polarized light and its crystal structure was still type CA. After boiling at atmospheric and high pressure, the relative crystallinity decreased from 31.4% to 25.5% and 20.4%, respectively. Moreover, the peak viscosity, though viscosity, final viscosity, breakdown value and setback value decreased. The degree of retrogradation of chickpea starch after heat treatments was as follows in decreasing order: high pressure steaming > atmospheric pressure steaming > native starch. The granular structure and crystal structure of chickpea starch were damaged seriously after boiling treatment. The relative crystallinity was 5.9% and 3.6% after boiling at atmospheric and high pressure, respectively, and the viscosity decreased. The treatment starch showed no obvious retrogradation after gelatinization. In addition, the crystal structure of chickpea starch was damaged more seriously after high pressure treatment, while there was no significant difference in granular morphology, birefringence or functional groups between the samples treated by atmospheric and high pressure. The results of this research can provide a theoretical basis and guidance for the development and utilization of chickpea starch and are of significance for enriching the basic theory of chickpea starch.

In order to improve the processing quality of wheat, newly harvested wheat was treated with glow discharge cold plasma. The changes in the physicochemical properties of wheat flour and the rheological properties of wheat flour dough after the treatment were studied, and the molecular mass distribution and secondary structure of wheat flour proteins were furthermore analyzed. The results showed that the gluten index of wheat was significantly increased after cold plasma treatment with oxygen or argon as the gas source. Dough development time and stability time were improved, and the mixographic parameters midline integral at 8 min (MTxI) and midline width at 8 min (MTxW) were significantly increased (P < 0.05), while weakening slope (WS) was significantly decreased (P < 0.05). The content of macromolecular polymeric storage protein fraction F1 was increased, and the ratio between macromolecular polymeric storage protein fraction F1 and small-molecule polymeric storage protein fraction F2 was significantly increased (P < 0.05). The protein secondary structure was transformed from β-sheet and β-turn to more ordered intermolecular β-sheet. In conclusion, glow discharge cold plasma treatment changed the molecular mass distribution and secondary structure of wheat storage proteins, significantly enhanced the elasticity and mixing tolerance of dough, and improved the tensile resistance of dough, thereby enhancing the processing quality of wheat to some extent.

Three-dimensional food printing (3DFP) is an efficient way of food processing in line with the future lifestyle. As a delivery system, hydrogel has become a research hotspot because of its remarkable characteristics such as directed delivery. The purpose of this study was to explore the effects of 3DFP on the structure, physical properties and functions of hydrogels containing methylcellulose (MC), chlorogenic acid (CA) and hyaluronic acid (HA) for the purpose of revealing the printability and applicability of hydrogels in 3DFP processing. Texture properties, rheological properties, microstructure, embedding rate and digestive properties of the 3D printed products were measured. The results showed that the best CA-loaded hydrogel system for 3DFP processing consisted of MC, HA and CA at a mass ratio of 8:0.5:0.5. Its printed product showed the smallest width deviation (13.40%), the highest hardness, the maximum elasticity, and the minimum adhesiveness, had compact structure and uniform porosity, was not easy to collapse, and had good supportability and the best printing moldability. 3DFP well optimized the physical structure of hydrogel without changing its chemical properties. The embedding rate of CA was 22.09 percentage points higher than that before 3D printing. In simulated gastrointestinal digestion test, the release rate of CA from the printed product was significantly higher than that of the unprinted samples, showing a good sustained release effect, and the in vitro release of CA was fitted to the Ritger-Peppas model. These results showed that the hydrogel system had good printability and applicability, and 3DFP could significantly improve the targeted release of CA loaded in hydrogel.

The study investigated the effect of different extrusion parameters: temperature, material moisture of raw material, and screw speed on the conformation of soybean protein. After being extruded, soy protein isolate (SPI) was measured for protein solubility, zeta potential, particle size, protein subunits and protein secondary structure. Additionally, the formation mechanism of fibrous soybean protein was uncovered. The results showed that with an increase in extrusion temperature, the natural structure of SPI was destroyed, the internal groups were exposed, and the content of disulfide bonds increased, promoting the formation of protein aggregates. Too high or too low temperature was not conducive to the formation and stability of protein aggregates. At too low or too high raw material moisture content, a relatively complete extrudate was difficult to form at the extrusion mouth, while at raw material moisture contents of 20%–22%, the extrudate was in the best state due to the protective effect of water, and a uniform SPI aggregate was formed. Low screw speed (below 130 r/min) could lead to insufficient mechanical energy input, so that the protein was not completely denatured and depolymerized. While at high screw speed (above 140 r/min), the effect of high shear force promotes the destruction of the original natural structure of proteins, resulting in the formation of large protein aggregates. In summary, under appropriate extrusion conditions, the optimal extrudate quality can be obtained, while extreme extrusion conditions make extrusion molding difficult or result in nonuniform texture. This study can provide a theoretical basis for optimizing the quality of fibrous soybean protein.

