Abstract:In recent years， with the rapid development of food industry， it is a big challenge to achieve high-quality food process， which is required for food safety， sensory and nutrition as well as for the reduction of energy consumption. Due to the illustration of food processing and the improvement of computer performance gradually， many phenomenon during processing such as heat and mass transfer， chemical reactions and local effects， could be described by mathematical modelling and simulation. It is the basis of the precise control and energy saving for food engineering. Therefore， we summarized the progress of food systems and processes relating to modeling and simulation. This review aimed at promoting the application and development of digital technology in food processing.

Abstract:In recent years， antioxidant peptides with high safety， potent antioxidant capacity， become a hot research field. This research is mainly engaged in oxidative stress inhibitory activity of egg white peptides. This study takes the pepsin hydrolysates from egg white ovomucin as raw materials， and pentapeptides from egg white as research object. The antioxidant activity of pentapeptides from egg white protein were evaluated using different chemical methods with different mechanisms. The pentapeptide CFDVF showed extraordinary DPPH scavenging activity （50.14% ± 2.1% at the concentration of 1.0 mmol/L）， VYQFL exhibited the strongest ABTS free radical scavenging ability [TEAC value = （94.66 ± 0.37） μmol/L TE/100 μmol/L]， WNWAD showed extraordinary oxygen radical absorption capacity [ORAC value = （2.53 ± 0.18） μmol/L TE/μmol/L]. Secondly， in order to further examine the antioxidant activity of pentapeptides from egg white， the oxidative stress model of HEK293 cells was established by MTS assay. WNWAD （Trp-Asn-Trp-Ala-Asp） exhibited the strongest oxidative stress inhibitory activity. The pentapeptides showed no stimulatory or cytotoxic effects in HEK293 cells. Finally， the WNWAD was screened out to carry out the research on mechanism of pentapeptides from egg white against oxidative stress in human embryonic kidney 293 cells. The MDA production and cellular activity of LDH， CAT， T-SOD， and GSH-PX were measured by kits. The results showed that WNWAD inhibited cell oxidative stress by increasing intracellular LDH activity and reducing intracellular MDA content. Enzyme activity results displayed that WNWAD dose-dependently increased the activity of SOD1， CAT and GPx1 in HEK293 cells. The effect of WNWAD on the protein expression of SOD1， CAT and GPx1 in HEK293 cells was analyzed with western blotting. Compared to the control， a concentration-dependent up regulation of SOD1， CAT and GPx1 protein expression by the WNWAD could be seen.

Abstract:This study explored the effect of water extract of mulberry leaf on lipid metabolism， to illuminate its’ lipid-lowering mechanism. Giving high-fat mice different dosage mulberry leaf water extract for 8，12 and 16 weeks， then collected their blood and livers to determine the level of blood lipid and the activity of enzymes by kits. Male mice were given high dosage mulberry leaf water extract for 12 weeks， its level of blood lipid returned to normal. Compared with HFC group， the rate of weight-gain were decreased by 22.52%， abdominal fat factors were decreased by 32.67%， contents of TC， TG， LDL-C in serum were decreased by 41.29%， 36.60% and 31.28% respectively， contents of HDL in serum were increased by 47.20%， activity of FAS in liver were decreased by 23.99%， activity of LPL， HL in liver were increased by 21.22% and 32.91%. Female mice were given high dosage mulberry leaf water extract for 8 weeks， its level of blood lipid returned to normal. Compared with HFC group，the rate of weight-gain were decreased by 26.58%， abdominal fat factors were decreased by 40.74%， contents of TC， TG， LDL-C in serum were decreased by 42.53%，41.75% and 29.33% respectively， contents of HDL in serum were increased by 22.46%， activity of FAS in liver were decreased by 22.49%， activity of HSL in liver were increased by 31.98%. Giving high-fat mice mulberry leaf water extract for a certain period， which can inhibit fat synthesis and accelerate fat decompose， to reduce fat accumulation and improve the level of blood lipid.

