In order to systematically investigate the relationship between changes in egg freshness and S-ovalbumin content and to clarify the effect of various egg quality parameters on the increase in S-ovalbumin content during storage, fresh eggs from Hyline Brown laying hens were tested for Haugh unit (HU), egg yolk index and pH and their correlation with S-ovalbumin content, and the gray correlation degree of egg quality parameters and S-ovalbumin content was analyzed. In addition, the prediction model of equivalent egg age was established with S-ovalbumin content as independent variable. The results showed that there was a strong negative correlation between HU and S-ovalbumin content (R = ?0.913, P < 0.01), and that S-ovalbumin content had a strong negative correlation with egg mas (R = ?0.367, P < 0.01) and a strong negative correlation with concentrated protein height (R = ?0.905, P < 0.01). A strong negative correlation existed between egg yolk index and S-ovalbumin content (R = ?0.900, P < 0.01), and the correlation between pH and S-ovalbumin content was positive (R = 0.648, P < 0.01). In addition, the comprehensive gray correlation degree between each quality factor and S-ovalbumin content was more than 0.6, and pH was the dominant factor affecting the change of S-ovalbumin content (gray correlation degree was 0.742). The decision coefficient (R2) of the established polynomial regression model for equivalent age prediction was 0.986 81 (P < 0.01).

In this work, the effect of electron beam irradiation at different doses (0, 1, 3, 5, 7 and 9 kGy) on gel properties of Collichthys lucidus surimi was addressed and the underlying mechanism was elucidated. For this purpose, waterholding capacity (WHC), whiteness, texture, chemical interactions, myofibrillar protein composition and rheological properties of surimi samples were determined. The results indicated that hydrophobic force and disulphide bond played a major role in stabilizing heat-induced surimi gels. The whiteness, WHC, texture of surimi gels were better at 5 kGy than at other irradiation doses. Irradiation at 5 kGy resulted in higher storage modulus (G’) and lower loss tangent (tan δ) compared to the control group. G’ slowly increased with temperature up to 31 ℃, then slightly decreased with increasing temperature to 43 ℃ and finally increased rapidly again at temperatures higher than 43 ℃. As a result, surimi gels were formed. Finally, it is concluded that 5 kGy is the most suitable irradiation dose to induce gel formation and improve surimi quality due to its significant effect on chemical interactions and rheological properties of surimi (P < 0.05).

The aim of this study was to investigate the effect of different feeding patterns on the expression of lipid metabolism genes in intramuscular, tail and perirenal adipose tissues from 12 month-old Sunit sheep by quantitative real-time polymerase chain reaction (PCR). The results showed that for all three adipose tissues, the expression of stearoyl-CoA desaturase gene (SCD) in stall-fed sheep was significantly higher than in grazing sheep (P < 0.05); the expression of Δ5-fatty acid desaturases (FADS1), Δ6-fatty acid desaturases (FADS2), elongase of very long chain fatty acid 5 (Elove5) and peroxisome proliferator-activated receptor (PPARγ) in grazing sheep were higher than in stall-fed sheep (P > 0.05). The expression of lipoprotein lipase (LPL) in tail and perirenal adipose tissues from grazing sheep were higher than that stall-fed sheep (P < 0.05). The expression of each lipid metabolism gene in different adipose tissues differed significantly. The gene expression of FADS1, FADS2, Elove5 and carnitine palmitoyltransferase I (CPT1) in intramuscular adipose tissue was significantly higher than in the two other adipose tissues (P < 0.05), whereas the expression of PPARγ in intramuscular adipose tissue was significantly lower (P < 0.05). In tail adipose tissues, the expression of SCD had a significantly positive correlation with the expression of acetyl-CoA carboxylase (ACC) (P < 0.01), which was beneficial to the deposition of monounsaturat ed fatty acids in adipose tissues.

In the present study, crude polysaccharides, flavonoids and alkaloids with potential antidiabetic activity were synchronously extracted from the leaves of Morus nigra L. and separated by column chromatography. The α-glycosidase inhibitory activity of the three active substances was investigated individually and in combination. Statistical analysis of the interactions among these substances was carried out using CompuSyn software. The results showed that all three active components from the leaves of Morus nigra L. had α-glucosidase inhibitory activity. Moreover, the alkaloids had better α-glucosidase inhibitory activity than acarbose, while the polysaccharides only at higher concentrations had an obvious inhibitory effect on α-glycosidase, which was directly proportional to concentration. At concentrations tested, the alkaloids showed antagonism against the flavonoids and polysaccharides when used in combination, whereas the flavonoids could synergize with the polysaccharides alone and its mixture with the alkaloids.

Walnut skin color is one of the most important quality parameters for walnut grading. In this paper, the effects of walnut skin color and its removal by blanching on the color, nutritional composition and stability of pressed walnut oil were studied. The results showed that oil color was not significantly affected by walnut skin color (P > 0.05) and was not affected at all by peeling treatment. In the case of nutritional composition, there were no significant differences in unsaturated fatty acids, total phenolics or tocopherols between dark-colored and light-colored walnut oils; although the peeling treatment had no obvious effect on unsaturated fatty acids, but it decreased total tocopherols by 20.19% and 16.33% in the darkcolored and light-colored oils, respectively. The content of total phenolics was quite low in dark-colored and light-colored oils obtained from unpeeled walnuts and most of the phenolics were remained in meals. With respect to stability, no significant difference was found between the two oils; after peeling, the oxidation induction periods of the dark-colored and light-colored oils decreased by 0.68 and 0.53 h, respectively, and the shelf lives of 60 ℃ decreased by 5.52 and 3.36 h, respectively. In addition, it was found that the oil yield during pressing was improved by the presence of walnut skin; after peeling, the oil yields from dark-colored and light-colored kernels decreased by 5.43% and 3.29%, respectively.

Yolk gelation occurs when stored at temperatures below ?6 ℃, which will affect yolk application in food processing. The gelation of yolk frozen for 180 d was characterized by rheological properties, and the physicochemical properties, water distribution and secondary structure were analyzed to further explore the cause of yolk gelation. Apparent viscosity, viscosity coefficient (K) value, elasticity modulus (G’) and viscous module (G’’) in yolk were significantly increased, while flow index (n) value and loss tangent (tan δ) were significantly decreased during frozen storage, suggesting that freezing led to serious gelation of yolk. Yolk gelation was caused by the increased average particle size and surface hydrophobicity, the decreased total sulfhydryl and the change in moisture distribution, and especially by the reduced freezable water content in yolk; meanwhile, the secondary structure transformation from a disordered to an ordered state of yolk proteins also promoted yolk protein aggregation and consequently induced yolk gelation. The cause of yolk gelation reported in this study provides a theoretical basis for further improving yolk gelation during freezing process.