This study was executed in order to investigate quality deterioration caused by lipid oxidation during the frozen storage of Acipenser sinensis. Fish pieces were stored at −18 ℃ for 24 weeks after being frozen using a freezer (−20 or −50 ℃) or liquid nitrogen (−80 or −110 ℃). The central temperature, fat and free fatty acid (FFA) contents, fatty acid composition, peroxide value (POV), thiobarbituric reactive substance (TBARS) value, and fluorescent compound content were measured and the microstructure of muscle fibers was also observed during the storage period for the purpose of evaluating the influence of freezing methods on lipid oxidation and muscle microstructure in Acipenser sinensis during frozen storage. The results showed that with increasing storage time, the fat and polyunsaturated fatty acid (PUFA) contents of the four fish samples decreased, while POV, TBARS value, and the contents of FFAs, saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs) and fluorescent compounds increased. The gap between muscle fibers increased, which was accompanied by breaking of myofibrils. In addition, the contents of fat and PUFAs in liquid nitrogen frozen samples were significantly higher than those in freezer frozen ones (at the end of storage, the freezer frozen sample frozen at −20 ℃ contained 7.89% of fat compared to 9.13% for the liquid nitrogen frozen one at −80 ℃), while POV, TBARS value, and the contents of FFAs, SFAs, MUFAs and fluorescent compounds were significantly lower than those in freezer frozen samples (P < 0.05), and the muscle fiber structure was more complete. The above results indicated that liquid nitrogen frozen alleviated the degree of myofibrillar damage and lipid hydrolysis in Acipenser sinensis during frozen storage, thereby reducing the speed of lipid oxidation.

Objective: To investigate the protective effect of Rosa roxburghii Tratt. juice (RRTJ) fermented by Lactobacillus paracasei SR10-1 against ulcerative colitis (UC) in mice. Methods: SR10-1 fermented Rosa roxburghii Tratt. juice was prepared in the laboratory. A mouse model of UC induced by dextran sulfate sodium (DSS) was created. The experiments were designed using five groups, i.e., blank control, DSS-induced model, positive control (mesalazine), lactic acid bacteria fermented RRTJ (LAB-RRTJ) and RRTJ. Disease activity index (DAI) score, visceral organ indices, colon length, colon pathological changes, the levels of inflammatory factors including interleukin (IL)-1β, IL-6, IL-10, IL-17A, tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), the levels of oxidative stress indicators including malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH), the activity of myeloperoxidase (MPO), and the expression levels of gut barrier-related genes (claudin-3, ZO-1 and MUC2) were analyzed in UC mice. Results: Compared with the DSS-induced model group, LAB-RRTJ significantly reduced the DAI score (P < 0.05), and relieved diarrhea, bloody stools, colonic atrophy and pathological changes of mice. In addition, the colon length was significantly increased (P < 0.001), and the spleen and liver indices were significantly decreased (P < 0.001 and P < 0.05, respectively). The levels of IL-1β, IL-6, IL-17A, TNF-α, and IFN-γ were significantly decreased (P < 0.05), while the level of IL-10 was significantly increased (P < 0.05). The levels of MDA and MPO were significantly decreased (P < 0.05), the activities of SOD and GSH were significantly increased (P < 0.001 and P < 0.05), and the expression levels of claudin-3, ZO-1 and MUC2 were significantly increased (P < 0.01). Conclusion: Fermented Rosa roxburghii Tratt. juice with Lactobacillus paracasei SR10-1 could reduce intestinal damage in UC mice by improving inflammatory responses and regulating the level of oxidative stress and intestinal barrier function.

Objective: To investigate the effect of hawthorn procyanidins (HPC) on lipid metabolism and its mechanism by regulating the AMP-activated protein kinase/sterol regulatory element binding protein-1c (AMPK/SREBP-1c) signaling pathway. Methods: Sixty rats were randomly divided into six groups (n = 10) blank control (BC), hyperlipidemia model (HM), low-, medium-, and high-dose HPC (HPC-LD, HPC-MD, and HPC-HD) and fenofibrate positive control (FP). The contents of triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) in the serum and liver homogenate were measured by commercial kits. Hematoxylin eosin (HE) staining was used to observe hepatic histopathological changes. The mRNA expression levels of AMPK, SREBP-1c, glycerol-3-phosphate acyltransferase-1 (GPAT1), acetyl CoA carboxylase (ACC), fatty acid synthase (FAS), carnitine palmitoyltransterase-1 (CPT1) and peroxisome proliferator activated receptor γ coactivator-1α (PGC-1α) in the liver were measured by quantitative real-time polymerase chain reaction (PCR). Western blotting was used to detect the protein expression of p-AMPK, SREBP-1c, GPAT1, ACC, FAS, CPT1 and PGC-1α in the liver. Results: After seven weeks of feeding on a high-fat diet, body mass, liver mass and liver index significantly increased compared with the control group fed on a basal diet (P < 0.05 or < 0.01). Compared with the HM group, the contents of TG, TC and LDL-C in serum and liver homogenate in the HPC-HD and FP groups significantly decreased, and the content of HDL-C significantly increased (P < 0.01); the effect of HPC on lipid content in serum and liver homogenate was dose-dependent. After prophylactic intervention with HPC, the steatosis of hepatocytes was gradually improved with an increase in the dosage of HPC. Compared with the HM group, the AMPK mRNA expression and p-AMPK protein expression in liver tissues in the HPC-HD and FP groups significantly increased (P < 0.01), and the mRNA and protein expression of SREBP-1c, GPAT1, ACC and FAS significantly decreased (P < 0.01), and the mRNA and protein expression of CPT1 and PGC-1α significantly increased in the liver (P < 0.01). Conclusion: HPC can effectively improve lipid metabolism in hyperlipidemic rats, which may be related to the regulation of the AMPK/SREBP-1c signaling pathway.