Abstract:To study the neuroprotective effect of inulin-type oligosaccharides extracted from yacon （YOs）， the antioxidant activity in vitro and cytoprotective effect were applied. The antioxidant activity of YOs was evaluated by the DPPH radical scavenging capacity， ABTS radical scavenging capacity and the ferric reducing antioxidant power （FRAP） assays. The cytoprotective effect was evaluated by H2O2-induced SH-SY5Y injured cells model. The results of antioxidant activity showed the IC50 of DPPH and ABTS were（0.272±0.078） mg/mL， equivalent to（141.01 ± 15.67） Trolox μmol/g YOs， 2.67 ± 0.89 mg/mL， equivalent to（195.81±8.13） Trolox μmol/g YOs， respectively， and the FRAP value was （10.12±0.35） mmol/g， equivalent to （82.40±1.59） Trolox μmol/g YOs. In addition， YOs （0.5 and 1 mg/mL） significantly restored the injury on SH-SY5Y induced by H2O2 （200 μmol/L）. In conclusion， YOs possess good antioxidant activities and significant cytoprotective effect against oxidative stress injury on SH-SY5Y cells， which suggests it’s prospective in preventing or forestalling brain aging.

Abstract:Anti-obesity effect of Pteridium aquilinum and its mechanism was investigated by measuring its inhibitory effect against 3T3-L1 preadipocyte differentiation and high fat diet induced C57BL/6J obese mice. The differentiation of 3T3-L1 cells was induced and Oil Red O staining was used to analyze the effect of Pteridium aquilinum ethanol extract （PAE） on the differentiation of 3T3-L1 preadipocytes. To elucidate the mechanism of PAE， we performed Western blot for the expression of genes related with adipogenesis （PPARγ， CEBPα， SREBP-1c） and lipogenesis （FAS， ACC）. C57BL/6J mice were induced by high fat diet for 6 weeks. Obese C57BL/6J mice were then randomly divided into high-fat diet group （HFD） and the 1%PAE group （HFD+PAE）. In addition， C57BL/6J mice fed with normal diet were selected as the normal diet group （ND）. After 8 weeks， the body weight， glucose metabolism indications （blood glucose， glucose tolerance） and serum lipid levels （TG， TC） in all mice were evaluated. The results showed that PAE suppressed 3T3-L1 adipocyte differentiation and reduced the accumulation of fat in adipocytes. Treatment of PAE markedly suppressed the protein expression of PPARγ， CEBPα and SREBP-1c， as well as FAS and ACC （P<0.05）， which are the key transcription factors and metabolic enzymes in adipogenesis and lipogenesis. After 8-weeks feeding， the indicator in HFD group were high than ND group， including body weight， body fat deposition， serum glucose and serum lipid （P<0.05）. Treatment with PAE significantly decreased the body weight， blood glucose and the levels of serum TC， TG. PAE also effectively improved impaired glucose tolerance （P<0.05）. In conclusion， Pteridium aquilinum suppressed 3T3-L1 adipocyte differentiation， inhibited obesity， hyperglycemia， hyperlipemia and improved impaired glucose tolerance in C57BL/6J obese mice. These effects might be closed related to its inhibition of genes expression regulating adipogenesis and lipogenesis.

Abstract:The immunoregulatory and antioxidant activities of polyphenols from black tea on H22-bearing mice were investigated. These mice were simultaneously administrated by gavage with black tea polyphenols at different dosages [250 mg/（kg·d） and 500 mg/（kg·d）] for 35 days and inoculated with H22 cells on day 14. After the last administration, the tumor inhibition rate, immune organ indexes, proliferation ability of splenocytes（T and B lymphocytes）, splenic NK cell killing activity and phagocytosis of peritoneal macrophages were measured. The levels of interleukin-2 （IL-2）, interferon-γ （IFN-γ）, tumor necrosis factor-α（TNF-α） in serums and activities of superoxide dismutase （SOD） and glutathione peroxidase （GSH-Px）, and the contents of malondialdehyde （MDA） in livers were measured by using commercial reagent kits. The results showed that black tea polyphenols significantly inhibited H22 hepatoma cells growth in mice, the tumor inhibition rate was 46.04% in the low-dose group [250 mg/（kg·d）] and 63.32% in the high-dose group [500 mg/(kg·d）] at the end of the experimental period. Compared with the model group, black tea polyphenols could significantly promote splenocyte proliferation, killing activity of NK cells, and macrophage phagocytosis（P<0.05）. In addition, the ratio of T cells in peripheral blood, the levels of IL-2, IFN-γ, TNF-α in serum and the activities of SOD, GSH-Px in liver were significantly increased （P<0.05) in the high-dose group, while MDA levels were significantly reduced （P<0.05）. In conclusion, the black tea polyphenols exhibit a strong antitumor activity in vivo. The underlying mechanism might be related to enhancing antitumor immune response and improving antioxidant function in the body.