In order to determine the suitable range of quality attributes of early indica rice for processing pressed fresh rice noodles and ensure the quality stability of rice noodles, the physicochemical and pasting characteristics 40 early indica rice varieties from two major producing areas of Hubei and Jiangxi province and the quality characteristics of rice noodles processed from these rice varieties were evaluated by descriptive analysis and correlation analysis. The results showed that the variation coefficients for the majority of 15 quality indexes of rice were greater than 10%, with the highest value of 75.9% being observed for chalkiness. Grain length, the percentage of chalky grains and peak time were significantly correlated with the sensory score of rice noodles, which had a highly significant correlation with amylose content, trough viscosity, final viscosity, setback and breakdown of rice starch, showing the largest correlation coefficient of 0.579 with setback. Compared with the physicochemical indexes of rice, the pasting characteristics of rice starch were more effective at reflecting the quality of rice noodles. Analysis of the quality indexes of early indica rice by factor analysis showed that the first four common factors explained 76.264% of the total variance and two of these, namely amylose content and setback, were significantly correlated with sensory score of rice noodles with correlation coefficients were 0.539 and ?0.332, respectively. Using stepwise regression, an equation was obtained as follows: Ysensory score of rice noodle = 51.876 + 0.494xamylose content + 0.008xsetback (R2 = 0.423). Amylose content and setback were selected as the sensitive indexes to reflect the quality of rice noodles and their threshold ranges in suitable varieties for processing pressed fresh rice noodles were found to be 22.24%– 26.86% and 1 526.5–2 036.7 cP, respectively based on clustering analysis.

In order to understand the correlation between physicochemical indexes and microbial communities of pit mud and further to screen out the physicochemical indexes that reflect the quality of pit mud, the microbial community structures in pit muds with different qualities were investigated by high-throughput sequencing, and correlation analysis was carried out between microbial community structure and physicochemical indexes. The results showed that the contents of water, total nitrogen and ammonium nitrogen showed an increasing trend with improved quality of pit mud, and the pH approached 7. Principal component analysis of physicochemical indicators showed that the contents of ammonium nitrogen, total nitrogen, available phosphorus, humic acid, pH and Fe had great influence on pit mud quality. Total nitrogen was positively correlated with Firmicutes, Synergistetes and Actinobacteria, but negatively correlated with Chlorflexi and Proteobacteria. Ammonium nitrogen content was positively correlated with Firmicutes, Synergistetes and Actinobacteria, but negatively correlated with Proteobacteria and Spirochaetes. There was a positive correlation between available phosphorus and Synergistetes or Actinobacteria. Humic acid and Proteobacteria were positively correlated. pH was positively correlated with Firmicutes and Proteobacteria, but negatively correlated Chlorflexi with Spirochaetes. All correlations were statistically significant (P < 0.05 or P＜0.01). Redundancy analysis showed that ammonium nitrogen, total nitrogen, available phosphorus and pH had the greatest influence on microbial communities, followed by water, humic acid, calcium and iron contents. To sum up, total nitrogen, ammonium nitrogen and pH were screened out as quality indicators of pit mud. The better the quality of pit mud, the higher the contents of total nitrogen and ammonium nitrogen and the closer the pH was to 7.

This study was designed to explore the inhibitory effect of polyphenols from Aronia melanocarpa berries on α-amylase activity and their antibacterial activity. The antimicrobial activity against Escherichia coli, Staphylococcus aureus, Aspergillus flavus, Aspergillus fumigatus, Rhizopus oryzae, Penicillium islandicum and Trichoderma koningii was investigated by the filter paper disc method, and the influence of temperature and pH on the inhibition of Staphylococcus aureus and Aspergillus fumigatus was examined. The inhibitory effect of Aronia melanocarpa polyphenols on α-amylase were studied by kinetic modelling. The results demonstrated that Aronia melanocarpa polyphenols inhibited all seven strains tested. Among them, the strongest inhibitory effect against Aspergillus fumigatus was observed with a minimal inhibition concentration (MIC) of 0.171 9 mg/mL. At pH 5.0, Aronia melanocarpa polyphenols had the strongest antibacterial activity against Staphylococcus aureus. But the antibacterial activity against Aspergillus fumigatus could be destroyed by changing the pH. Furthermore, Aronia melanocarpa polyphenols had an obvious inhibitory effect on α-amylase. Compared with the positive control of acarbose, Aronia melanocarpa polyphenols were more active against α-amylase within the concentration range of 0.10–0.70 mg/mL. The inhibition was non-competitive and reversible and the inhibition constant was 0.193 2 mg/mL. Aronia melanocarpa polyphenols enhanced the ultraviolet absorption intensity of α-amylase at 202 nm and led to a redshift in the absorption peak wavelength. Therefore, Aronia melanocarpa polyphenols can be used as a new α-amylase inhibitor and antimicrobial agent.

In this paper, acetic acid and nitric acid were used as the catalysts for selenium modification of rice embryo polysaccharides (REP), and the antioxidant properties of the native and modified polysaccharides (Se-REP1 and Se-REP2) were studied. The in vitro antioxidant activity was evaluated by using O2 -·, ·OH and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging capacity and reducing power assays. The antioxidant activity in vivo was evaluated by determining the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), malondialdehyde (MDA) and total antioxidant capacity (T-AOC) in mouse serum, liver, kidney and heart tissues. The results showed that all the native and modified polysaccharides at five concentrations had different O2 -·, ·OH and DPPH radical scavenging capacity, and their reducing power was increased with the increase of their concentration. Both Se-bound polysaccharides could improve the activity of SOD, GSH-Px and T-AOC in mice tissues and serum, and the effect was stronger than that of REP, but the activity of T-AOC in heart tissue was not significantly different between the modified and native polysaccharides. The contents of MDA in liver and kidney were much lower than that in the control group although the effect was not significant. On the other hand, the contents of MDA in serum and heart tissue showed an obvious significance, and administration of Se-bound REP prepared with acetic acid showed the highest antioxidant enzyme activity in mice.

Objective: To evaluate and compare the antioxidant and antimicrobial capacity of polysaccharides from Auricularia cornea var. Li, Auriculari auricula, Auricularia polytricha, was determined. Methods: The polysaccharides were obtained by water extraction followed by ethanol precipitation and the polysaccharide content was determined. The total antioxidant capacity and the scavenging activity against hydroxyl, superoxide anion, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals and nitrite of the three polysaccharides were measured by spectrophotometry. Besides, the minimum inhibitory concentration (MIC) method was employed to compare the antimicrobial activity of the polysaccharides against Escherichia coli, Staphylococcus aureus and Bacillus subtilis. Results: Under the same conditions, the extraction yields of crude polysaccharides from Auricularia cornea var. Li, Auricularia auricula and Auricularia polytricha were 13.87%, 11.26% and 7.91%, respectively, and the purities of the obtained polysaccharides were 49.22%, 41.50% and 37.97%, respectively. Among these, Auricularia polytricha polysaccharides had the highest total antioxidant capacity, while the antioxidant activities of the two other polysaccharides were lower and similar to each other. The hydroxyl radical scavenging capacity of Auricularia cornea var. Li polysaccharides was slightly stronger than that of Auricularia auricula, although both of them showed similar superoxide anion radical scavenging activity, which was stronger than that of Auricularia polytricha polysaccharides. Moreover, all three polysaccharides exhibited potent DPPH radical scavenging capacity with an inhibition percentage of 80% with Auricularia cornea var. Li polysaccharides being the most effective. Auriculari auricular polysaccharides had slightly higher nitrite scavenging capacity than the other polysaccharides. All these polysaccharides had an inhibitory effect on Escherichia coli, but Auricularia polytricha and Auricularia auricula showed weak inhibitory effect on Staphylococcus aureus or Bacillus subtilis. Only Auricularia cornea var. Li. polysaccharides presented a marked inhibitory effect on both Staphylococcus aureus and Bacillus subtilis. Conclusion: The polysaccharides from three Auricularia species have significant differences in antioxidant and antibacterial capacity.