Delaying aging has become a hot spot of social concern and research. Our previous studies have shown that ripe Pu-erh tea can delay aging in mice by regulating the intestinal flora, but the metabolites in response to endogenous substances in mice are not clear. In this paper, the Morris water maze test was used to detect learning and memory capacity in control, D-galactose-induced aging, and ripe Pu-erh tea-treated mice. Non-targeted metabolomics was used to detect metabolites in the brain tissue and serum of mice from each group for the purpose of exploring the anti-aging effect of ripe Pu-erh tea on D-galactose-induced aging mice, screening differential metabolites among the three groups and analyzing the related metabolic pathways. The results showed that ripe Pu-erh tea improved learning capacity, and regulated 26 differential metabolites in the brain tissue of aging mice, mainly involved in the glycerophospholipid metabolism, vitamin B6 metabolism, histidine metabolism and purine metabolism pathways, among which the glycerophospholipid metabolism and histidine metabolism pathway were the most significant. A total of 11 differential metabolites were identified in serum, mainly involved in the metabolism of vitamin B6 and arachidonic acid, among which vitamin B6 metab olism pathway was the most significant. After the intervention with ripe Pu-erh tea, the contents of glycerophospholipid metabolites including phosphatidylcholine [PC (20:5/20:4)], phosphatidyl ethanlamine [PE (22:2/14:0)], phosphatidylserine [PS (20:5/18:1)] and lysophosphatidylcholine [LysoPC (18:2)], the histidine metabolite carnosine, and the vitamin B6 metabolite pyridoxal 5’-phosphate were significantly increased in aging mice. These results suggest that ripe Pu-erh tea can delay aging by regulating lipid and amino acid metabolism.

Objective: In order to explore the effects of Lonicera caerulea berry polyphenols (LCBP) on immunity and intestinal flora in immunosuppressive mice. Methods: Thirty-two mice were randomly divided into a blank control group, a model group, a low-dose LCBP group and a high-dose LCBP group. Cyclophosphamide at 80 mg/(kg mb·d) was injected intraperitoneally after 17, 19 and 21 d of oral administration. Immune organ indices, routine blood biochemical indexes, intestinal microbial diversity and distribution, and the level of short chain fatty acids in colonic contents were investigated and colonic histopathology was examined by hematoxylin-eosin (HE) staining. Results: Compared with the model group, spleen and thymus indexes in the high-dose LCBP group significantly increased (P < 0.01). Also, the number of white blood cells, lymphocytes and platelets increased (P < 0.05), and so did the number of red blood cells and neutrophils (P < 0.01). LCBP increased the relative abundance of Firmicutes, Epsilonbacteraeota, Proteobacteria, Patescibacteria, Actinobacteria and Cyanobacteria in the intestinal tract of immunosuppressive mice and the concentrations of fecal short-chain fatty acids (SCFAs). Conclusion: LCBP can increase the type of intestinal flora, regulate the structural distribution of intestinal flora, alleviate intestinal injury and enhance immune function in immunosuppressive mice.

Objective: To explore the protective effect of the freeze-dried fruit powder of Phyllanthus emblica L. (PEFP) against acute and chronic hyperuricemia (HUA) and liver and kidney injuries in mice. Methods: Mouse models of acute and chronic HUA were established by intraperitoneal injection of hypoxanthine and potassium oxazinate, respectively. Meanwhile, PEFP at 75, 150 and 300 mg/kg mb were orally given to the mice in the intervention group for seven days. The levels of uric acid (UA), creatinine (CRE), blood urea nitrogen (BUN), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the serum, and the activities of xanthine oxidase (XOD) and adenosine deaminase (ADA) in the serum and liver were detected. Liver and kidney indexes were calculated, and the pathological characteristics of liver and kidney tissues were observed by hematoxylin and eosin (HE) staining. Results: Compared with the model group, PEFP at 150 and 300 mg/kg mb significantly reduced the liver and kidney indexes (P < 0.01) and lowered serum UA, BUN, CRE, and AST levels in mice with acute hyperuricemia (P < 0.05 or P < 0.01). PEFP at 75, 150 and 300 mg/kg mb significantly inhibited serum and liver XOD and ADA activities (P < 0.01), and PEFP at 300 mg/kg mb lowered serum ALT levels in mice with acute hyperuricemia (P < 0.01). Meanwhile, all three doses of PEFP significantly reduced the liver and kidney indexes (P < 0.01), lowered serum UA, BUN and ALT levels (P < 0.01), and inhibited serum and liver XOD activities and serum ADA activity in mice with chronic hyperuricemia (P < 0.01). PEFP at 150 and 300 mg/kg mb lowered serum CRE and AST levels and liver ADA activity (P < 0.01). PEFP ameliorated the pathological changes of the liver and kidney in mice with acute and chronic hyperuricemia. Conclusion: PEPP can effectively decrease serum UA levels in mice with acute and chronic hyperuricemia, which may be related to the inhibition of XOD and ADA activities in the serum and liver, and the promotion of renal uric acid excretion, and can also exert renal and hepatoprotective effects.

objective: To investigate the protective effect of Lanzhou lily polysaccharide (LLP) and aerobic exercise (AE) on the kidney in a rat model of diabetic mellitus (DM). Methods: Fifty Wistar male rats are randomly divided into a normal control group (n = 10) and a DM model group (n = 40). The rats in the diabetic group were intraperitoneally injected with streptozocin (STZ, 60 mg/kg mb), whereas those in the control group were given the same amount of 0.1 mol/L citrate buffer solution at pH 4.2. After successful induction of diabetes, the diabetic rats were divided into a DM control group, a DM + AE group, a DM + LLP group, and a DM + LLP + AE group, each containing 10 animals. LLP was orally given at a dose of 150 mg/kg mb on a daily basis, and the same amount of distilled water was used as control. The rats in the DM + AE and DM + LLP + AE groups were subjected to swimming training for six weeks, and allowed to recover for 24 h after the last exercise. Afterwards, all rats were sacrificed and left ventricular blood was collected for biochemical testing. Bilateral kidneys were excised for histopathological observation. Results: Compared with the DM group, fasting blood glucose (FBG) in the DM + LLP + AE group significantly decreased (P < 0.05), serum insulin (INS) concentration significantly increased (P < 0.05), and serum total cholesterol (TC), triglyceride (TG), serum creatinine (SCr) and blood urea nitrogen (BUN) significantly decreased (P < 0.05). Moreover, the activity of superoxide dismutase (SOD) in the kidney increased significantly (P < 0.05), the content of malonaldehyde (MDA) decreased significantly (P < 0.05), and the structure and morphological characteristics of the renal tissue were improved. Western blot showed that the renal expressions of Bax/Bcl-2 and caspase-3 were significantly reduced in the DM+ LLP + AE group compared with the DM group (P < 0.05). Conclusion: Lanzhou lily polysaccharide combined with aerobic exercise can reduce FBG, increase insulin secretion, effectively reduce blood lipid levels, increase the activity of antioxidant enzymes in the kidney tissue of diabetic rats, improve and restore the structure and morphological characteristics of the kidney tissue, and significantly inhibit the apoptosis of kidney cells in diabetic rats.