Abstract:The xylanase produced by strain L10608 has good hydrolysis properties when hydrolyzed substrate of xylan. The xylanase gene（xyn-GH10 and xyn-GH11） of L10608 was obtained by nested PCR. The xylanase gene （xyn-GH10 and xyn-GH11） was obtained by nested PCR， then the bioinformatics analysis was performed. The xyn-GH10 has a total length of 1 469 bp， molecular weight： 50.677 ku； theoretical pI： 7.98； It predicted that the xylanase signal peptide is MGIQALPRAAVRQKLRTPLPALAAGVLGLTAALVPPTNADA by Signal4.0； the xylanase protein sequence has distinct family 10 glycoside hydrolase sarcina barrel conserved region catalysis domain， and encoded a non-catalytic section RicinB-lectin domain consists of 108 amino acids. xyn-GH11 full length is 729 bp； molecular weight： 24.003 ku； theoretical pI： 8.98； It predicted that the xylanase signal peptide is MHQDGSQQDRTQNPAPFGGLSRRGFLVGGTGAAALAAGSGLLLPGTAHAA by signal 4.0. The xylanase protein sequence has a distinct “right-hand” conserved region of the family 11 of glycoside hydrolases. The xyn-GH10 activity was 160 U/mL， and the activity of xyl-GH11 was 55 U/mL.

Abstract:The stability of meat emulsion is significantly related to the myofibrillar protein content， the specific ways of stabilizing oil/ water emulsions by myofibrillar proteins under different protein volume fraction（1%， 5%， 10%） were investigated. Analysis of the stability of emulsions show differences in the protein concentration， when protein volume fraction were 5% and 10%， the stability of emulsion was significantly increased （P<0.05）， the particle size was 1-10 μm， the amount of protein adsorption and oil-holding capacity were increased significantly （P<0.05）. In addition， the oxidation of fresh emulsion （1%， 5%， 10%） was effectively inhibited by the interface protein membrane， which also being an important way for oil-holding capacity of the emulsion （1%）. In contrast， when protein volume fraction was high （5%， 10%）， the oil-holding capacity of emulsions were improved by interface adsorbed myofibrillar protein and gel matrix.

Abstract:Flavonoids and bonito protein hydrolysates were prepared respectively using rhizoma smilacis glabrae and bonito fish as raw materials. The Flavonoids from rhizoma smilacis glabrae was screened with the index of flavone extraction rate， 1，1-diphenyl-2-picrylhydrazyl free radical （DPPH·） scavenging activities and xanthine oxidase （XOD） inhibitory activity. The hydrolytic enzyme was optimized with the index of protein recovery rate， DPPH· scavenging activities， XOD inhibitory activity and the amino acid analysis of the optimal bonito protein hydrolysates. The effect of interaction between flavonoids extracts from rhizoma smilacis glabrae and bonito protein hydrolysates on antioxidant activity and XOD inhibitory activities was examined. Then investigation the mechanism of the interactions of flavonoids and peptide using fluorescence spectroscopy. The results demonstrated that flavonoids extracted by ethanol showed higher flavonoids recovery rates， DPPH· scavenging activities and XOD activity than aqueous extract. The optimum hydrolytic enzyme of bonito fish is papain. It was observed that the XOD activity of flavonoids-peptide complexes was significantly increased， and the antioxidant capacity showed significant synergistic effect. DPPH· scavenging activities of flavonoids-peptide complexes was slightly improved in pasteurization， while significantly decreased in high temperature sterilization. At pH 6.0， DPPH· scavenging activities was greater than that of pH 5.5 and 6.5. After fluorescence spectrum analysis， flavonoids may through hydrogen bonding with bonito protein hydrolysates to form new compounds.

