In order to investigate the location where drip channels are formed in fresh pork and to complement the current knowledge about the mechanism of drip loss in meat, 20 pork Longissimus dorsi muscle samples were chosen to measure the relative contents of bound water (P2b), immobilized water (P21) and free water (P22) at 12 h and 24 h post-mortem by low-field nuclear magnetic resonance in this study, and the distance between the myofibrillar and the myocyte membrane (intracellular space) and the distance between the myocytes (extracellular space) at 45 min, 3, 9, 12 h, and 24 h post-mortem. The results showed that P21 and P22 at 24 h post-mortem were respectively significantly lower and higher in the high drip loss group than in the low drip loss group (P < 0.01). The intracellular space at 45 min and the extracellular space at 9 h post-mortem in the high drip loss group were significantly greater than those in the low drip loss group (P < 0.05). The intramuscular space at 45 min post-mortem was positively correlated with drip loss (P < 0.01), explaining 24.8% and 45.3% of the variation in P22 and drip loss at 24h post-mortem, respectively. P22 at 24 h post-mortem was positively correlated with drip loss (P < 0.01), explaining 39.5% of the variation in drip loss. The above results suggest that the contraction of pork myofibrils during rigor can cause the formation of intra- and extracellular drip channels. The intracellular space of myocytes at 45 min post-mortem could explain the variation in free water content and drip loss. Larger intracellular space at 45 min post-mortem results in higher free water content in muscle, higher drip loss and weaker water-holding capacity.

Objective: In order to improve the product quality and to increase the utilization rate of raw and auxiliary materials, beef jerky was prepared from beef shank meat by a quantitative marination process. Methods: The effects of marinade-to-meat ratio, vacuum degree, tumbling time and steaming time on the yield, color, texture and sensory quality of beef jerky were studied to determine the optimal processing parameters. The quality of the beef jerky prepared using the optimized conditions was comparatively evaluated with that prepared using the traditional process. Results: The quantitative marination conditions could significantly affect the yield, color, texture characteristics and sensory quality of beef jerky (P < 0.05), and marinade-to-meat ratio and tumbling time had greater influence than other processing conditions. The optimal processing parameters were as follows: marinade-to-meat ratio 30%, vacuum degree 0.06 MPa, tumbling time 4 h, and steaming time 40 min. Compared with the traditional process, the quantitative marination process could significantly increase the protein content, pH, elasticity, sensory quality and yield of beef jerky (P < 0.05), and reduce L*, a* and b* values, hardness and chewiness (P < 0.05). The samples prepared using the traditional and quantitative marination processes were detected to contain 23 and 47 volatile flavor components, indicating that the latter had a richer flavor with softer odor. Conclusion: The quantitative marination process can be applied to the production of beef jerky to avoid the loss of raw and auxiliary materials and nutrients caused by traditional long-term cooking and consequently to improve the yield, quality and flavor of beef je rky.

There is a folk tradition of producing oil from Cucumis bisexualis seeds. In order to promote the development and utilization of this wild plant resource, in this study, the physicochemical and thermal characteristics of the oil pressed from Cucumis bisexualis seeds were investigated. The results showed that thousand-grain mass (TGM) of Cucumis bisexualis seeds was 6 g with an oil yield of 25%. The acid value (0.37 mg/g) and peroxide value (0.17 g/100 g) of the oil met the national standard for the quality of edible oils. The relative content of unsaturated fatty acids (UFAs) was 86.27% and linoleic acid was the most predominant fatty acid (67.1% of total fatty acids) along with a lesser amount of γ-linolenic acid. Notably, the oil contained high contents of γ-tocopherol (1 614.21 μg/g) and β-sitosterol (186.18 mg/100 g) and consequently had high oxidative stability. At an initial oxidation temperature of 221.6 ℃ (measured by differential scanning calorimetry (DSC)), the oxidative induction time (OIT) of the oil was 263.91, 133.64 and 26.50 min in an oxygen atmosphere under isothermal conditions at 110, 120 and 140 ℃, respectively. The oxidative stability was superior to that of rapeseed oil. Thermogravimetric (TG) analysis indicated that the smoking point of Cucumis bisexualis seed oil was 300–350 ℃, and mass loss began to occur at 300 ℃. It had excellent thermal stability and could be utilized as a potential cooking oil.

In order to develop a new method for crispness evaluation of crisp foods by the measurement of both their mechanical and acoustic properties, three brands of commercial potato chips were used as experimental materials in this study. A test platform was developed, consisting of a texture analyzer and an acoustic emission (AE) system. The mechanical and acoustic signals of potato chips during mechanical compression until fracture were collected continuously and the crispness of potato chips was classified by the peak value of acoustic energy signals and maximum stress. It was found that in the mechanical compression process, many intermediate peaks of stress and AE energy caused by the internal pore ruptures occurred in each sample, followed by maximum peak values of AE energy and stress upon rupture of the whole sample. Both maximum stress and AE energy showed statistical distribution characteristics among samples. Under the experimental conditions of this study, the mean maximum AE energy value was 93.51 mV·ms for brand A, and the average maximum stress was 0.035 MPa. Potato chip crispness was classified by mean maximum stress and AE energy. The crispness of the three brands of potato chips was in the decreasing order: A, B and C. These experimental data show that combined use of mechanical and acoustical measurement is feasible to evaluate the crispness of dried fruits and vegetables.

Hulless barley is rich in phenolic compounds with a variety of biological activities, whose absorption and utilization are helpful for human health. In order to explore the biological effectiveness and antioxidant activity of hulless barley polyphenols, the total phenolic and flavonoid contents, as well as antioxidant activity of Changhei hulless barley at different digestive stages and different fermentation times were measured by simulated in vitro gastrointestinal digestion and colon fermentation, and their bioavailabilities were further analyzed. Meanwhile, the composition of phenolic compounds was determined by high performance liquid chromatography. The results showed that the total phenolic and flavonoid contents, and antioxidant activity were increased, and the bioavailability of hulless barley phenolics was enhanced after in vitro gastrointestinal digestion. Compared with undigested samples, the contents of total phenolics and flavonoids were increased by 92.87% and 13.89% and their bioavailabilities by 93.17% and 14.97%, respectively. The total phenolic and flavonoid contents, as well as antioxidant activity were significantly increased during colonic fermentation from 0 to 30 h (P < 0.05). The highest total phenolic and flavonoid contents of (20.25 ± 2.07) μmol/g md and (0.72 ± 0.11) μmol/g md, respectively were attained at 30 h. Moreover, at this time, the bioavailability of phenolics and flavonoids were improved by 110.14% and 58.70% in comparison to those at 0 h, respectively. However, the bioavailabilities of total phenolics, flavonoids and antioxidant activity were decreased in comparison to those after 30 h. Eighteen phenolic compounds were identified, belonging to the hydroxybenzoic acid, hydroxycinnamic acid and flavonoid classes. The bioavailability of phenolics compounds in hulless barley can be improved by in vitro gastrointestinal digestion and colon fermentation, and colon fermentation can also promote the release of bound polyphenols from hulless barley.