This study was conducted to investigate the regulatory mechanism of reactive oxygen species (ROS) on the glycolysis pathway of bovine muscle and its impact on meat tenderness at the early stage of postmortem cold storage. Fresh beef was treated with hydrogen peroxide (H2O2) as a major ROS, N-acetyl-L-cysteine (NAC) as an ROS scavenger, or physiological saline as a control before being stored at 4 ℃. After 0.5, 6, 12, 24, and 48 hours, the glycolysis level and tenderness indices were assessed. In addition, tandem mass tag (TMT)-labeled quantitative proteomics was used for protein identification and quantitative analysis of the samples after 24 hours and for screening of differential proteins in the glycolysis pathway. The findings showed that the glycolysis level increased significantly in the H2O2-treated group, and glycogenolysis and lactic acid accumulation were significantly higher than those in the other two groups (P < 0.05). In contrast, the glycolysis process was significantly suppressed by NAC treatment. The H2O2-treated group reached the ultimate pH after 12 hours, 12 and 36 hours earlier than the control and NAC groups, respectively. The shear force of the H2O2-treated group reached its maximum after 12 hours, and the myofibrillar fragmentation index (MFI) was significantly greater than that of the other two groups after 6–48 hours (P < 0.05), indicating that a higher ROS level can accelerate the tenderization of bovine muscle by enhancing the glycolysis capacity during postmortem refrigeration. Totally eight up-regulated proteins and two down-regulated proteins in the glycolysis pathway were identified in the H2O2-treated versus control groups after 24 hours of refrigeration. Among these proteins, the up-regulated core proteins of phosphoglycerate mutase (PGAM), enolase (ENO), and pyruvate dehydrogenase E1 subunit beta (PDHB) coordinated with the down-regulated pyruvate dehydrogenase E1 subunit alpha (PDHA) to accelerate the glycolysis process. In conclusion, ROS can speed up glycolysis and consequently improve meat tenderness by regulating the expression of key proteins in the glycolysis pathway.

To investigate the effect of pre-cooking treatment on the quality of swimming crab (Portunus trituberculatus) meat during frozen storage, the differences in the quality of group C (control without any treatment), group H-F (heating followed by frozen storage) and group F-H (frozen storage followed by heating) during 180 d storage at −20 ℃ were evaluated in terms of their color difference, water-holding capacity (WHC), pH, total volatile base nitrogen (TVB-N) content, total viable count (TVC), and protein composition and microstructure. The results showed that the whiteness and WHC of the three groups decreased with storage time. The pH of group C decreased first and then increased, while the pH of the other two groups showed the opposite trend and then remained steady. The TVB-N content and TVC of all groups showed an overall upward trend. The TVB-N content and TVC of group H-F were (21.12 ± 0.58) mg/100 g and (4.03 ± 0.17) (lg(CFU/g)) after 180 d, respectively, which were significantly lower than those of group F-H. The microstructure of crab muscle in group C changed from clear and ordered to fuzzy and disordered during the frozen storage process, while pre-cooked crab meat maintained a better morphology. Besides, the results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) suggested that crab meat proteins in the three groups were degraded to different degrees during storage, which was more pronounced in group F-H than in group H-F. Therefore, pre-cooking treatment could efficiently reduce the quality deterioration of crab meat during frozen storage, which could provide a reference for subsequent research to improve the frozen storage quality of P. trituberculatus.

In order to explore dynamic changes in the physicochemical characteristics and microbial diversity of modified atmosphere packaged braised chicken during refrigeration, high-throughput sequencing technology and traditional isolation and identification methods were combined to study the physical and microbial changes of modified atmosphere packaged (25% CO2/75% N2) braised chicken during storage at 4 ℃ for 10 days. The results showed that total volatile basic nitrogen (TVB-N) content and total bacterial count increased significantly during storage (P < 0.05). pH decreased significantly in the late storage period (P < 0.05). Thiobarbituric acid reactive substance (TBARS) levels tended to be stable at the end of storage (P > 0.05). These changes were related to the gas composition in modified atmosphere packaging. The microbial species richness of braised chicken was the highest at the early stage of storage, and then decreased gradually. At the initial stage of storage, the relative abundance of Enterobacteriaceae, Acinetobacter and Aeromonas were high. At the middle and late stages of storage, the relative abundance of Weissella and Enterobacter were high. The relative abundance of Weissella, Enterobacter, Lactococcus and Leuconostoc increased gradually during the whole storage period and their growth was dominant. Six species of spoilage organisms were isolated and identified, namely, Lactobacillus curvatus, Bacillus cereus, Bacillus safensis, Serratia liquefaciens, Hafnia sp. and Enterobacter sp., which could be the major causes of the rot of braised chicken under modified atmosphere packaging conditions.