Abstract:Using Spirulina powder as raw material， the optimal extraction conditions of Spirulina polysaccharide were investigated. The inhibitory effect， type and mechanism of Spirulina polysaccharide inhibition on tyrosinase were studied by enzyme kinetics， and the antioxidant capacity of Spirulina polysaccharide was evaluated by DPPH free radical method. Studies have shown that the best extraction effect of Spirulina polysaccharide could be obtained under the conditions of extraction time 2 h， the ratio of material to liquid is 1∶40， the extraction temperature is 90 °C， and the pH 8 is controlled to obtain the best extraction effect of Spirulina polysaccharide. The results of enzyme kinetics show that Spirulina polysaccharide It has a significant inhibitory effect on tyrosinase， and its IC50 is 1.193 mg/mL. Its inhibitory effect is reversible mixed inhibition， and its inhibition constant KI is 0.544 mg/mL. Spirulina polysaccharide showed a good scavenging effect on DPPH free radicals with an IC50 of 0.463 g/L and a free radical scavenging capacity of 83.24% of L-ascorbic acid at the same concentration.

Abstract:In order to study the effect of structure of chelated peptides of Channa argus and antioxidant activity， the chelated peptides particle size， zeta potential， structure and antioxidant activity were analyzed. The relationship between structure and antioxidant activity were determined. The results showed that the particle size of calcium chelated peptides and iron chelated peptides were significantly smaller， but zinc chelated peptides were similar to that of the peptide. The absolute value of zeta potential of chelated peptide was higher than that of short peptide， and the structure of chelated peptide was more stable. The contents of hydrophilic amino acids and antioxidant amino acids were increased， and the highest content of antioxidant amino acids was presented in iron chelated peptides. The characteristic absorption peaks of the chelated peptides and the short peptide showed that the binding degree of the different ions to the short peptide and the amino group. Electron microscopic showed that ions and short peptides were adsorbed together， and the adsorption of iron chelated peptides was the strongest. DPPH， H2O2 and O2-· showed different antioxidant activity and reducing capacity of chelated peptides due to different structures. Antioxidant activity of iron chelated peptides was strongest， and other chelated peptides have stronger antioxidant activity than that of short peptides. Antioxidant activity of chelated peptide and chelated rate have positively correlated relationship.

Abstract:To illustrate the distribution of chromium （Ⅲ） in the formation of GTF and further reveal the mechanism of chromium rich， this study applied advanced materials science analysis method and biological electron microscope technology. The morphological changes of Saccharomyces cerevisiae were monitored by scanning electron microscope and transmission electron microscope. The distribution in Saccharomyces cerevisiae was revealed by dispersive energy spectrometer-transmission electron microscope （EDS-TEM） and time-of-flight two ion mass spectrometer （TOF-SIMS）. The content of Cr3+ in various parts of Saccharomyces cerevisiae was detected by EDTA elution and enzymolysis. The result shows that with the increase of Cr3+ mass concentration in the fermentation medium， the shape of Saccharomyces cerevisiae changed from regular ellipse to irregular. And when the mass concentration of Cr3+ was high up to 500 μg/mL， the surface precipitation occurs， and the inner cavity appears cavitation. The total chromium and organic chromium content were highest in Saccharomyces cerevisiae， reaching 1 803.87 μg/g·DCW and 1 133.91 μg/g·DCW respectively， when the mass concentration of Cr3+ was 500 μg/mL. 14.43% of the total chromium adsorbed was concentrated in the cell wall， and the other 85.57% was enriched in the protoplasts. In addition， 73.29% of the adsorbed chromium existed as organic chromium in the protoplasts. GTF is mainly formed in the protoplast and only a small amount of inorganic chromium was adsorbed by cell wall of Saccharomyces cerevisiae. And the mass ratio between protoplasts and cell walls is about 5 ∶ 1， we can draw a conclusion that the distribution of GTF in the cell wall or protoplast is approximately homogeneous in Saccharomyces cerevisiae. The results of EDS-TEM and TOF-SIMS further confirms this conclusion.