In order to investigate the effect of fermentation with Penicillium chrysogenum on the eating quality, microstructure and physicochemical properties of duck meat, duck meat was sterilized by autoclaving and inoculated with Penicillium chrysogenum for fermentation for 7 days at (27 ± 1) ℃, and ripening for 14 days at 30 ℃. A texture analyzer, a scanning electron microscope (SEM), a transmission electron microscope (TEM), Raman spectroscopy, low-field nuclear magnetic resonance (LF-NMR) and gas chromatograph (GC)-mass spectrometry (MS) were used to evaluate changes in the texture, microstructure, protein conformation, water distribution and volatile components of duck meat. The results obtained showed that the hardness and springiness of duck meat fermented with Penicillium chrysogenum decreased, and the gumminess increased. SEM and TEM results indicated that fermented duck meat had no intact myofibrils with disorderly arrangement and adhesion in the form of particles. Raman spectroscopy showed that the relative content of α-helix in the protein secondary structure of fermented duck meat decreased and the relative content of β-sheet increased, while the relative contents of β-turn and random coil did not reveal any changes. The micro-environmental hydrophobicity of tryptophan and tyrosine residues was significantly enhanced (P < 0.05). LF-NMR showed that the relative contents of bound water and immobilized water were significantly reduced (P < 0.05). GC-MS analysis identified 29 volatile compounds in unfermented duck meat, and 48 volatile compounds in fermented duck meat. Ketones, esters and acids were newly produced volatile compounds. Therefore, Penicillium chrysogenum can be used to produce fermented meat products with specific flavor and texture, which will provide a new idea for the development of fermented duck meat products that are safe to consume.

Freshness is one of the most important quality parameters of salmon, which has a great influence on its processing suitability. In order to explore the potential relationship between salmon muscle proteins and freshness, isobaric tags for relative and absolute quantification (iTRAQ) technique was used to investigate the change of proteins in salmon meat during storage at 0 ℃. Compared with the fresh control group, totally 62 differentially expressed proteins were identified in salmon with different storage times (5, 10 and 15 days). Further bioinformatics analysis revealed that these proteins were mainly enriched in metabolic pathways and the glycolysis/gluconeogenesis pathways. A total of 28 differentially expressed proteins possibly related to freshness changes during storage were selected, of which two were up-regulated at the initial storage stage, but began to degrade with the prolongation of storage time; ten degraded significantly after 5 days of storage, and with the prolongation of storage time, the degradation continued to occur in varying degrees; three did not change significantly after 5 days, but began to degrade after 10 days; 13 did not change significantly within 10 days, but degraded significantly after 15 days, and these proteins were mainly involved in glucose metabolism, muscle twitch, protein skeleton and energy metabolism. These results showed that all these proteins were closely related to changes in salmon freshness, which provide a rationale for understanding the mechanism of freshness changes at different storage time.

In order to find out the effect of microwave pasteurization on the quality of soft-packed Oncorhynchus keta Walbaum fillets, microwave pasteurization of soft packaged fish fillets (6 cm × 10 cm × 1.6 cm) was carried out by using an 896 MHz microwave system. A comparison was performed with traditional water bath sterilization. The cooking loss rate and water contents of raw and sterilized fish fillets were measured, and the color difference, texture, and flavor components were analyzed using a colorimeter, a texture analyzer and an electronic nose, respectively. Compared with the water bath group, the processing time was reduced by 43.62%, the cooking loss rate by 11.53%, and the total color difference by 24.64% but with a significant increase being observed in redness value (a*) (P < 0.05) for the microwave group. Texture profile analysis showed that the hardness of microwave sterilized samples was significantly lower than that of the water bath group (P < 0.05), and the springiness was better than that of the water bath group. The results of electronic nose revealed no significant difference in odorants between the microwave and water bath groups. Therefore, it could be argued that microwave heating did not generate off-odorants. In conclusion, at the degree of thermal treatment adopted in this study, compared with traditional water bath sterilization, microwave pasteurization was superior in maintaining the cooking loss rate, color and texture of Oncorhynchus keta Walbaum fillets. This study provides a practical foundation for microwave pasteurization of fish meat products.

Objective: To investigate the effects of microencapsulation with different wall materials of ovalbumin (OVA), OVA-tea polyphenols (TP), OVA-inluin (IN) and OVA-IN-TP on the stability of pomegranate seed oil. Methods: Spray drying was used to prepare microcapsules, and the microencapsulation efficiency and solubility were measured. The particle size distribution was investigated by a laser particle size analyzer, the microstructure was observed by a fluorescence microscope and a scanning electron microscope, and the antioxidant capacity and storage stability were investigated. Results: The OVA-IN-TP microcapsules had small and uniform particle size and exhibited smooth surfaces without dents or holes, and the microencapsulation efficiency of pomegranate seed oil was up to (94.52 ± 3.19)%. The storage stability test showed that the antioxidant capacity of microencapsulated pomegranate seed oil with OVA-IN-TP was significantly improved (P < 0.05) with enhanced resistance to extreme environments such as light, temperature and humidity. Therefore, OVA-IN-TP had the strongest stability to delay the oxidation of microencapsulated pomegranate seed oil. To sum up, this study provides an effective way to develop and utilize pomegranate seed oil as a rich source of unsaturated fatty acids.

In order to monitor changes in the quality characteristics and shelf life of Decapterus maruadsi oil microcapsules during storage, the hygroscopicity and the retention rate of the core material under different relative humidity (RH) conditions (34%, 58%, 76% and 93%) were studied. In addition, the oxidative stability of fish oil microcapsules stored at different temperatures (4, 20, 40 and 60 ℃) were also analyzed by peroxide value (POV) and thiobarbituric acid (TBA) value. Shelf life prediction models based on the oxidation indexes as a function of storage temperature and time were established by using first-order kinetic model combined with Arrhenius equation. The results showed that the moisture absorption rate was low at 34% RH, and the retention rate of the core material was still over 90% after 14 days of storage. However, the moisture absorption rate at 93% RH was significantly higher than that at 34% RH, while the retention rate of the core material rapidly decreased to 35.28%, even accompanied by the occurrence of agglomeration and stickiness as well as sensory quality deterioration. Furthermore, the shelf life of fish oil microcapsules based on POV and TBA were predicted to be 190.09 and 195.56 days at 4 ℃, 71.02 and 83.45 days at 20 ℃, 23.81 and 23.86 days at 40 ℃, and 6.32 and 7.87 days at 60 ℃, respectively. The prediction models had excellent accuracy and the relative error between the predicted and the measured shelf life was less than 10%. These results indicated that the models with POV and TBA values as the critical quality factors can accurately predict the shelf life of fish oil microcapsules in the temperature range of 4–60 ℃, which provides a theoretical basis for intelligent prediction of the shelf life of Decapterus maruadsi oil microcapsules during storage and circulation.