Perillaldehyde is a green and safe natural antibacterial substance extracted from perilla leaves, which is also used as a food additive in food production. In this study, the inhibitory effect of perillaldehyde on Penicillium citrinum, a major pathogen of Chinese bayberry (Myrica rubra), was investigated by minimum inhibitory concentration (MIC), spore germination rate and mycelial growth inhibition assays, and the underlying mechanism was elucidated by studying the mycelial morphology and ultrastructure, cell membrane damage, membrane lipid peroxidation and changes in functional groups. The results showed that the MIC of perillaldehyde on P. citrinum was 120 μL/L. Mycelial growth was completely inhibited by treatment with 120 μL/L perillaldehyde, and the relative conductivity and malondialdehyde (MDA) content increased. Compared with the untreated group, ergosterol, total lipid and chitin contents and mitochondrial adenosine triphosphatase (ATPase) activity decreased by 80.00%, 81.25%, 64.97% and 87.40% in P. citrinum treated with 90 μL/L perillaldehyde. The treatment with perillaldehyde damaged cell membrane permeability and affected the normal physiological function of the cell membrane. By scanning electron microscopy (SEM) and transmission electron microscopy (TEM), it was found showed that the broom-like conidial head of P. citrinum disappeared after perillaldehyde treatment, and the mycelia appeared to be broken and ablated. Moreover, the cell membrane was broken, intracellular contents leaked out, and the cells became shriveled. In addition, the amounts of leakage of soluble protein, soluble sugar and nucleic acid from P. citrinum treated with 120 μL/L perillaldehyde for 5 h increased by 71.20%, 210.93% and 117.31% compared with those before the treatment, which verified cell membrane damage. By using Fourier transform infrared (FTIR) spectroscopy, it was found that the contents of functional groups such as hydroxyl, methyl, aromatic carbon skeleton and benzene ring carbon skeleton in perillaldehyde treated P. citrinum decreased, and internal substances were gradually consumed. In summary, perillaldehyde showed a good antifungal activity on P. citrinum by destroying cell membrane structure, changing membrane permeability, interfering with energy metabolism and destroying protein and genetic material. Perillaldehyde has good research and development prospects as a natural preservative.

Anthracnose, a common postharvest fungal disease of fruits, can cause severe economic losses. A pathogenic strain named FC.006 was isolated from postharvest anthracnose of ‘Browns Wick’ figs by the traditional fungal isolation method. FC.006 was identified as Colletotrichum horii by morphological observation, multigene sequence identification and phylogenetic tree analysis. In order to investigate a biological control method for FC.006, the control effect of the biocontrol agent Bacillus velezensis RD.006 on FC.006 in vitro and infected figs was evaluated. The results showed that the inhibition rate of FC.006 by RD.006 was 85% when co-cultured in vitro for 8 days. RD.006 had good disease control effect on figs infected with FC.006, and significantly increased the expression of the FcPAL, Fc4CL, FcC4H, FcCAT, FcAPX, and FcPOD genes at the early stage after inoculation (P < 0.05). To sum up, C. horii FC.006 can cause fig anthracnose, and Bacillus velezensis RD.006 can effectively control postharvest anthracnose in figs through direct antibiosis and induction of fruit disease resistance.

Fresh hazelnuts were treated by 60Co-γ irradiation (0, 0.25, 0.50, 0.75 and 1.00 kGy) and stored at (4.0 ± 0.5) ℃ for up to three months. Changes in physiological indexes and lipid nutrition were monitored during the storage period. The results showed that irradiation at a dose of 0.25–1.00 kGy delayed the decline in superoxide dismutase (SOD) and catalase (CAT) activity, and reduced the activity of polyphenol oxidase (PPO) in fresh hazelnuts. The irradiation dose of 0.50 kGy was the most effective, and at the end of storage, the respiratory intensity, malondialdehyde (MDA) content and lipoxygenase activity of the irradiated sample decreased by 25.81%, 18.50% and 4.18% compared with those of the non-irradiated one, respectively. However, irradiation had no significant effect on fatty acid composition and content, peroxide value (POV) or acid value (AV). Principal component analysis (PCA) performed on fresh hazelnuts stored for 90 d also showed that 0.50 kGy 60Co-γ irradiation imparted the best storage quality to fresh hazelnuts. These results suggest that 60Co-γ irradiation can delay the senescence and effectively extend the shelf life by affecting the postharvest physiology of fresh hazelnuts.

In this study, the effects of different freezing methods namely air freezing, cryogenic freezing, freezing after dipping in a refrigerating medium consisting of 20% ethanol (V/V), 20% propylene glycol (V/V), 5 g/100 mL trehalose aqueous solution and freezing after dipping in anhydrous ethanol on the quality of sea bass were investigated. The results showed that the freezing rates of refrigerating medium freezing and anhydrous ethanol freezing were 8.20 and 6.25 cm/h, which were 32.80 and 25.00 times as high as that of air freezing, respectively. The microstructure of frozen sea bass showed that the small ice crystals formed between muscle tissues were small, and the muscle fibers were closely arranged. Refrigerating medium freezing was more conducive to maintaining the water-holding capacity (WHC) of muscle tissues and slowing down the migration of immobilized water, and had a significant effect on maintaining the freshness, texture properties and protein thermostability of fish fillets. In summary, refrigerating medium freezing can effectively slow down the quality deterioration of frozen sea bass. The results of this study will provide a theoretical and practical basis for improving the storage quality of frozen aquatic products.