The effects of seven cooking methods (steaming, boiling, microwaving, baking, air-frying without oil, airfrying with oil and frying) on micronutrients, umami nucleotides, texture, color and sensory quality of ‘Zihuabai’ potatoes (Solanum tuberosum L.) were investigated and the quality indexes of cooked potatoes were analyzed by principal component analysis (PCA). The results showed that the minimum loss of macronutrients after steaming and microwaving was observed compared to others cooking methods; microwaving significantly maximized the content of umami nucleotides. The texture properties were significantly influenced by air-frying without oil; cooked potatoes were much deeper in color after airfrying with oil and frying; the sensory score of boiled potatoes was the highest. The overall quality scores of seven cooked potatoes, as determined by PCA, followed the decreasing order of air-frying with oil > microwaving > frying > boiling > baking > steaming > air-frying without oil. In conclusion, steaming is a better choice for pre-cooking before potato deep processing; air-frying with oil can maintain better quality of cooked potatoes, while microwaving can meet consumer demands for low-fat foods.

In order to improve the utilization of soybean proteins, soybean glycinin (11S) and β-conglycinin (7S) were subjected to ultrasound pretreatment before hydrolysis in this study, and then the structural changes of ultrasound treated and untreated 7S and 11S hydrolysates were studied by fluorescence spectroscopy, Fourier transform infrared spectroscopy and ultraviolet-visible absorption spectroscopy. The results showed that the secondary and tertiary structures of 7S and 11S hydrolysates were partially unfolded. Compared with the control, both treated 7S and 11S hydrolysates showed an increase in α-helix and β-turn proportions, and a decrease in β-sheet and random coil proportions, which suggested that the hydrophobic groups inside molecules were exposed to the surface. Moreover, ultrasonication significantly increased the degree of hydrolysis of 7S and 11S hydrolysates (P < 0.05) than the untreated controls. The antioxidant activity of the treated 7S and 11S hydrolysates demonstrated a significant improvement in reduction capacity, hydroxyl free radical scavenging activity and iron chelating capacity as compared to their respective untreated counterparts. Therefore, ultrasound pre-treatment is an effective way to enhance the hydrolysis of 7S and 11S to prepare hydrolysates with high antioxidant activity. These results can provide theoretical support for the development of natural antioxidant substances from soybean protein.

Power ultrasound as an effective way to trigger the initial nucleation of solutions can transform the spontaneous and random process of ice crystal nucleation into a predictable and easy to control one. In this study, the nucleation of catalase solutions with different dissolved oxygen contents was controlled with contact ultrasound before freeze-drying in order to investigate the effect of air injection into the solution on the sublimation drying rate, the porosity and the enzyme activity recovery. The results showed that the sublimation drying time was reduced by 9.36%–41.63% with increasing dissolved oxygen from 4.10 to 13.44 mg/L and the enzyme activity recover was higher than 95% in the dissolved oxygen range of 4.10–10.24 mg/L. The application of controlling crystal nucleation by power ultrasonic with air injection in the vacuum freeze drying of foods and pharmaceuticals is of great significance to shorten the drying time, reduce energy consumption and improve the quality of freeze-dried products.

The inactivation kinetics of polygalacturonase (PG) after heat and ultrasonic treatments were investigated. PG activity was determined by colorimetry using 3,5-dinitrosalicylic acid. The results indicated that PG was not obviously inactivated by heat ( ≤ 45 ℃) or ultrasonic treatment alone (20 kHz; 0 ℃; 242, 605 or 968 W/cm2 power density), retaining more than 80% of its original activity. The activity of PG was almost constant after 15 min of heat or ultrasonic treatment. The inactivation curve was well fitted with a partial transformation model. PG was significantly inactivated by combined heat (25–45 ℃) and ultrasonic treatment and the inactivation curve was fitted with a first-order kinetic model. The activity of PG was decreased to 13.72% by ultrasonic treatment at 20 kHz, 35 ℃ and 605 W/cm2 power density for 16 min. However, neither heat treatment (35 ℃ for 5 min) followed by ultrasonic treatment (605 W/cm2 power density and 0 ℃ for 0–10 min) nor the reverse sequence (ultrasonic treatment for 5 min and subsequent heat treatment for 0–10 min) inactivated PG, indicating that ultrasonic and heat treatment could inactivate synergistically PG only when they were simultaneously carried out. The results from this study can provide theoretical data for the inactivation of PG by ultrasonic treatment in fruit and vegetable juice processing.

In order to explore the effect of high pressure processing (HPP) on the quality of chicken breast batters added with seaweed, such indicators as color, salt-soluble proteins (SSP), cooking loss, water holding capacity, freeze-thaw stability, texture characteristics and rheological properties were studied as a function of pressure level (0.1–500 MPa for 10 min) and holding time (0–25 min at 300 MPa). The results showed that lightness (L*) and whiteness (W) values of low-salt Eucheuma spinosum supplemented chicken batters (LESCB) decreased with pressure up to 200 MPa and then increased. a* value increased gradually with increasing pressure. Pressure in the range of 100 to 300 MPa had no significant influence on SSP (P > 0.05), while SSP decreased significantly with a pressure higher than 300 MPa (P < 0.05). Cooking loss and freeze-thaw loss increased initially and then decreased with pressure up to 300 MPa. Pressure in the range of 100 to 500 MPa improved water-holding capacity significantly compared with low pressure treatment (0.1 MPa) (P < 0.05). Hardness and springiness increased firstly with pressure up to 200–300 MPa and then decreased, and no significant differences were noticed between the 200 and 300 MPa treatment groups (P > 0.05). Compared with the control group (0.1 MPa), HPP could improve the storage modulus (G’) and phase angle (tan δ) of LESCB. The pressure holding time had no significant effect on color, SSP or cooking loss (P > 0.05). Water-holding capacity, G’, tan δ and textural properties were improved with increasing pressure holding time. Hardness and springiness were destroyed when the holding time was prolonged to 25 min. In conclusion, HPP can improve the quality of low-salt chicken batters added with seaweed.