In this study, rye, black rice and black bean were subjected to extrusion or drum drying, and their physicochemical properties and storage stability were investigated. The aim was to evaluate the effect of the two treatments on the nutrient composition, solubility characteristics, flowability, rheological properties and storage stability of the three kinds of black grains. The results showed that both the treatments significantly decreased the contents of crude fat, starch and anthocyanin (P < 0.05), and improved the solubility (P < 0.05), but they did not markedly change protein contents. After either treatment, the flowability of black rice and black bean did not change noticeably, while that of rye was improved. All samples showed a non-Newtonian fluid shear thinning behavior. During 45-day accelerated storage, the free fatty acid content and peroxide value of each kind of unprocessed grain were higher than those of the drum-dried and extruded counterparts, and all the unprocessed and processed samples showed similar changes in carbonyl value change. Either treatment could alleviate grain quality deterioration caused by lipid oxidation and improve storage stability. Our research results provide theoretical data for developing ready-to-eat black grain products.

Food-borne tyrosine oxidation product (OTP) not only affects the quality and nutritional value of foods, but also has potential harm to the health of the body; but the relevant mechanism is not yet clear. In this study, we investigated the effects of OTP and dityrosine (DT) as an OTP component on redox homeostasis and myocardial function in mice and elucidated the underlying mechanisms. Thirty male C57BL/6 mice were randomly divided into 3 groups: control, OTP and DT groups. The animals in these groups were intragastrically administered with 420 μg/kg mb tyrosine solution, 1 909 μg/kg mb OTP and 420 μg/kg mb DT solution, respectively, for 35 consecutive days. Weekly changes in body mass were monitored during this period. After that, redox homeostasis parameters, antioxidant enzyme activities and mitochondrial energy metabolism in plasma and myocardium were determined. The results showed that compared with the control group, gavage administration of OTP and DT resulted in a significant increase in cardiac index and the levels of myocardial reactive oxygen species (ROS), DT, malondialdehyde, and free fatty acids (P < 0.05), a significant decrease in total antioxidant capacity, acetyl-CoA content, NADH/NAD+ and ATPase levels (P < 0.05), and a significant increase in plasma tumor necrosis factor α, creatine kinase, and lactate dehydrogenase levels (P < 0.05). Real-time polymerase chain reaction (PCR) results showed that compared with the control group, the mRNA expression levels of anti-oxidation-related genes such as Pi3k, Ampk, Nrf2 and Nqo1 and mitochondrial synthesis-related genes such as Pgc1α, Tfam and Pparα in mice in the DT and OTP groups were significantly down-regulated (P < 0.05). In addition, the effects of DT on myocardial oxidative stress and energy metabolism was consistent with that of OTP with no significant difference between them (P > 0.05). The above findings show that OTP and DT can cause myocardial oxidative stress in mice, leading to myocardial injury and energy metabolism disorder. DT is the major component of OTP that plays a key role in inducing myocardial injury.

Phycocyanin (PC) is recognized as a natural food colorant in China, which can be used in the processing of many foods at low temperatures. PC is also an excellent functional pigment-protein complex. Lots of studies have reported that PC could exert a significant antitumor effect and inhibit the proliferation and migration of non-small cell lung cancer (NSCLC) cells. To get insights into the antineoplastic mechanism of phycocyanin in NSCLC cells, we performed high-throughput miRNA sequencing (miRNA-seq) to analyze the miRNA expression in A549 cells after undergoing phycocyanin treatment. The results indicated that both known and novel predicted miRNAs were sequenced successfully. Totally 136 differentially expressed miRNAs were selected by statistical analysis, including 74 up-regulated and 62 down-regulated miRNAs. Based on their expression levels, these 136 miRNAs could be clustered into 4 patterns. The quantitative real-time polymerase chain reaction (qPCR) validation results were consistent with the miRNA-seq results. Moreover, gene ontology (GO) annotation and functional enrichment analysis showed that cell proliferation related proteins such as PAK4, MAPK13 and RASSF10 were predicted as the potential novel targets of some important miRNAs, playing significant roles in the inhibitory effect of PC on NSCLC cells. Instead of traditional mRNA-seq, this study focused on investigating miRNAs involved in the inhibitory effect of PC on NSCLC cells, which will provide a theoretical foundation for the utilization of antineoplastic ingredients in functional foods and the targeted treatment of NSCLC.

Objective: Peptides from Antarctic krill (AKP) were isolated from an enzymatic hydrolysate of Antarctic krill powder to explore its effect and underlying mechanism on fracture healing in mice. Methods: Female C57BL/6 mice underwent surgery for open fracture of the right tibia and were randomly divided into model control, low-dose (200 mg/kg mb) and high-dose (400 mg/kg mb) AKP groups. At 5, 10 and 21 days after surgery, samples were taken to dynamically analyze the effects of AKP on serum biochemical parameters, epiphyseal morphology and the transcription of the key genes related to endochondral ossification. Results: AKP could significantly increase the concentration of transforming growth factor-β (TGF-β), vascular endothelial growth factor (VEGF) and collagen type I (Col1α) in serum (P < 0.05), and promote the formation of fibrous callus, the formation and transformation of cartilage callus and the formation and reconstruction of sclerotic callus in a dose-dependent manner. AKP also significantly up-regulated the mRNA transcription levels of early chondrocyte differentiation factor (SOX9 and Col10α), middle and late angiogenic genes (VEGF and Ang1), cartilage matrix degradation factor (MMP13) and bone formation-related genes (Col1α, OCN and TGF-β). Conclusion: AKP can promote fracture healing by accelerating the process of endochondral ossification.

The aim of this research was to investigate the repairing effects of different doses of resistant starch from purple speckled kidney beans on liver and intestinal barrier injury in hyperlipidemia rats. The rat model was established by feeding the animals a hyperlipidemic feed. After that, different doses of kidney bean resistant starch were administered to the rats by gavage for 6 weeks. During this period, body mass, abdominal fat mass, liver index, blood lipid content, liver function, and serum antioxidant indices, diamine oxidase (DAO) and D-lactic acid (D-LA) concentration were measured. The pathological sections of liver and small intestinal mucosa tissues were observed as well. The results showed that there were significant differences in all parameters between the model and the blank groups (P < 0.01). Compared with the model group, body mass, liver index and abdominal fat mass of rats in the low-, middle- and high-dose resistant starch groups and the simvastatin group were significantly lower (P < 0.05, P < 0.01), blood lipid contents and liver antioxidant enzyme activities were also significantly reduced (P < 0.05, P < 0.01), the activities of serum superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were increased, and the concentration of malondialdehyde (MDA) was decreased to different extents. The levels of serum diamine oxidase and D-LA in all treatment groups were significantly decreased (P < 0.01). The results of hematoxylin-eosin (HE) staining showed that the morphology of liver and small intestine cells of rats in the resistant starch groups were clear and intact, and the inflammatory infiltration was reduced. Conclusion: Resistant starch from purple speckled kidney beans could improve liver and intestinal barrier damage caused by hyperlipidemia to some extent.