Polyphenol oxidase (PPO) is one of the most important factors affecting the browning of fresh-cut fruit and vegetable products. In this research, the effect of aromatic hydrosol on the activity of PPO and its biological antioxidant effect were studied. Aromatic hydrosol extracted from 12 kinds of aromatic plants by steam distillation all inhibited the activity of PPO. Eight of the 12 aromatic hydrosols had a significant scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation, and 2-phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl (PTIO) radicals. Total antioxidant capacity assay showed that they had strong antioxidant activity. Analysis by electronic nose and gas chromatography-mass spectrometry (GC-MS) showed that terpenoids and aromatic compounds were the major volatile components of aromatic hydrosol. The efficacy of aromatic hydrosol was evaluated in preserving the quality of fresh-cut mushrooms (Agaricus bisporus). The results showed that compared with the control group, the PPO activity in mushrooms treated with aromatic hydrosol was inhibited, and the increase in browning index (BI) was delayed. In addition, total phenol content, hardness, mass loss and total microbial load were effectively controlled. These results indicate that aromatic hydrosol treatment has a positive effect on maintaining the quality of fresh-cut mushrooms.

In order to clarify the effects of precooling treatments on the postharvest storability and neohesperidin metabolism of sweet cherries, forced-air precooling, ice-water precooling, cold storage precooling and ozone ice-water precooling were used to treat ‘Red Agate’ sweet cherries prior to being stored at (0.0 ± 0.5) ℃. The sensory quality, nutritional quality, respiratory metabolism, disease resistance-related enzyme activities, neohesperidin content and related gene expression in sweet cherries were analyzed during storage. In addition, the key indicators for the evaluation of storability and the key regulatory genes of neohesperidin metabolism in sweet cherries were selected by correlation analysis. The results showed that compared with commercial precooling (cold storage precooling), forced-air precooling significantly increased the activities of peroxisome (POD), superoxide dismutase (SOD), catalase (CAT), cinnamic acid-4-hydroxylase (C4H), cinnamyl-alcohol dehydrogenase (CAD) and 4-coumarate:coenzyme A ligase (4-CL), maintained higher fruit hardness, and reduced the disease index, dry fruit stem incidence, and browning index of sweet cherry during storage (P < 0.05), but its effect in promoting neohesperidin synthesis was not significantly different from that of ice water precooling (P > 0.05). VC content, and the activities of C4H, CAD and 4-CL (key enzymes in the phenylpropane metabolic pathway), SOD, PPO and lipoxygenase showed a significant correlation with the sensory quality of sweet cherries, which could be used as key physiological indicators to evaluate the storage stability of sweet cherry. The content of neohesperidin in sweet cherries fluctuated and decreased during storage. Forced-air precooling could promote neohesperidin synthesis by improving the gene expression of LOC110760277, LOC110751411, LOC110757814, QXJJ01001021, LOC110745765 and LOC110756675 and inhibiting the gene expression of LOC110758277 and LOC110771557. These results indicated that forced-air precooling was more effective in improving the storage storability of sweet cherries and promoting neohesperidin synthesis than ice-water precooling, cold storage precooling and ozone ice-water precooling.

Fish soup, a traditional Chinese broth food, is loved by consumers due to its rich nutrition, high digestion and absorption rate, umami and sweet taste, and strong aroma. However, off-flavors can be formed during the processing and storage of fish soup, restricting its industrial development. Off-flavors in fish soup are from a wide range of sources, have complex composition, and are difficult to eliminate. Therefore, it is urgent to understand the formation mechanism of the flavor quality of fish soup (especially off-flavors), identify the factors affecting the flavor quality of fish soup, and establish measures to regulate off-flavors in fish soup. In this context, this article summarizes the formation pathways of fish soup flavor, and systematically discusses the processing factors that affect the flavor quality of fish soup. It clarifies that selecting appropriate processing methods can effectively enhance the characteristic aroma of fish soup and reduce the undesirable odor, summarizes the current methods to remove the fishiness and bitterness of fish soup, and compares their advantages and disadvantages. We hope that this article will provide a theoretical basis for future research to regulate the flavor quality of fish soup and to develop portable fish soup foods.

Soybean is one of the common food allergens and can cause severe allergic reactions. Currently, due to the lack of a definite treatment for soybean allergy, people with soybean allergy have to avoid eating foods containing soybean protein. However, the addition of different food ingredients and complex processing during food production can make it difficult to accurately detect the presence of soybean allergens in some foods. Therefore, researching methods for the detection of soybean allergens in foods is particularly important. This paper focuses on the major allergenic proteins in soybean and their structural properties, and summarizes the current major techniques for the detection of soybean allergens. It is expected that this review will be of significance for effectively avoiding soybean allergy and ensuring the life and health of people with soybean allergy.

β-1,3-Glucanases are enzymes that specifically hydrolyze β-1,3-glycosidic linkages bonds in β-1,3-glucan to generate a range of oligosaccharides or monosaccharides. β-1,3-Glucanases have important potential applications in functional oligosaccharide preparation, fruit and vegetable preservation, biopharmaceuticals, and plant disease resistance. β-1,3-Glucanases belonging to 12 glycoside hydrolase (GH) families have been identified, including GH16, GH17, GH55, GH64, GH81, GH128 and GH132. β-1,3-Glucanases are widely distributed in bacteria, fungi, plants and insects, which exhibit diverse structures and catalytic functions due to differences in sources and sequence evolution. Structural and functional studies of enzymes are the basis for exploring the catalytic mechanism, enzyme properties, and molecular modification. Therefore, this paper reviews the current state of research on the structure, function and application of β-1, 3-glucanases, in order to provide a reference for the basic research and application of β-1,3-glucanases.