The present study concentrated on the volume expansion mechanism of raspberry fruit chip during microwave heating. To investigate the puffing characteristics of raspberry fruit chips, four-filed coupling models based on the theories of electromagnetic field, heat transfer, structural mechanics and the Transport of Diluted Species physics were established to describe temperature distribution, moisture content and expansion deformation as a function of microwave intensity and initial moisture content, respectively, and they were evaluated by comparison with the experimental results. The results obtained indicated that high pressure inside fruit chips was generated due to water evaporation from the interior during microwave heating, leading to expansion of the chips. On the other hand, water evaporation from the surface resulted in shrinkage of fruit chips. The volume change of raspberry fruit chips was dependent on both expansion and shrinkage. The temperature distribution was mainly dependent on the penetration depth of microwave into the material. The moisture content was decreased gradually with the increase of microwave heating time. The increased elastic modulus of raspberry fruit chips was due to the increase of temperature and the decrease of moisture content, which influenced the volume expansion of fruit chips. Microwave intensity of 20–40 W/g and initial moisture content of 26% gave a better product with a higher expansion percentage of 3.91.

The effect of different drying methods (i.e., hot-air and vacuum freeze drying) on the physicochemical properties and antioxidant activity of okra superfine powder was studied. The results showed significant differences in physical properties (solubility, water holding capacity and bulk density), VC content, chlorophyll content and antioxidant activity between hot-air and vacuum freeze dried samples (P < 0.05). Compared with hot-air dried sample, vacuum freeze dried sample had lower water holding capacity and bulk density, and higher solubility and VC contents and its methanolic extract exhibited stronger antioxidant activity in scavenging 1,1-diphenyl-2-picrylhydrazyl and superoxide anion radicals. There were significant differences in all physicochemical properties except water holding capacity and bulk density among vacuum freeze dried samples of four cultivars four varieties (P < 0.05). The superfine powder of the cultivar Meng 1 had the highest solubility, VC content and antioxidant activity. The superfine powder of vacuum freeze dried okra was superior to its hot-air dried counterpart in terms of physical properties, VC content and antioxidant activity, indicating that vacuum freeze drying was more suitable for the production of superfine powder of okra especially Meng 1, which had higher market value.

In this study, we compared the saturated water solution and ultrasonic methods for the preparation of inclusion complexes of essential oil from Alpinia officinarum Hance with hydroxypropyl-β-cyclodextrin (HP-β-CD). The two methods were evaluated in terms of inclusion efficiency and yield. The inclusion complexes were structurally characterized by microscopy, thin layer chromatography, Fourier transform infrared spectroscopy and ultraviolet (UV) spectroscopy. The hydroxyl radical and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity and reducing power were determined as well as the inhibitory effect on DNA damage, UV-induced hemolysis of red blood cell (RBC) and nitrosamine synthesis. The results showed that the saturated water solution method was considered superior to the ultrasound method, effectively including essential oil into HP-β-CD with little change in chemical constituents. The essential oil and its inclusion complexes had significant hydroxyl and DPPH radical scavenging capacity and high reducing power and were able to protect against DNA damage and inhibit UV-induced hemolysis of RBC and nitrosamine synthesis. The antioxidant ability and the inhibitory effect on nitrosamine synthesis of the essential oil were improved significantly after inclusion (P < 0.05).

Heat moisture treatment was imposed on three kinds of Coix seeds (big Coix seed (BCS), small Coix seed (SCS) and translucent Coix seed (TCS)) to explore the water and heat barrier properties of non-starch components. For this purpose, heat moisture-treated (HMT) Coix seed starches were prepared, and scanning electron microscopy, optical microscope, laser particle analyzer, X-ray diffraction, infrared spectrometry and differential scanning calorimetry were used to explore the impact of HMT of Coix seeds on the morphology, size, structure and thermal properties of starch. The results indicated that HMT caused damage to starch granule surface, increased stomatal size, and weakened birefringence. Meanwhile, the double helix structure and the crystalline and amorphous region were broken, the interaction of starch with itself, and with protein and lipid was reinforced, and the starch molecules were reordered to different degrees. As a result, HMT increased the gelatinization temperature of the starches, weakened crystal heterogeneity, and decreased the energy required for uncoiling. BCS starch was influenced slightly, while TCS starch, rich in amylose, was affected heavily by HMT. Thus, we can apply Coix seed starch more reasonably according to variations in starch properties after HMT.

Objective: This study aimed to clarify the regulatory effect and the mechanism of action of epigallocatechin gallate (EGCG) on cholesterol metabolism in rats. Methods: In vitro cell culture models (Caco-2 cells and BRL hepatocytes) and hyperglycemic rat model were established. In order to determine the possible mechanism for the regulation of cholesterol metabolism in rats by EGCG, the inhibition of bile acids across Caco-2 cell monolayers, the influx and efflux of cholesterol, serum cholesterol level and the expression of lipid metabolism-related genes were evaluated. Results: The transport of sodium glycocholate and sodium taurocholate across Caco-2 cell monolayers was significantly inhibited by EGCG (P < 0.05). EGCG also inhibited the influx of cholesterol in Caco-2 and increased the efflux of cholesterol from rat hepatocytes. The results of animal tests revealed that serum total cholesterol, triglyceride and low-density lipoprotein cholesterol levels were significantly lower in the EGCG-treated group than in the high-fat diet model group (P < 0.05), while high-density lipoprotein cholesterol levels were significantly higher (P < 0.05). Hematoxylin and eosin staining of the rat liver showed that liver steatosis was significantly attenuated by EGCG (P < 0.05). At the molecular level, the mRNA and protein expression of hydroxy methylglutaryl-CoA reductase were significantly decreased in the EGCG-treated group when compared with the model group, while the mRNA and protein expression levels of sterol regulatory element-binding protein-2, liver X receptor α and cholesterol 7α hydroxylase were significantly increased (P < 0.05). Conclusion: EGCG had multiple regulatory effects on cholesterol metabolism, and the underlying mechanism was attributed to the inhibition of bile acid re-absorption, the blocking of cholesterol influx, and the enhancement of cholesterol efflux as well as the regulation of the expression of cholesterol metabolism-related genes.

Objective: The aim of this study was to explore the regulatory effect of Ganoderma atrum polysaccharide (PSG-1) on M1/M2 polarization in lipopolysaccharide (LPS)-simulated mouse macrophages. Methods: Neutral red assay was used to detect macrophage phagocytosis, and flow cytometry analysis was used to determine the level of reactive oxygen species (ROS) and the expression of mannose receptor (MR). Nitric oxide (NO) was analyzed by the Griess method and the levels of interleukin-1β (IL-1β) and IL-10 were determined by enzyme-linked immunosorbent assay (ELISA). Results: Compared to the LPS group, PSG-1 could remarkably reduce macrophage phagocytosis, and inhibit the secretion of IL-1β and NO, but down-regulate the generation of ROS, suggesting that PSG-1 could inhibit LPS-caused macrophage polarization into M1. Meanwhile, significant elevations of MR expression and IL-10 level were observed in the PSG-1 + LPS group compared to LPS group, indicating that PSG-1 promoted macrophage polarization into M2. Further results showed that the inhibitory effect of PSG-1 against LPS-induced inflammatory response was decreased evidently in macrophages by the treatment of anti-MR antibody. Conclusion: PSG-1 has a distinct regulatory effect on LPS-mediated macrophage polarization via inhibiting polarization into M1 and enhancing polarization into M2. Its molecular mechanism may be closely related to the regulation of MR expression on the surface of macrophages.