The aim of the research was to clarify the difference in the antioxidant activity of peptides derived from the in vivo digestion and in vitro processing of proteins, and further to verify the necessity of the in vitro processing of proteins for preparing antioxidant peptides. The antioxidant activity of egg white peptides derived from simulated gastrointestinal digestion and alkaline protease treatment were compared by chemical methods in vitro. Potent bioactive peptides with a molecular mass less than 1 kDa were isolated and sequenced from the alkaline protease hydrolysate and their protective effect on oxidative damage induced by H2O2 in human hepatoma cells (HepG2) was evaluated. The results showed that the antioxidant activity of the alkaline protease hydrolysate was significantly higher than that of the simulated gastrointestinal digestive products and untreated egg white protein. The antioxidant activity of both the enzymatic hydrolysate and the digestive products was negatively related to their molecular masses and significantly dose-dependent. The peptides with a molecular mass less than 1 kDa from the alkaline protease hydrolysate could effectively inhibit the production of reactive oxygen species induced by H2O2 in HepG2 cells, thereby preventing oxidative stress injury and apoptosis in cells. Three tetra-peptides, FYCP, YCPI and YLPR, were identified by ultra performance liquid chromatography/tandem mass spectrometry, all of which had good antioxidant activity. To a certain extent, this study provides an experimental basis for egg deep processing.

Sea cucumber fucoidan (SC-FUC) is one of the important bioactive components in the body wall of sea cucumber. Previous studies have shown that the biological activity of polysaccharides is closely related to their advanced structure. However, there are few reports on the association between the advanced structure of SC-FUC and its inhibitory activity against adipocyte differentiation. This work studied the effect of fucoidan from Holothuria mexicana (Hm-FUC) with different advanced structures on adipocyte differentiation, aiming to provide a theoretical basis for efficient utilization and development of SC-FUC. 3T3-L1 preadipocytes were differentiated into adipocytes by using the traditional cocktail method. The regulatory effect and molecular mechanism of Hm-FUC with different advanced structures on the differentiation of 3T3-L1 preadipocytes were studied by methyl thiazolyl tetrazolium assay, Oil Red O staining and reverse transcription real-time polymerase chain reaction. The results showed that all four Hm-FUCs tested significantly inhibited the proliferation and differentiation of 3T3-L1 preadipocytes, reduced the number of mature adipocytes, and decreased intracellular triglyceride levels. Moreover, they significantly downregulated the mRNA expression of crucial transcription factors regulating adipocyte differentiation such as SREBP1c, PPARγ, and C/EBPα (P < 0.05), upregulated the mRNA expression of key genes in the Wnt/β-catenin signaling pathway such as LRP5, LRP6, Frz, β-catenin, cmyc and Cyclin D1, and downregulated the mRNA expression of the negative regulatory factor GSK3β (P < 0.05), with Hm3 (210 kDa, with random coil short-chain configuration) showing the most significant effect. However, these Hm-FUCs showed no significant impact on the mRNA expression of Wnt10b. It is suggested that Hm-FUC could inhibit adipogenesis via activating the Wnt/β-catenin signaling pathway to downregulate the mRNA expression of the key transcription factors involved in adipocyte differentiation. Notably, the polysaccharide with molecular mass of 210 kDa and random coil short-chain configuration had the strongest inhibitory activity against adipocyte differentiation.

Objective: To study the hypoglycemic and lipid-lowering effects of Dendrobium officinale polysaccharide (DOP) in type 2 diabetic mice in order to provide a pharmacological basis for full utilization of Dendrobium officinale. Methods: Mice were injected intraperitoneally (100 mg/kg mb) with tetraoxopyrimidine to construct a mouse model of type 2 diabetes mellitus (T2DM). The following six groups of mice were set up: high-dose (450 mg/kg mb), medium-dose (300 mg/kg mb), low-dose (150 mg/kg mb) DOP, normal control, positive control (metformin hydrochloride, 250 mg/kg mb), and model groups. All animals were gavaged for 4 consecutive weeks. Blood biochemistry (triglycerides and total cholesterol content), renal function indexes (serum creatinine and urea nitrogen content) and antioxidant capacity were tested on the test mice. The results showed that: 1) Compared with the model group, DOP had a significant hypoglycemic effect in T2DM mice, especially at the high dose (P < 0.01), and it could significantly increase glucose tolerance (P < 0.05), high-dose DOP being as effective as metformin hydrochloride. 2) Compared with the model group, DOP could significantly reduce the contents of total cholesterol, low-density liptein cholesterol, and triglyceride and increase (high-density liptein cholesterol) content (P < 0.05), indicating that DOP can improve lipid metabolism disorders in diabetic mice. 3) Compared with the model group, DOP could significantly reduce serum urea nitrogen and creatinine levels (P < 0.05), indicating that DOP can improve kidney damage in diabetic mice. 4) Compared with the model group, DOP could significantly increase insulin level and reduce insulin resistance (IR). 5) Compared with the model group, DOP could significantly increase total antioxidant capacity (T-AOC), and the activity of superoxide dismutase (SOD) and catalase (CAT) (P < 0.05). Conclusion: DOP can significantly improve the antioxidant capacity in the liver and pancreas in diabetic mice and repair oxidative damage in the liver and pancreas, thereby increasing insulin level and alleviating insulin resistance, and finally exerting a hypoglycemic effect. DOP also has the function of improving lipid metabolism disorders and kidney injury in diabetic mice.

Objective: To explore the effect of chickpea peptide on the immune function in immunocompromised mice. Methods: Sixty male ICR mice were randomly divided into control, cyclophosphamide model and low-, medium- and high-dose chickpea peptide groups with 12 mice in each group. In the first three days of the experiment, the mice in all groups except the control group were intraperitoneally injected with cyclophosphamide at a daily dose of 80 mg/kg mb to establish an immunocompromised mouse model. Subsequently, the mice in the low-, medium- and high-dose groups were administered with chickpea peptide at doses of 0.4, 0.8 and 1.6 g/kg mb and those in the control and cyclophosphamide model groups with casein at 1.6 g/kg mb. After continuous gavage for 15 consecutive days, body mass, the mass and morphology of spleen and thymus, white blood cell count, immunoglobulin contents, peripheral blood T lymphocyte subsets, cytokine levels, bone marrow nucleated cell count and deoxyribonucleic acid (DNA) content were measured. Results: After modeling, the morphological structure of the spleen and thymus tissues in mice was disordered; white blood cell count, CD3+, CD4+ and CD8+ lymphocyte percentages, immunoglobulin contents, and the number of nucleated cells and DNA content in bone marrow were significantly reduced (P < 0.05); cytokine levels were significantly increased (P < 0.05). Compared with the model group, the above indicators in the chickpea peptide intervention groups were improved in different degrees, with the most significant effect being observed at the middle and high doses (P < 0.05). Conclusion: Chickpea peptide can enhance the immune function of immunocompromised mice induced by cyclophosphamide.