Brown adipose tissue (BAT) improves the metabolic level of the body by promoting energy expenditure, which can contribute to the prevention and treatment of metabolic diseases such as obesity and diabetes, and BAT has become a new target for the treatment of metabolic diseases. BAT activity enhancement in the body is a hot topic but also a challenge for researchers, and research and analysis of functionally active factors in foods that regulate BAT can help to develop new nutritional activators. In this paper, we summarize the development and thermogenesis of BAT and thermogenesis-related factors, and review active ingredients in foods that regulate brown fat and their mechanisms of action, and briefly introduce the effects of white adipose tissue (WAT) and BAT on the body’s health. We also discuss recent developments in understanding the role of BAT in regulating energy metabolic balance and various diseases in the body. We hope that the present review will provide a theoretical basis for future development of brown adipose nutritional activators and improvement of individualized healthy dietary management programs in order to prevent and treat various diseases.

Zearalenone (ZEN) is a mycotoxin produced by the Fusarium species, which has various toxic effects. The chemical structures of ZEN and its derivatives are similar to that of estrogen. When ingested by animals or humans, ZEN and its derivatives can lead to disturbance of estrogen balance, thereby harming the reproductive system. Moreover, they can alter gene structure and consequently affect gene expression, and can even cause damage to the immune system, thus weakening the immune response. ZEN is transformed and metabolized into ZEN derivatives during food processing or after absorption by animals and plants, and its toxicity is altered due to structural and physicochemical changes. Studying the toxicity of ZEN and its derivatives as well as their transformation and metabolism in various organisms is important for ensuring food security and mycotoxin toxicity risk assessment.

Type II diabetes mellitus (T2DM) is one of the most prevalent metabolic diseases worldwide and α-glucosidase inhibitors are oral medications that are effective in the prevention and management of T2DM. Food-derived bioactive peptides are potential sources of α-glucosidase inhibitors, which have shown to have hypoglycemic activity and can effectively control postprandial blood glucose by inhibiting α-glucosidase activity, thus intervening and regulating T2DM, and have great prospects in the development of hypoglycemic peptide products. At present, there is no systematic strategy for exploring the structure-activity relationship, safety and bioavailability of food-derived α-glucosidase inhibitory peptides, hampering their research and development. In this paper, we systematically review the structural characteristics, toxicity, allergenicity, and bioavailability (gastrointestinal digestive enzyme resistance, mucus permeability, transit efficiency in small intestinal epithelial cells and liver metabolism) of food-derived α-glucosidase inhibitory peptides that have been successfully identified in recent years. This review is expected to provide a theoretical reference for the rational development of food-derived α-glucosidase inhibitory peptides and the further processing of related functional foods.

Antarctic krill oil is rich in phospholipid eicosapentaenoic acid and docosahexaenoic acid with high bioavailability. It is a high-quality source of ω-3 fatty acids and is a potential substitute for fish oil. However, it is subject to oxidative deterioration, restricting its deep processing and health benefits. The mechanism of oil oxidation, the endogenous and exogenous factors affecting the oxidative stability of Antarctic krill oil including fatty acid composition, lipid composition, endogenous antioxidants (astaxanthin and tocopherol), temperature, oxygen and light, and the methods to control the oxidative stability of Antarctic krill oil including adding antioxidants and microencapsulation are reviewed in this paper. We anticipate that this review will provide a theoretical reference for in-depth research on the high-value utilization of Antarctic krill oil resources and the control of phospholipid oxidative stability.

Dry aging is an effective method to improve the quality and value of meat. Meat quality characteristics such as tenderness and flavor can be significantly improved through a series of biochemical reactions. In recent years, dry-aged beef has gained huge popularity among consumers and research attention due to its unique flavor. However, there are some problems with the dry-aged beef industry, such as large quality differences, high losses during maturation, and high production costs. This article systematically summarizes quality characteristics of dry-aged beef, including flavor, tenderness, safety, color and water-holding capacity (WHC). The mechanism of formation of its characteristic flavor is briefly described. The effects of different dry-aging conditions on beef quality are summarized. New dry aging technologies and value-added ways to reuse the crust are introduced. This article will hopefully provide theoretical guidance for the standardized, efficient and high-value development of the dry-aged beef industry.

In recent years, the incidence of food allergy has continued to rise globally. Food allergy has become a global food safety and public health problem. Currently, avoiding allergens is the best way to deal with food allergy, and food allergen labeling plays an important role in protecting allergic consumers. This paper reviews recent progress in food allergen risk assessment from the perspectives of the establishment of the food allergens list, the soring-out and utilization of national nutrition and diet survey results, and the population threshold for food allergens. Furthermore, the problems existing in China’s food allergen management are discussed. It is expected that this review will provide information for scientific research and a theoretical reference to strengthen the management of food allergens.

The global prevalence of obesity has nearly tripled in the past 40 years and continues to rise at an alarming rate. High fat and high carbohydrate diets can cause gut microbiota disturbance and impairment of intestinal barrier function in obese individuals. Dysbiosis of the gut microbiota and its metabolites crossing the intestinal barrier lead to insulin resistance, imbalance in energy metabolism, reduced fat browning capacity and increased levels of inflammatory factors, which in turn induce chronic diseases such as diabetes, hypertension and cardiovascular diseases. In this paper, the molecular mechanism of obesity mediated by the gut microbiota is systematically elucidated. Based on this, we propose that the intestinal microecology can be regulated by supplementing probiotics and prebiotics or by changing lifestyle and dietary pattern, which in turn will help to prevent and control obesity.