In order to validate the anti-aging effect of Bama longevity dietary patterns, a mouse model of aging was established by subcutaneously injecting D-galactose (500 mg/(kg·d)) into animals once daily for eight consecutive weeks. Meanwhile, the representative nutrients in Bama longevity dietary patterns (including calorie restriction and intake of VA and soybean isoflavones, dietary fiber and trace elements such as iron, manganese, cobalt and selenium) were selected to design five characteristic diets, calorie restriction, VA and soybean isoflavones, dietary fiber, trace elements and compound diet, for feeding aging mice. The contents of malondialdehyde (MDA) in serum, liver and brain, the activity of total superoxide dismutase (T-SOD) in serum and brain, and total antioxidant capacity (T-AOC) in liver and brain were measured. The results showed that all five diets could inhibit the accumulation of MDA in aging mice, while the activity of antioxidant enzymes and T-AOC were improved when compared with the aging model group. Through positive processing and nondimensionalization, it was found that compound nutrition had the best anti-oxidative stress effect , which could inhibit the accumulation of MDA in serum, liver and brain (P < 0.05), increase the activity of T-SOD by 12.33% (P < 0.05), and significantly increase the activity of T-AOC in liver by 35.35% (P < 0.05). A comprehensive evaluation showed that the antiaging effect of 5 diets followed the decreasing order of compound diet > VA and soybean isoflavones > calorie restriction > dietary fiber > trace elements. These results demonstrate that the Bama longevity diet pattern has a significant protective effect against oxidative stress in D-galactose-induced aging mice, indicating its great development potential.

Objective: Cod skin collagen peptide (CSCP) has a good protective effect on liver injury, but the absorption mechanism of CSCP is still not clear. In this study, the Caco-2 cell monolayer model was used to investigate the absorption mechanism of CSCP in order to provide an experimental basis for the study of the absorption mechanism of CSCP in the animal intestine. Methods: The stability of CSCP in artificial gastric juice, artificial intestinal juice, different pH conditions, and Caco-2 cell monolayers were evaluated. Subsequently, the highest concentration of CSCP in the transport experiment was determined by using cell counting kit-8 (CCK-8) assay. The Caco-2 cell monolayer model was established, and its compactness, integrity and polarization were evaluated by measuring transepithelial electrical resistance and the activity of alkaline phosphatase. The effects of transport time, CSCP concentration, vrapamil, MK-571, phenylarsine oxide and odium deoxycholate on the transport efficiency were investigated by using reversed-phase high performance liquid chromatography to determine CSCP concentration and calculating apparent permeability coefficients and accumulated transport of CSCP. Results: CSCP was relatively stable in artificial gastric juice, artificial intestinal juice, different pH conditions and Caco-2 cell monolayers for 3 h. No polypeptides were found to be hydrolyzed during the transport process. The transport of CSCP was positively correlated to the transport time and CSCP concentration and was not affected by addition of verapamil or phenylarsine oxide. In the presence of sodium deoxycholate and MK-571, the transport of CSCP was significantly promoted (P < 0.05). Conclusion: The mechanism of CSCP transport across Caco-2 cell monolayer was related to cell bypass and CSCP efflux was mediated by multidrug resistance proteins.

The aim of this study was to evaluate the structural characteristics and anti-diabetic mechanism of tea polysaccharides, dietary ingredients used for the management of diabetes. A water-soluble polysaccharide was isolated and purified from mature tea leaves, and its monosaccharide composition and molecular mass were measured. Also, its structural characteristics were analyzed by ultraviolet (UV) and infrared (IR) spectroscopy were. Alloxan was injected into ICR mice to induce non-obese type diabetes. The diabetic rats were treated with the polysaccharide (100 mg/(kg·d)) or glibenclamide (positive control) for 42 days. The fasting blood glucose, serum insulin and total antioxidant parameters in serum and liver were determined. The pancreas was examined by haematoxylineosin staining and β-cells were observed using a microscope. The results showed that the molecular mass of the polysaccharide was 119 600 Da, which was composed of glucuronic acid, rhamnose, fucose, arabinose, xylose, mannose, glucose and galactose with a molar ratio of 32.61:1.00:5.46:8.13:3.84:2.37:15.36:7.52. Based on the UV and IR spectra, it seemed likely that the polysaccharide was a non-protein-bound pyran-type heteropolysaccharide. The treatment of the diabetic rats with the polysaccharide significantly elevated liver glycogen content, and decreased blood glucose to normal from 18.98 mmol/L, but exhibited no significant difference in pancreatic and plasma insulin levels compared with the normal group (P > 0.05). Moreover, treatment with the polysaccharide significantly increased superoxide dismutase activity compared with the model group (P < 0.05), but showed nitricoxide synthase activity and malonaldehyde content in liver close to those of the negative group; however, a significant decrease in nitric oxide in liver was found in comparison with the model group (P < 0.05). The effect of the polysaccharide was similar to that of glibenclamide. Histopathological and morphological results demonstrated that pancreatic β-cells and liver tissue morphology in the polysaccharide treated group were restored to normal. Thus, this study suggests that the tea polysaccharide exerts anti-diabetic effects by improving insulin secretion, β-cell function, and antioxidant status.

Antioxidant peptides were purified from millet protein hydrolysate by sequential column chromatographies on Sephadex G-25 and DEAE-32. Cellulose acetate electrophoresis was used to determine the purity of the purified peptides. The antioxidant effect was investigated by detecting radical scavenging activity against superoxide anion, hydroxyl and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. In order to investigate the protective effect of the antioxidant peptides on islet cells, an INS-1 cell model of oxidative stress induced by H2O2 was used. The 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl- 2-H-tetrazolium bromide method was applied to detect the cell viability, flow cytometry was used to detect the cell apoptosis, and real-time polymerase chain reaction was employed to analyze the gene expression of antioxidant enzymes. The results showed that the peptides were purified to electrophoretic homogeneity. The percentage scavenging of superoxide anion, hydroxyl and DPPH radicals by the peptides were (62.71 ± 3.86)%, (73.56 ± 4.51)% and (82.62 ± 5.25)%, respectively. The peptides could significantly promote cell viability, reduce the level of cellular reactive oxygen species, and inhibit cell apoptosis (P < 0.05). The mechanism may be related to the up-regulated expression of antioxidant enzymes including superoxide dismutase 1, catalase enzymes, glutathione S-transferases, and quinone oxidoreductase 1. This study conclusively demonstrated that the antioxidant peptides from millet showed a significant protection against oxidative stress induced by H2O2 in INS-1 cells.