Flavonoids (FLS) are important bioactive components in Citrus paradisi cv. Changshanhuyou, which have a potential anti-obesity effect. To investigate their regulatory effect on the gut microbiota of obese mice, FLS from Citrus paradisi cv. Changshanhuyou were intragastrically administered to a high fat diet-induced obese mouse model for 8 weeks. During this period, feces were collected and all animals were killed to collect serum and liver tissues at the end. High-throughput sequencing technology was used to analyze the effects of FLS on the diversity and composition of the intestinal flora in mice. The results showed that FLS could significantly suppress body mass gain in obese mice (P < 0.05), decrease the contents of serum total cholesterol, triglyceride and low-density lipoprotein cholesterol (P < 0.05), increase serum high-density lipoprotein cholesterol content (P < 0.05), and attenuate hepatic lipid deposition. Further analysis showed that FLS significantly increased the abundance and diversity of intestinal microflora (P < 0.05). Although there was an inter-individual variation, the relative abundance of Bacteroidetes and Firmicutes at the phylum level increased and decreased, respectively, thereby leading to decreased ratio of F/B. At the genus level, FLS intervention increased the relative abundance of beneficial bacteria such as Bifidobacterium, Akkermansia, and Blautia that can produce short-chain fatty acids. Therefore, flavonoids from Citrus paradisi cv. Changshanhuyou can positively regulate the gut microbiota of high fat diet-induced obese mice so that they can be used as a functional food component to prevent intestinal microecological imbalance and reduce body fat by regulating the composition of intestinal microflora.

The objective of this study was to evaluate the preventive effect of betulinic acid (BA) on cyclophosphamide (CYP)-induced liver injury in mice. Fifty male healthy Kunming mice were randomly divided into 5 groups including control, CYP, and low-, medium- and high-dose BA groups. The mice from the control and CYP groups were administered orally with 1% starch solution, and those from the other groups with BA at doses of 0.25, 0.50 and 1.00 mg/kg mb for 14 days. Afterwards liver injury was induced by intraperitoneal injection of CYP at a dose of 50 mg/kg mb for 2 days for all groups except the control group, which was injected with physiological saline solution. The activities of aspartate transaminase (AST) and alanine aminotransferase (ALT) in the serum, the levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), glutathione (GSH) and malondialdehyde (MDA) in the liver, and the mRNA expression of pro-inflammatory cytokines interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and (IL-1β) and anti-inflammatory cytokine (IL-10) in liver were determined. The results showed as follows: 1) Pretreatment with BA increased the body mass of mice significantly at a dose of 0.50 mg/kg mb (P < 0.05), reduced the liver index significantly at 0.50 and 1.00 mg/kg mb (P < 0.05) when compared with the CYP group. 2) BA pretreatment decreased the activity of AST in a dose-dependent manner, and the effect showed a significant difference (P < 0.05) at 0.50 and 1.00 mg/kg mb. 3) Pretreatment with BA decreased hepatic vacuole degeneration caused by CYP. 4) BA reduced the activity of hepatic SOD (P < 0.05) significantly at 0.25 mg/kg mb, but had no effects on the levels of GSH-Px, CAT, GSH and MDA (P > 0.05) in the liver. 5) BA pretreatment at 0.25 and 1.00 mg/kg mb attenuated the CYP-induced increase in the mRNA expression of IL-1β (P < 0.05, P < 0.01), and significantly increased the mRNA expression of IL-6 and IL-10 (P < 0.01). At the same time, BA decreased the mRNA expression of TNF-α in the liver at 0.50 and 1.00 mg/kg mb (P < 0.01), but increased it at 0.25 mg/kg mb. Therefore, BA has a preventive effect against CYP-induced hepatic damage in mice via inhibiting the activity of antioxidant enzymes in the serum, decreasing lipid peroxidation in the liver, inhibiting the secretion of pro-inflammatory cytokines, and promoting the secretion of anti-inflammatory cytokines.

Purpose: To investigate the protective effect of honey polyphenol extract (HPE) on acute alcoholic hepatic injury in rats. Methods: Rats were randomly divided into blank control, model control, drug control (100 mg/(kg mb·d)), low- and high-dose HPE groups (100 and 200 mg/(kg mb·d)). After intragastric administration for 30 consecutive days, all rats except those in the blank control group were administered with Chinese Baiju containing 56% (V/V) alcohol at a dose of 15 mL/kg mb by gavage to establish an acute liver injury model. Twelve hours later, serum transaminase activity and antioxidant and anti-inflammatory indexes in liver were measured. The relative mRNA expression levels of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 kinase (p38) were determined by real-time quantitative polymerase chain reaction (qPCR). Hematoxylin-eosin (HE) staining was performed to observe the pathological changes of liver tissues. Results: Compared with the model group, the levels of alanine aminotransferase (ALT), aspartate aminotransaminase (AST), malondialdehyde (MDA) and tumor necrosis factor alpha (TNF-α) were decreased in the HPE treatment groups, and the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) and the level of reduced glutathione (GSH) were increased. Moreover, HPE downregulated the relative mRNA expression of ERK, JNK and p38, and improved the pathological changes of liver tissues. Conclusion: HPE has a protective effect on acute alcoholic liver injury in rats, and the underlying mechanism may be related to its antioxidant and anti-inflammatory activities.

Melatonin is a signal molecule similar to plant hormones and plays an important role in the physiological regulation of organisms. In the present study, fresh-cut mango fruit were sprayed with 0.5 mmol/L melatonin, sensory quality and nutritional quality were measured to investigate the effect of this treatment on the storage quality of fresh-cut mango, in order to provide a theoretical reference for its market application in freshi-cut mango. The results showed that melatonin treatment effectively slowed the decline in fruit color, firmness, soluble solids content and total titratable acidity content during storage. Melatonin treatment inhibited the reduction in the contents of β-carotene, ascorbic acid, total phenolics and flavonoids. Furthermore, this treatment significantly suppressed the rising in polyphenol oxidase (PPO) and peroxidase (POD) activity, thereby delaying enzymatic browning on mango pulp. In addition, melatonin treatment reduced the generation of reactive oxygen species (O2- · and ·OH) in fresh-cut mango while increasing 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and reducing power. In summary, melatonin spray treatment can significantly inhibit the quality deterioration of fresh-cut mango, consequently contributing to extending the shelf life.

The cryoprotective effects of inulin on myofibrillar protein from silver carp surimi were evaluated for use as an alternative to sugars that are used in commercial cryoprotectants. The cryoprotective effects of inulin and its mixtures with other cryoprotectants (1.5% inulin, 1.5% inulin + 4% sorbitol, 1.5% inulin + 2.5% sucrose + 4% sorbitol, 1.5% inulin + 0.3% sodium tripolyphosphate) on myofibrillar protein as well as the influence on the physical properties of surimi gels were compared with those of a commercial cryoprotectant (4% sucrose + 4% sorbitol) over 35 days of storage at ?18 ℃. Inulin and its mixtures with other cryoprotectants had a cryoprotective effect on surimi during frozen storage, as noted by suppressed decrease in Ca2+-ATPase activity, total and active sulfhydryl groups and salt-extractable protein, and alleviated increase in the surface hydrophobicity of myofibrillar protein. Moreover, surimi treated with 1.5% inulin + 0.3% sodium tripolyphosphate exhibited the best physicochemical properties in contrast to surimi samples treated with any other cryoprotectant.