The growth and metabolism of microorganisms is the main cause of meat spoilage. The rapid and nondestructive techniques for detecting microorganisms in meat have attracted more and more attentions. Spectroscopic techniques such as Raman spectroscopy, infrared spectroscopy and spectral imaging show great advantages in rapid and non-destructive detection, but their application in meat spoilage detection has not been timely summarized. Based on an overview of the dominant spoilage organisms and microbial metabolism in meat under different storage conditions, this paper briefly describes the material basis for spectroscopic prediction of meat spoilage. Then, the application of Raman spectroscopy, infrared spectroscopy and spectral imaging technology in predicting the shelf life of meat is summarized. The efficiency of predictive modeling of meat shelf life based on total bacterial count or total volatile basic nitrogen (TVB-N) content and problems existing in this field are highlighted. We anticipate that this review will provide new ideas and theoretical guidance for the development and application of rapid and nondestructive techniques for meat spoilage identification.

Temporal domination of sensations (TDS) is a temporal multidimensional dynamic sensory analysis method. This method provides the evaluators with a list of the attributes of products, and the evaluators obtain dynamic multi-attribute sensory evaluation results by selecting the perceptions they think to be dominant at each moment of tasting. In this paper, the concept and process of TDS and its application in food sensory evaluation are reviewed, and future directions in the improvement of TDS are discussed. We anticipate that this paper will provide new ideas for the development of new food products based on an understanding of the dynamic changes of sensory perception during food consumption.

Egg yolk is rich in nutrition and complex in structure. Its major components are egg yolk granules (EYGs) and egg yolk plasma (EYP). The physicochemical properties and microstructures of egg yolk and its components are greatly affected by different treatments during processing, and in turn affect their functional properties. Therefore, this paper reviews the effects of different treatments including salting, alkali treatment, heat treatment and enzymatic treatment on the physicochemical properties (surface hydrophobicity, oil exudation, and protein solubility) and microstructure of egg yolk as well as EYGs and EYP. In addition, this paper discusses the functional changes of egg yolk and its components after different treatments. We expect this review to provide theoretical support for future research on the physicochemical properties and microstructure of egg yolk components and on their effects on the functional properties of egg yolk components.

Diabetes is a metabolic disease characterized by insulin secretion disorder. When serious, it can cause various complications (cardiovascular and cerebrovascular diseases, cataract and other eye diseases, kidney disease and cancer), bringing a huge economic burden to the society and families and torturing patients. The risk of diabetes is not only related to genes, living pressure and working environment, but also directly related to patients’ lifestyles and dietary habits. An unhealthy diet (high in fat and sugar) can induce the intestinal flora to produce adverse metabolites, which can in turn promote the occurrence and development of diabetes. Intestinal flora imbalance is widespread in the pathogenesis of various types of diabetes. As an important factor influencing the intestinal flora, diet is not only essential to maintain body functions, but also can contribute to intestinal immunity. Regulation of the intestinal environment through diet is expected to be an effective preventive means and auxiliary therapy for diabetes. By synthesizing the existing literature, this article discusses the features of the intestinal flora and the mechanism of the effect of diet-mediated regulation of the intestinal flora on diabetes based on systematic medical theory, and reviews the role scientific diet plays in regulating intestinal homeostasis and immunity and consequently reducing the incidence and complications of diabetes. We hope that this review will provide a basis for early diagnosis and prevention and adjuvant treatment of diabetes.

With the rapid development of the economy and society and the increasing improvement of people’s living standards, people have gained a scientific understanding of the sub-health state of the body. Many foods with functional claims such as supplementing dietary nutrients, maintaining or improving the body’s health status and reducing the risk of disease have emerged on the market. At the same time, as the country has introduced new policies, laws and regulations such as the “Healthy China 2030” plan to support the development of the health industry, the objective need for food functional claims has become increasingly apparent. But our current laws and regulations do not clearly definite the concept of functional foods and its requirements, so the directions of research, production and sale, market recognition and market regulation of functional foods are unclear. In particular, functional foods cannot be discriminated from health foods, which have a legal definition. In the long term, this will not only fail to promote scientific and technological innovations in ordinary foods, but also hinder the healthy development of the health food industry. In this paper, information concerning the definition and requirements of functional foods is collected and sorted out from government official documents, websites, academic journals, and other authoritative media, and the current focuses of research on functional foods in China and abroad are compared by visual analysis of high-frequency keywords. Moreover, this paper differentiates between the requirements for functional foods and those for health foods, and it suggests that top-level design be made for refined classification of functional foods on the market and puts forward suggestions on how to better connect each category with the current system.

Strontium is of great significance to human health and participates in various physiological functions and biochemical effects. It has great prospects in the development of health products and natural medicines. Strontium not only has a protective effect on bone diseases, dental caries and cardiovascular diseases, but also maintains reproductive health. In addition, more and more studies have confirmed that strontium also has many functions such as anti-inflammatory, antioxidant, anti-adipogenesis, anti-cancer, anti-diabetes, pro-angiogenesis and heart protecting functions. In order to provide a theoretical basis for the development of strontium rich foods and the application of strontium in nutrition, this paper reviews the relationship between strontium and calcium, the safety of strontium, and its safety threshold and major physiological functions.

Glycemic index (GI) is a key indicator for evaluating the postprandial glycemic response to carbohydrate foods. A low GI diet can not only help to control appetite and delay hunger, but also benefit weight control and improve glucose and lipid levels in diabetic patients. The development of low GI foods has thus become a hotspot in current food research. At present, the international standard ISO 26642:2010, issued by the International Standards Organization (ISO), is the gold standard for measuring the GI values of foods using human subjects around the world. However, human testing has some disadvantages, such as individual differences may lead to significantly different results, even for the same foods, and it is costly and time consuming, and should be ethical, and it is unsuitable for high-throughput testing of food GI values. For this reason, researchers have successively developed various in vitro models to predict food GI values. This article focuses on reviewing the current in vitro and in vivo methods for predicting the GI values of foods, with a particular focus on their advantages and disadvantages, as well as their future developments. The current paper is aimed to provide new ideas for the development and promotion of low GI foods.