The effect of ginger extract on antioxidant and phase II detoxifying enzymes in mice exposed to benzo(α)pyrene (BαP) was investigated and the underlying regulatory mechanism was elucidated. Kunming mice were administered by gavage with ginger extract at 100 (low-dose group, LG), 200 (medium-dose group, MG) and 400 mg/(kg·d) (high-dose group, HG) for 14 consecutive days before intraperitoneal injection with 50 mg/(kg·d) of BαP. Glutathione peroxidase (GSHPx), catalase (CAT), superoxide dismutase (SOD), quinone reductase (QR), hemooxygenase 1 (HO-1) and glutathione-Stransferase (GST) activity and their protein and mRNA expression were analyzed. The expression levels of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and Kelch like ECH-associated protein 1 (Keap1) were examined as well. Results showed that BαP + MG and BαP + HG significantly (P < 0.05) elevated CAT and GSH-Px activities in the serum and CAT, SOD and GSH-Px activities in the liver and kidney in mice compared to BαP alone. Meanwhile, the administration of BαP + MG and BαP + HG led to a significant increase of QR, HO-1 and GST activity by 21.7%, 23.99% and 32.40% in liver, and by 29.05%, 56.39% and 15.08% in kidney, respectively. In contrast to BαP, BαP + MG treatment led to a 21.9% increase of Nrf2 protein expression and a 34.7% reduction of Keap1 protein expression. Totally, 19 compounds were identified in ginger extract by high performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometry (HPLC/LTQ- Orbitrap-MS). Our results suggest that ginger extract was able to induce antioxidant and phase II enzymes in mice exposed to BαP by a mechanism related to Nrf2-Keap1 signaling pathway.

Antarctic krill (Euphausia superba) is a new and important marine resource. The safety for human consumption of Antarctic krill and its products has gained extensive attention. Particularly, the application of Antarctic krill oil in healthy products and dietary supplements is limited due to its relatively high total arsenic content. In this study, total arsenic and inorganic arsenic contents of Antarctic krill and its products were analyzed respectively by hydride generation-atomic fluorescence spectrometry and liquid chromatography-atomic fluorescence spectrometry, and on the basis of the data obtained together with Antarctic krill consumption data, the dietary arsenic exposure and the safety of consumption of Antarctic krill products were assessed by the point estimation method. The results showed that total arsenic contents were less than 0.50 mg/kg in whole shrimp and meat, but relatively high in Antarctic krill powder, Antarctic krill oil and its capsule products, and that inorganic arsenic contents of Antarctic krill and its products were generally less than 0.050 mg/kg. The dietary exposure level of inorganic arsenic from Antarctic krill oil was negligible. Long-term consumption of Antarctic krill oil would not increase total dietary intake of inorganic arsenic. Therefore, Antarctic krill and its products can be widely used as a safe and high-quality ingredient in foods, feed and healthcare products.

The nutritional components and molecular mass distribution of the peptides prepared from the eggs and body wall of Apostichopus japonicus were detected, and then their effects on spleen lymphopoiesis and immune function in mice were evaluated. Four peptides from the eggs and body wall of sea cucumber were prepared by enzymatic hydrolysis and crossflow ultrafiltration. Mouse spleen lymphocyte proliferation (SLP) in vitro in the presence of each of the peptides (10, 50, 100 and 500 μg/mL) was measured by the sulforhodamine B colorimetric method. Furthermore, mice were subjected to oral gavage with each of the four peptides at low, middle and high dosages (83.3, 166.7 and 500.0 mg/kg) for 30 consecutive days. Those given water were used as a control group. After the experiments, organ/body mass ratio, delayed-type hypersensitivity, T lymphocyte proliferation induced by concanavalin A, the number of antibodyforming cells, serum hemolysin formation, carbon clearance capability, chicken red blood cell phagocytosis by mouse macrophages and natural killer cell activity were measured. The results showed that EP1 and BWP1 (1–10 kDa) at 500 μg/mL had a significant effect on SLP. The crude protein contents of EP1 and BWP1 were 64.74 and 70.25 g/100 g, the total amino acids were 45.69 and 63.26 g/100 g, and the molecular mass distribution was 130–1 600 and 130–2 500 Da, respectively. After the mice were orally administered with different doses of the peptides for 30 days, both EP1 and BWP1 enhanced monocyte-derived macrophage phagocytosis; EP1 improved cellular immune function while BWP1 augmented humoral immune function. In summary, EP1 and BWP1 from the eggs and body wall from Apostichopus japonicus had immunoenhancing effects and could be developed as new immunomodulatory products.

In this study, a polysaccharide named AAP-10 was isolated from Auricularia auricula-judge from Longquan region of Zhejiang province by hot water extraction and stepwise ethanol precipitation. Physicochemical analyses were used to characterize the polysaccharide. Furthermore, this study evaluated the immunomodulatory effect of polysaccharide AAP-10 in a mouse model of immunosuppression induced by cyclophosphamide (CPA). Results indicated that AAP-10 had high purity and was a homogeneous polysaccharide. Monosaccharide composition analysis showed that AAP-10 was mainly composed of glucose and mannose at a molar ratio of 6:1 as determined by high performance liquid chromatography with precolumn derivatization with 1-phenyl-3-methyl-5-pyrazolone. High-performance gel-permeation chromatography analysis showed that the average molecular mass of AAP-10 was 6.56 × 105 Da. Moreover, the negative effect of CPA on body mass and spleen of immunosuppressed mice was improved by AAP-10 administration at a certain dose. In addition, AAP-10 enhanced the proliferation of splenic lymphocytes and natural killer cell activity, as well as mononuclear macrophage phagocytosis, especially at low and intermediate doses (2.5 and 5.0 mg/(kg·d)). These results showed that AAP-10 had good immunoregulatory effect in immunosuppressed mice.

Objective: To observe whether schisandrin B (SCB) can improve D-galactose-induced learning and memory impairment in aging mice. Methods: ICR mice were randomly divided into normal control group (intragastrically administered with distilled water and subcutaneously injected with normal saline), aging model group (intragastrically administered with distilled water and subcutaneously injected with 220 mg/kg D-galactose), SCB (M) group (intragastrically administered with 20 mg/kg SCB and subcutaneously injected with 220 mg/kg D-galactose), and SCB (C) group (intragastrically administered with 20 mg/kg SCB and subcutaneously injected with normal saline). The administration lasted for 7 weeks. Step-through test and Morris water maze test were applied to observe the effect of SCB on the learning and memory capacity of mice. The superoxide dismutase (SOD) activity in the brain tissue of mice was detected by the WST-1 method and the malondialdehyde (MDA) content was measured by the TBA method. The mRNA and protein expression of p19, p53 and p21 genes were detected by quantitative real-time PCR and Western blot, respectively. Results: SCB could significantly improve the learning and memory ability of D-galactose-induced aging mice, increase the SOD activity in the brain tissue, decrease the MDA level, and reduce the expression of p19, p53 and p21 genes. Conclusion: SCB can improve brain aging induced by D-galactose in mice, and the mechanism may be related to the increased antioxidant capacity and the decreased expression of p19, p53 and p21 genes in the brain tissue of mice.