In order to investigate the changes in the microstructure and quality of scallop (Patinopecten yessoensis) striated adductor muscle during chilling storage, live scallops with good vitality were shucked and then the striated adductor muscle was taken and stored at 4 ℃ for 5 days. The pattern of changes in its microstructure, the contents of ATP and related compounds, salt-soluble protein content, and myofibrillar ATPase activity was analyzed. The results showed that the striated adductor muscle contracted obviously, and its texture became harder accompanied by high drip loss on day 5 of storage. The abundant mitochondria in the muscle become vacuolate. However, the microstructure of the muscle remained relatively intact and no myofibrillar protein degradation was detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). After storage for 5 days, the ATP content remained at 1.07 μmol/g, while the Ca2+-ATPase activity of myosin increased from 0.41 to 0.50 μmol/(mg·min). The solubility of striated muscle protein remained at only about 60% in 1.0 mol/L NaCl, and at 25% in 0.4 mol/L NaCl, increasing to 70% when ATP was added to the homogenate or ethylenebis(oxyethylenenitrilo)tetraacetic acid was added to chelate Ca2＋ before homogenization. These results indicate that the binding of actin to myosin can activate myosin ATPase activity in vitro and affect the salt solubility of striated adductor muscle proteins.

In order to explore the correlation between the moisture mobility and quality changes in tilapia fillets under low temperature storage, fish fillet samples (about 130 g each) were frozen to an internal temperature of ?4 (traditional superchilling), ?8, ?12 or ?18 ℃ and stored for up to 28 days under modified atmosphere packaging (V(CO2) : V(O2) : V(N2) = 6:1:3). During the storage period, juice loss rate, total number of colonies, pH, total volatile basic nitrogen (TVB-N) content, color difference ΔE and water migration were measured and the correlation between water migration and other parameters was evaluated. The results showed that on the 7th day of storage, the highest juice loss rate was observe in the ?4 ℃ group. TVB-N content, total number of colonies, and ΔE value showed an upward trend during storage at all temperatures, and quality deterioration proceeded faster in the -4 ℃ group compared with the other temperature groups. pH slowly declined during storage ?18 ℃, while it showed an initial decrease followed by an increase at the other temperatures. Low-field nuclear magnetic resonance showed that the content of bound water content (A21) did not change significantly, the content of immobilized water content (A22) gradually decreased, and the content of free water content (A23) gradually increased with storage time. The most significant changes were observed at ?4 ℃, whereas the degree of water mobility at ?8 and ?12 ℃ was close to that at ?18 ℃. In general, A21, A22 and A23 were significantly correlated with ΔE and juice loss rate (P < 0.05) and also correlated with TVB-N content and pH. To sum up, the new superchilling technology at ?12 ℃ can be seen as a substitute for freezing to preserve fish quality.

In this study, the effect of sterilization methods on the microbial characteristics of rice cake was analyzed by investigating the trend of change in the total number of colonies during storage. The 16S rDNA V3-V4 region was sequenced by Illumina Miseq high-throughput sequencing technology. The effects of sterilization methods on the microbial community richness and diversity as well as the instrumental and sensory quality characteristics of rice cake were evaluated. The results showed that the total number of colonies in unsterilized and sterilized rice cake increased with storage time. The shelf lives of the untreated control, water-bath treatment and ethanol spraying groups were 3, 15 and 12 days, respectively. Alpha diversity analysis showed that sterilization had a great impact on the microbial richness and diversity of rice cake. In water bath treated rice cake, the dominant bacteria were Acinetobacter (40.49%), Pantoea (32.61%), and Salmonella (12.33%), while in the ethanol treated sample, the relative abundance of Pantoea and Salmonella was lower, and Acinetobacter (81.46%) and Microbacterium (10.74%) became the dominant bacteria. The Young’s modulus, firmness, toughness and masticatory power of rice cake gradually increased with storage time, whereas the elasticity, viscosity and sensory score showed a downward trend. More significant changes in these parameters were observed in the ethanol spraying group relative to the water bath treatment group. Collectively, it was concluded that water bath treatment is more suitable for maintaining the quality of rice cake during storage.

In order to evaluate the effects of dominant mold stains on rice quality, indica rice grown in Hunan, China was inoculated with different molds isolated from a rice granary and stored at 30 ℃ and 85% relative humidity. The number of molds, chromaticity, fatty acid value, soluble protein content, malondialdehyde (MDA) content, amylase activity, polyphenol oxidase activity and catalase activity were determined at different storage times. The results showed that Aspergillus flavus and Aspergillus niger from rice samples were isolated, both of which exhibited the biggest colony diameter of all isolates, and had a relatively larger effect on the deterioration of rice quality. The colony counts of the two fungal strains were increased by 2.029 and 1.960 (lg (CFU/g)) after the inoculated samples were stored for 10 days, which almost completely covered the surface of rice. The highest browning degree was found in rice inoculated with Aspergillus flavus at the end of the 10-day storage period. At this time, the fatty acid value and MDA content were the highest in rice inoculated with Aspergillus niger (148.93 mg/100 g and 108.82 nmol/g, respectively), followed by that inoculated with Aspergillus flavus (118.48 mg/100 g and 96.47 nmol/g, respectively). Aspergillus flavus had the greatest impact on the activity of polyphenol oxidase. The activity of polyphenol oxidase in rice inoculated with Aspergillus flavus was only 2.444 U/mg on the 10th day. Aspergillus flavus and Aspergillus niger both had the greatest impact on the activity of catalase in rice, and the activity of catalase in the inoculated samples was 0.014 and 0.181 U/mg on the 10th day, respectively. This indicates that more attention should be paid to the prevention and control of Aspergillus flavus and Aspergillus niger in future studies on grain storage safety.

To investigate the effects of storage temperature on the quality of rice, the pattern of changes in quality indexes of ‘Liaoxing’ rice under different storage temperatures (15, 20–25, 37 ℃) was studied, and a kinetic model that fitted the experimental results to describe each quality index was determined, aiming at providing reference for predicting quality changes during rice storage. The results showed that higher storage temperature had a more significant effect on the surface morphology of rice endosperm. Rice showed inferior quality after being stored at high temperature (37 ℃) for 300 days. The physicochemical properties, appearance, texture, cooking and pasting properties of rice changed greatly during storage, and the higher the storage temperature, the greater the change. According to fatty acid values and catalase activity, the storage period of rice stored at 15 ℃, room temperature (around 20–25 ℃) and 37 ℃ was less than 240, 180, and 120 days respectively, and the quality of rice deteriorated beyond this period. The results of gas chromatography-ion mobility spectrometry (GC-IMS) indicated that the concentrations of 1-butanol, dimethyl disulfide, cyclohexanone increased with the increase in storage temperature, thus indicating that these substances may be crucial to produce off-odor during the storage of rice. Principal component analysis showed that rice at different storage temperatures had significant differences in odor components. Zero-order kinetic models could better describe the changes of fat content, swelling rate, pH of rice soup, solid content of rice soup, lipase activity, fatty acid value and catalase activity, while first-order kinetic models could better describe the changes of thiol content and water absorption during rice storage.

The pattern of changes in water mobility, protein structure and texture characteristics in Takifugu obscurus meat under low temperature storage (10, 4 and ?3 ℃) was explored, and the correlations of transverse relaxation times with texture parameters, protein properties and structure were evaluated to explore a rapid method to monitor quality changes of Takifugu obscurus under low temperature storage. The results showed that prolongation of the storage time led to increased T2b (bound water) and T22 (free water) and alternate increase and decrease in T21 (immobilized water). Elasticity and hardness showed a downward trend for all temperature groups, with the ?3 ℃ group exhibiting the highest cooking loss rate, centrifugal loss rate and drip loss rate. Scanning electron microscopic (SEM) analysis indicated that superchilling (?3 ℃) could destroy fish muscle fibers, thus affecting the texture and water-holding capacity. During low temperature storage, the contents of disulfide bonds, carbonyl groups and total free amino acid (FAA) increased, whereas the content of sulfhydryl groups and Ca2+-ATPase activity decreased. The results of Fourier transform infrared spectroscopy showed that the relative contents of α-helix and β-sheet decreased and increased in a fluctuant fashion, respectively. Correlation analysis showed that T2b and T22 in all temperature groups were significantly correlated with centrifugal loss rate, drip loss rate, disulfide bond content, β-sheet relative content relative, total FAA content, sulfhydryl content, Ca2+-ATPase activity, endogenous fluorescence intensity and elasticity (P < 0.01 or 0.05), demonstrating that changes in transverse relaxation times are useful to quickly predict quality changes of Takifugu obscurus during low temperature storage.

Objective: To study the effect of postharvest nitric oxide (NO) treatment on wound healing in potato tubers, and to partially explore the underlying mechanism. Methods: Potato tubers of the cultivar ‘Longshu 7’ were artificially wounded, dipped with sodium nitroprusside (SNP) as an exogenous donor of NO at 0.5 mmol/L for 10 minutes, and then allowed to heal at ambient temperature in darkness. The mass loss rate of wounded tubers and the disease index of those inoculated with Fusarium sulphureum were measured during the healing period, and the accumulation of suberin and lignin was observed in the wounds. Phenylpropanoid metabolism and peroxidase activity as well as H2O2 content in the wounds were also analyzed. Results: The mass loss rate of wounded tubers and the disease index of inoculated tubers were significantly reduced by NO treatment during healing period, which were 43.5% and 27% lower than that of the control on day 7 of healing. The treatment accelerated the accumulation of polyphenol suberin, polyaliphatic suberin and lignin, increasing the thickness of the polyphenol suberin, polyaliphatic suberin and lignin layers by 25.2%, 27.3% and 23.6% relative to the control on day 7, respectively. Also, the treatment increased phenylalanine ammonia-lyase activity, and the contents of total phenols, flavonoids and lignin in the wounds by 75.3%, 31%, 39.6% and 32.8% compared with those of the control on day 14, respectively. In addition, NO increased significantly peroxidase activity and hydrogen peroxide content (P < 0.05). Conclusion: NO treatment can activate phenylpropane metabolism, improve peroxidase activity and H2O2 content, and accelerate suberin and lignin accumulation in the wounds, thereby promoting wound healing in potato tubers.

Meat and meat products are subject to varying degrees of oxidative stress during processing and storage due to the specificity of muscle tissue. Protein is a major component of muscle tissue, and oxidative protein damage can lead to oxidative modification of amino acid side chain groups, cross-linking between peptide chains, peptide backbone cleavage and conformational changes, thus altering the functional properties of proteins and ultimately affecting the quality characteristics of the products. Previous studies are mostly focused on the negative effects of protein oxidation on the quality characteristics of meat products. However, recent studies have shown that protein oxidation plays a positive role in the quality characteristics of meat and meat products to a certain extent. Hence, this paper is devoted to review the state-of-the-art literature regarding the positive and negative effects of protein oxidation on meat and meat products as well as the underlying mechanisms.

Meat color is an important indicator to determine consumers’ desire to purchase. Among the many factors can affect meat color, lipid oxidation is an important one. Lipid oxidation affects meat color mainly through primary and secondary metabolites produced from this process and its impact on mitochondrial activity. The effect of primary metabolites from lipid oxidation on meat color has been very clear. However, the effect of secondary metabolites from lipid oxidation on meat color and the pathways by which lipid oxidation affects meat color indirectly through its impact on mitochondria activity have not been fully understood. In this article, we review recent knowledge on the mechanism of lipid oxidation and the pathways by which it affects meat color, and we summarize the main factors influencing the progress of lipid oxidation and the available methods for controlling this process, in order to provide a theoretical rationale for meat color maintenance by controlling lipid oxidation control in the future.

Fungal infection and mycotoxin contamination in agricultural products can affect human health and consumption safety. Early detection of fungal and mycotoxin contamination is an essential control measure for extending storage period and ensuring food safety. Conventional methods for the identification of fungal infection and mycotoxin detection are time-consuming, expensive, difficult to automate or unable to meet the requirements for on-site rapid detection. In recent years, increasing attention has been paid to the development of simple, rapid and non-destructive techniques for fungal identification and mycotoxin detection in agricultural products. This paper reviews the application of imaging, spectroscopy and electronic nose in the identification of mycotoxin-producing fungi and mycotoxin detection. Moreover, challenges and future trends of these techniques are also presented.

As highly dynamic organelles, mitochondria are in continuous dynamic change. Mitochondrial biogenesis is crucial to maintain mitochondrial network homeostasis, and is also a new medium to regulate the transformation of muscle fibers. Lactic acid bacteria can promote mitochondrial biogenesis by inducing the activation of intracellular kinase in skeletal muscle cells, enhancing signal induction of reactive oxygen species and peroxisome proliferator-activated receptor gamma co-activator-1α transcription, thereby affecting the transformation of muscle fiber types. The type of skeletal muscle fibers is closely related to muscle quality. Therefore, the regulation of mitochondrial biogenesis by lactic acid bacteria to affect the transformation of muscle fiber types is considered an important way to improve meat quality in the future. This paper reviews the molecular mechanism by which lactic acid bacteria can regulate mitochondrial biogenesis in skeletal muscle, and the relationship of mitochondrial biogenesis with muscle fiber transformation and meat quality, which will provide a theoretical rationale for regulating mitochondrial biogenesis and promoting muscle fiber type transformation in order to improve meat quality by supplementing lactic acid bacteria in the future.

Oxidation is an important cause for quality deterioration of meat and meat products. The use of antioxidants can effectively inhibit the oxidation of meat products. However, as increasing efforts have been made to understand their toxicology, the safety of synthetic antioxidants has been questioned. Natural antioxidants are widely distributed in nature, and they show no signs of low toxicity when consumed over a long period of time, which have the advantages of safety and high efficiency. The application of natural antioxidants as substitutes for synthetic antioxidants has become a hot topic in meat research today. In this paper, the types, sources, bioactive ingredients, functions and mechanism of action of natural antioxidants as well as the methods for addition of natural antioxidants to meat products are summarized. Meanwhile, the latest progress in the application of natural antioxidants in meat and meat products is reviewed. Moreover, the current research status and future directions are discussed. This review is expected to provide a theoretical basic support for the application of natural antioxidants in meat products.