In order to investigate the effect of co-ingestion of 5 vegetables, including pakchoi, cauliflower, eggplant, green bean and wax gourd, on acute glycemic response to rice meals, the postprandial blood glucose level within 4 h were measured in 21 healthy subjects after consuming a mixed meal of 300 g each of above vegetables and rice. The results showed that the glycemic scores of vegetable-rice mixed meal within 1 h were 46.26%, 63.17%, 45.94%, 45.49% and 54.47% for cauliflower and rice meal (C+R), wax gourd and rice meal (W+R), pakchoi and rice meal (P+R), eggplant and rice meal (E+R) and green bean and rice meal (B+R) when taking rice meal (R) as the reference. Compared with R, P+R meal elicited the significantly lower peak value and the maximum amplitude glycemic expedition within 4 h (MAGE240) (P < 0.05). For all vegetable-rice meals except for W+R, the areas under glycemic response curve calculated on per gram of available carbohydrate (iAUCCHO) in the first 1, 2 and 3 hours were significantly lower than that of R (P < 0.05). The intake time was negatively correlated with iAUC, peak value and MAGE240. In conclusion, incorporating 300 g vegetables into rice meals, especially pakchoi, cauliflower and eggplant, could decrease intake time and attenuate glycemic response.

In an effort to comprehensively evaluate changes in the antioxidant activity of fresh-cut Chinese water chestnut during surface etiolation, changes in surface color, flavonoid content and in vitro antioxidant capacity were determined during the storage of fresh-cut Chinese water chestnut. The results indicated that suface flavonoid content increased quickly during etiolation. On the other hand, at the later stage of storage, flavonoid content decreased because of the occurrence of browning. Consequently, the antioxidant capacity increased with storage time, and it reached the maximum level when b* value was the highest, and then remained stable. The statistical analysis showed that b* value had a significant correlation with flavonoid content, 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2’-azinobis (3-ehtylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), hydroxyl radical scavenging capacity, ferric reducing antioxidant power (FRAP) and total reducing power (P < 0.01). Similarly, flavonoid content was significantly correlated with DPPH and ABTS+· scavenging capacity, FRAP and total reducing power (P < 0.01). These results indicated that flavonoid content and antioxidant capacity of fresh-cut Chinese water chestnut surface increased due to the occurrence of etiolation.

The aims of this study were to compare the compositions and metabolic functions of the bacterial communities on mackerel and large yellow croaker during refrigerated storage by Illumina MiSeq sequencing and phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt). The results showed that the richness of bacteria on mackerel surface was increased while the bacterial diversity was decreased during prolonged storage; however, no significant change was observed for large yellow croaker. Psychrobacter and Shewanella were the dominant bacteria on mackerel and large yellow croaker, respectively, and their relative abundance was positively correlated with total volatile basic nitrogen (TVB-N) contents (r = 0.709, P < 0.001 for mackerel; r = 0.600, P = 0.008 for large yellow croaker), respectively. This may suggest that Psychrobacter is the specific spoilage organism (SSO) on mackerel, while Shewanella is the SSO on large yellow croaker. The relative abundance of genes related to the metabolism of amino acids such as methionine, tyrosine and histidine on mackerel was higher than that on large yellow croaker at the same storage period (P < 0.05). This may partially explain why mackerel is more perishable than large yellow croaker based on the metabolic levels of the bacterial communities. This study provides a basis for adopting targeted strategy to the preservation of different aquatic products.

Postharvest kiwifruits (Actinidia chinensis) ‘Huayou’ were grouped and dipped in 0, 0.05, 0.10, 0.20 or 0.50 mmol/L melatonin (MT) solution for 10 min at room temperature, and then stored at (0.0 ± 0.5) ℃ (90%–95% relative humidity) for 90 d. The results showed that compared with other treatment groups, 0.10 mmol/L MT apparently delayed the decline of kiwifruit firmness and color L* value, effectively reduced the respiration rate and ethylene production rate and kept lower mass loss rate and decay incidence during storage. Compared with the control, 0.10 mmol/L MT reduced the activity of amylase, delayed the decline of starch contents, maintained higher superoxide dismutase, ascorbate peroxidase and glutathione reductase activity, increased the peak of catalase, and significantly increased the contents of ascorbic acid and glutathione. These results suggested that pre-storage application with 0.10 mmol/L MT retarded the ripening and senescence of kiwifruits under low temperature storage conditions.

In the present study, we aimed to develop a method to diagnose the incubation period and symptom appearance of potato dry rot using time series hyperspectral imaging based on dynamic time warping (DTW). The symptom features during the development of dry rot were analyzed and extracted. The time series key point, namely the start point of symptom appearance was analyzed by DTW clustering algorithm based on the time series characteristics. The threshold segmentation algorithm was used to extract the region of interest (ROI) during the data preprocessing, and the probability density algorithm was applied to eliminate the abnormal spectral data. By comparison of the spectra and appearance of potatoes during the development of dry rot, non-monotonic characteristics were observed in the spectra. Further, the spectral characteristics were extracted by kernel principal component analysis (KPCA). Finally, the time series key point was predicted by using fuzzy clustering model (FCM) based on the symptoms features with an accuracy of only 66.7%. By contrast, the prediction accuracy of DTW on the basis of time series features was as high as 94.4%. This study confirmed that the time series hyperspectral imaging based on DTW could effectively diagnose the symptom appearance of potato dry rot.

This study was intended to isolate, purify, and identify the pathogens that can cause etiolation and browning in fresh-cut broccoli during storage and to screen plant essential oils for their effectiveness in controlling these pathogenic isolates. A pathogenic fungal strain (AB01) was obtained. According to the phylogenetic tree constructed based on the internal transcribed spacer (ITS) region in it, AB01 was identified as Alternaria alternata. The inhibitory effects of six plant essential oils including cinnamon, fennel, bovine, clove, thyme and citronella oils against AB01 were tested both in vitro and in vivo in order to select the optimum oil species and concentration. The results showed that cinnamon essential oil possessed the best antimicrobial effect with a minimum inhibitory concentration (MIC) of 0.05 μL/mL and minimum fungicidal concentration (MFC) of 0.15 μL/mL, followed by fennel and oregano oils. Cinnamon essential oil at 0.15 μL/mL could effectively reduce both etiolation and browning in fresh-cut broccoli.

Measuring food safety index objectively, promoting the effective disclosure of food quality information, scientifically guiding consumer food purchasing behaviors and enterprise business activities and compelling local governments to toughen supervision over food safety are important measures to solve the problem of food safety by a market-led mechanism. In this article, we present a method for measuring food safety index on a five-graded scale based on the concept of the cask effect and the Golden Section, and we also quantitatively measure the situation of food safety in China based on the food inspection data in the third and fourth quarter of 2016 and in the first and second quarter of 2017 issued by the China Food and Drug Administration. It is shown that the values of food safety index for these four quarters are 279, 280, 264 and 290 within the safe range, suggesting that the situation of food safety is overall stable. We suggest that the government should step up efforts to strengthen areas of weakness with a focus on the supervision of the quality and safety of starch, starch-based products and vegetable products and particularly prevent the threat posed by food additives abuse to food quality and safety. Finally, we conclude with some suggestions on compiling and releasing food safety index.