As important indicators to evaluate intestinal development, normal proliferation and differentiation of intestinal cells and the integrity of the mucosal barrier largely determine energy homeostasis and overall growth performance of humans and animals, thereby being considered as fundamental determinants of physiological homeostasis in humans and animals. Good microbe-host communication and their symbiotic relationship have positive effects on intestinal development and homeostasis. In recent years, a large number of studies worldwide have shown that intestinal microorganisms are involved in the regulation of intestinal proliferation and differentiation, including lactic acid bacteria which have been reported for probiotic properties. In order to provide insights into the role of probiotics in regulating intestinal development, intestinal composition and developmental mechanism are described in detail, and the functions of probiotics in promoting the proliferation and differentiation of intestinal epithelial cells and intestinal stem cells, enhancing intestinal mucosal barrier function, and maintaining good intestinal morphology as well as the underlying mechanisms are reviewed from three aspects, including probiotic cell components (such as pilin and cell wall components), metabolites (butyric acid and butyrate), and intestinal flora diversity and colonization status.

Micro (nano) plastics are emerging environmental pollutants that have received much attention in recent years. Micro (nano) plastics and harmful substances attached to them can accumulate in living organisms and be enriched in the human body through the food chain, posing a potential threat to food safety and human health. At present, micro (nano) plastics have been detected in a variety of foods. In this paper, the latest progress made over the past five years in research on the status of micro (nano) plastics pollution in foods and the analytical methods used in this area are reviewed, and the potential harms of micro (nano) plastics to human health are discussed based on their toxicity of micro (nano) plastics to human cells and their transport and absorption in mammals. An outlook of future research directions is also presented. This review is expected to provide support for in-depth studies of micro (nano) plastics contamination in foods in China.

Edible fungi are rich in proteins, polysaccharides, vitamins and other bioactive ingredients. However, the types and contents of functional ingredients and thus the functions and mechanism of action of edible fungi vary due to varying species, geographical origins, climate conditions, cultivation methods, and production and processing factors. Therefore, it is particularly important to study the production, processing, effective utilization and functional mechanisms of edible fungi. Edible fungi have a long history of use for culinary and medicinal purposes. As an excellent food resource with good nutritional and healthcare functions, edible fungi have broad research prospects and can be potentially applied in health foods and medicine. This paper reviews the authoritative basis for and the current status of the application of edible fungi in health foods in China and the health-promoting functions of edible fungi incorporated in health foods. From other counties’ recent achievements in edible fungi research, some enlightenments are drawn for the research and development of edible fungi-based health foods in China. This review is expected to provide a reference for in-depth exploitation and development of edible fungi as raw materials of health foods.

An emulsifier is a substance that mixes (disperses) two immiscible liquids (oil and water) to form a homogeneous dispersion (emulsion). Emulsifiers are usually amphiphilic molecules which can form a monomolecular layer at the interface of two immiscible liquids and reduce their interfacial tension. The addition of emulsifiers can promote the formation of the emulsion and improve its stability and functionality. Emulsifiers can be divided into natural emulsifiers and synthetic emulsifiers according to their sources. Considering the safety of synthetic emulsifiers and the limited stability of a single natural emulsifier, two or more emulsifiers should be blended to improve the functionality of each emulsifier alone. This article reviews the mechanism of single and mixed emulsifiers for stabilizing emulsions. Mixed emulsifiers work by changing the force between oil droplets and the competitive adsorption between the individual emulsifiers. Furthermore, the binding mode and mechanism of protein-polysaccharide composite emulsifiers. This review will lay a theoretical foundation for the application of single and mixed emulsifiers in emulsions.

The occurrence of cardiovascular disease (CVD) is mainly affected by the environment and heredity, and the major causes include blood abnormalities such as hyperglycemia and hyperlipidemia, as well as diabetes and atherosclerosis (AS). CVD has become a heavy health burden on individuals. The current status of research on the preventive effect of tea functional ingredients such as polyphenols, polymerized catechins and polysaccharides alone and in combination with natural products on CVD is summarized. The major underlying mechanisms are reviewed such as by reducing blood glucose and lipids, regulating intestinal function, preventing AS or exerting other related protective effects. Directions for future utilization and research of tea functional components are also proposed. This review will provide a theoretical reference for the prevention of sub-health by drinking tea and for the development of functional tea products.

Camel milk can provide essential nutrients for the human body and has a high nutritional value. In addition, it also has various functional characteristics and health effects, making it a high quality milk source. Camel milk has natural bioactive factors and medicinal components, and its protective protein content is higher than that of other ruminant milks. There are many amino acid sequences of bioactive peptides in the primary structure of camel milk protein that can be released only by hydrolysis to exert their functions. At present, hydrolyzed camel milk protein is known to contain bioactive peptides with potential functions including antioxidant, antihypertensive, antibacterial and hypoglycemic activity, which can effectively improve human health so that they have attracted more and more attention. In this paper, the potential biological characteristics of peptides produced from protease hydrolysis or microbial fermentation of camel milk/camel milk protein are reviewed, as well as the effectiveness in the prevention and treatment of chronic diseases, which is expected to provide a strong theoretical basis for the development and utilization of bioactive peptides derived from camel milk in the future.

Resistant starch (RS) is a kind of emerging food ingredient that contributes to good mouth feeling and there are wide sources of RS. RS can resist digestion by α-amylase due to physical entrapment and structural alterations and cannot be digested or absorbed in the stomach and small intestine but eventually be fermented and decomposed by the large intestine microflora. RS can increase the volume of intestinal contents and speed up intestinal transport after entering the large intestine, and it can also change the structure of intestinal flora. At the metabolic and molecular level, RS exerts probiotic properties to prevent and alleviate many diseases through decomposition products, such as butyrate and other short-chain fatty acids. In this paper, the latest studies on the preventive and alleviating effects of RS on colorectal cancer (CRC), diabetes mellitus and chronic kidney disease (CKD) are reviewed, and the major pathways of action of RS are elucidated at the metabolic and molecular levels. Besides, an outlook is given on future studies on the physiological functions of RS, which will hopefully extend its potential value in the future.

Since ancient times, traditional fermented foods are a part of people’s daily diet, and have strong regional characteristics. Food microorganisms are an important part of traditional fermented foods, and play a decisive role in the quality and safety of fermented foods. Exploring the composition, groups, succession pattern, mechanisms of action and functions of fermentation microorganisms in fermented foods can lay a theoretical foundation for modern industrial production of high-quality and stable fermented foods. In this article, the types of traditional fermented foods in different countries and regions, the groups of microorganisms in traditional fermented foods, the regulatory systems, the mechanisms of action and the relationship between the types of interactions and the development of starter cultures are reviewed. The application of meta-omics in fermented foods is also summarized.

Fruits and vegetables contain abundant phenolic substances, which possess multiple biological activities such as anti-cancer, antioxidant, antibacterial and antiviral functions. In recent years, the bioavailability of phenolic substances has attracted increasing concerns, including gastrointestinal digestion and intestinal microbial decomposition, and the effect of processing methods on the in vitro digestion and intestinal fermentation of phenolic compounds; however, a systematic conclusion is still lacking. This review focuses on the main digestion and absorption as well as processing factors affecting the bioavailability of phenolic compounds in fruits and vegetables, which is expected to provide a theoretical rationale for regulating the bioavailability of phenolic compounds in processed fruits and vegetables products.