Fruit wine is a yeast-fermented low alcohol beverage, whose taste and flavor are directly affected by the selection of yeasts. Due to the diversity and differential metabolic characteristics of yeasts, the fermentation of fruit wine with mixed strains has aroused widespread concern. However, the interaction of yeasts during mixed culture fermentation affects their growth and metabolite production, and further affects wine quality. In this paper, the types and functions of fruit wine yeasts are summarized. The focus is on reviewing recent advances in the effect of environmental stress on the mixed culture fermentation and the interaction of fruit wine yeasts. This article aims to provide theoretical support for mixed culture fermentation of fruit wine with yeasts so as to improve the quality of fruit wine.

Purines are natural substances found in all cells of the body and in virtually all foods, usually existing in foods in chemically combined form. In the body, the final product of purine metabolism is uric acid. However, too high intake of purine-rich foods can increase the level of serum uric acid, which results in hyperuricemia and even gout. With the economic development and the changes in people’s diet structure, the prevalence of hyperuricemia and gout has increased year by year. This paper systematically reviews the methods used for the detection of purine in foods as well as the distribution of purine in different foods and the changes of purine in foods during storage and processing. Meanwhile, future prospects in this area are proposed. It is expected that this review will provide a theoretical basis for developing new purine detection technologies and low-purine foods and eventually reducing gout prevalence.

In recent years, due to increasingly severe heavy metal pollution in soils, rivers and oceans, the presence of excessive harmful heavy metals in seafood is widespread in China, which seriously affects the safety of seafood for culinary and medicinal use. Therefore, the removal of harmful heavy metals from seafood is of wide research interest. This article focuses on reviewing two methods to remove harmful heavy metals from seafood, namely purifying the organism when it is alive and removing heavy metals from seafood protein hydrolysate. Moreover, future trends in the development of new methods are discussed.

Lactic acid bacteria (LAB) starter cultures prepared by freeze-drying exhibit the advantages of high viability, activity and genetic stability. But the freeze-drying process usually has some undesirable effects. In this paper, the changes in cell membrane permeability, cell membrane fluidity, enzymes, proteins and genetic materials during freeze-drying are analyzed to elaborate systematically the injury mechanisms of freeze-dried LAB. As results, it is concluded that the mechanism by which freeze-drying causes physiological damages to LAB is mainly attributed to four aspects: the formation of ice crystals and the phase transition of phospholipids, leading to increased membrane permeability; the alteration of cell membrane fatty acid composition, influencing cell membrane fluidity; the decrease of enzyme activity and the denaturation of related proteins, affecting cell growth and metabolic rates; the structural changes of DNA-binding proteins, and the rupture of the hydrogen bonding between base pairs, resulting in the destruction of DNA supercoiling. These physiological damages may lead to decrease in the viability of lactic acid bacteria, or even cell death.

With the characteristics of high efficiency, low energy consumption and low cost, high moisture extrusion technology is currently one of the most promising food processing technologies. High moisture textured protein obtained by high moisture extrusion has a structure similar to animal muscle and can be eaten directly without rehydration, which can be widely used in meat products, frozen foods and snacks. This paper reviews recent progress in studying the extrusion parameters used for the quality control of high moisture extrusion textured protein. The focus is on reviewing the methods to evaluate the quality of high moisture texturized vegetable protein, and future prospects for the application of high moisture texturized protein are also discussed.

Aroma is an important parameter for measuring the sensory quality of brandy. The types and contents of aroma substances play a decisive role in the style and typology of brandy. The aroma contents in brandy are affected by the raw materials, and the fermentation, distillation and the oak aging processes. In this paper, the variety aroma, fermentation and distillation aroma and aroma of oak aging are the main lines. The aroma composition and the factors influencing aroma formation in brandy are reviewed in order to provide some useful information for further study of brandy in the future.

Intestinal barrier dysfunction is associated with some chronic metabolic diseases, such as obesity and diabetes. Akkermansia muciniphlia, a mucin-degrading bacterium that resides in the mucus layer, is closely related to intestinal barrier function. Significant changes in the abundance of this bacterium in clinical cases and some animal models of metabolic diseases suggest its possible involvement in the progression of metabolic diseases. However, the exact mechanism of action remains to be clarified. This article reviews recent advances in the relationship of A. muciniphlia with the intestinal mucus layer, metabolic diseases and intestinal immunity, and also attempts to elucidate the influence and mechanism of action of this bacterium on intestinal barrier function. It is hoped that this review will provide new insights into dietary prevention of chronic metabolic diseases.

Zanthoxylum L. is a genus of plants with high medicinal value that contains a variety of bioactive ingredients. This paper reviews the active components of Zanthoxylum L. including volatile oil, alkaloids, lignans and coumarins which have been reported in the literature since 2010. The antibacterial, antitumor and analgesic effects of these components are briefly summarized and the prospects for their medicinal application are discussed. It is expected that this review will provides a theoretical basis for further development and utilization of Zanthoxylum.

Obesity as a major public health concern all over the world not only causes high medication cost, but also has a series of side effects on health. Currently, the application of natural products such as plant phenolic compounds is considered as a promising alternative to conventional medication in the management and treatment of obesity. A large number of studies have confirmed that phenolic compounds can inhibit lipogenesis and have a significant anti-obesity effect. Therefore, in order to improve obese patients’ health awareness, the various classes of phenolic compounds and their absorption pathways in the body as well as the mechanism behind the inhibition of lipogenesis and obesity by these compounds are reviewed in this article.

In recent years, growing attention has been paid to the nutritional properties and health benefits of grain-derived traditional vinegar, which is closely related to chemical components in vinegar. Due to the complexity of the raw materials and the manufacturing process, the chemical composition of traditional vinegar are very complicated. Amino acids, organic acids, polyalcohols, sugars, flavonoids, volatile compounds, melanoidins, and inorganic elements have been reported as chemical constituents from vinegar. This article summarizes and reviews the recent studies on chemical components in grainderived traditional vinegar. We hope that this review can provide valuable information for establishing more specialized indexes in vinegar quality standard and promoting the development and utilization of vinegar.

Odor activity value (OAV) is an effective technological means for characterizing the contribution of key aroma components to the aroma of foods in the dimensions of concentration and threshold and has been widely used in the characterization of key aroma components in foods. This article summaries the recent progress in the application of OAV in fermented products, fruits, vegetable oil, and so on. Meanwhile, problems existing in current studies are discussed and possible solutions of the problems are proposed as well as future prospects for the application of OAV in the characterization of key aroma components in foods and aroma blending.