Abstract:The effect of soybean soluble dietary fibers （SSDF） with molecular weight of 27.8 ku for HSSDF and of 9.3 ku for LSSDF on short-term retrogradation （4 h） and long-term retrogradation （14 d） of rice starch （RS） were investigated by employing dynamic rheometry， X-ray diffraction， Fourier transform infrared spectroscopy（FTIR）， differential scanning calorimetry （DSC） and scanning electron microscopy （SEM）. The result showed that the addition of SSDF could significantly reduce the increase of elastic modulus of starch system during short-term retrogradation and increase the viscosity of starch gel. The inhibition effect of HSSDF on short-term retrogradation of RS was more pronounced. The △Hr values of RS-SSDF system was significantly lower than RS. The effect of HSSDF and LSSDF on the △Hr values of rice starch showed no significant difference. The typical B-type crystallinity of rice starch formed when stored at 4 ℃ for 7 d. Results of FTIR and XRD indicated that the relative crystallinity of rice system was decreased by adding SSDF， especially the HSSDF. Compared with the compact structure of rice starch formed in the aging process， obvious cavity structure was formed in RS-SSDF blends， showing a honeycomb structure. Different molecular weight SSDF（27.8 ku and 9.3 ku），especially the HSSDF， had a inhibition effect on short-term retrogradation and long-term retrogradation of RS.

Abstract:An attempt has been made to investigate the influence of high temperature and relative humanity（80 ℃， 85%） during drying on the quality properties of Chinese dried noodles （CDNs） in order to improve the drying process and product quality. Wheat variety Yongliang 4 was used to make CDNs in laboratory and relative properties were evaluated. The experiment was designed with two factors at three levels for the drying conditions with varying drying temperatures （40， 60 ℃ and 80 ℃） and relative humidity （65%， 75% and 85%）. The drying time was 300 minutes. The product properties including color （CIE L*， a*， and b*）， density， shrinkage ratio and texture properties （bending strength， break distance and break work） of CDNs were measured. The results showed that moisture content of noodle products significantly changed with the increase of temperature. Drying temperature affected b* value and density very significantly （P＜0.01）， changed shrinkage ratio， break distance and break work remarkably （P＜0.05）， while it had no influence on L* value， a* value and bending strength. Relative humidity altered color （L*， a* and b* value）， density and texture properties of CDNs significantly. The factor interaction significantly effected b* value and bending properties. Compared to drying temperature， the relative humidity had a greater influence on the quality of the noodles during the drying process. While comparing with the normal drying method （40 ℃， 75%）， it was observed that product properties of CDNs including b* value， bending strength， breaking distance and break work increased significantly at high temperature and humidity （80 ℃， 85%）. However， no significant changes were found in L* value， a* value， density and shrinkage ratio in both methods. From the present results， it can be concluded that high temperature and relative humanity drying technology should be matched with the design of drying equipment， thermal energy loss， energy consumption analysis and product characteristic evaluation， so as to finally determine its application value in the actual production of noodles.

Abstract:The effect of different spray-drying temperature （130 ℃/65 ℃， 160 ℃/78 ℃， 180 ℃/90 ℃） on the physicochemical property and structure of micellar casein powder （MCP） have been investigated. The results showed that the microstructure change was insignificant and the flow index was good at temperature of 130 ℃/65 ℃. As the increase of spray drying temperature from 130 ℃/65 ℃ to 180 ℃/90 ℃， the MPC surface become rough， the D50 of MCP reduced from 14.13 μm to 10.47 μm， the solubility of MCP reduced from 84.14% to 60.44%， the moisture content reduced from 4.07% to 3.20%， and the flow index reduced from 4.16 to 1.27. In generally， 130 ℃/65 ℃ was proper temperature of spray drying.

Abstract:According to the composition and distribution of Tibet yak ghee （yak butter），1，3-dioleic acid， 2-palmitoate triglyceride （OPO） structural lipid and rice bran oil， we used physical mixing to complement their structure and prepare a human milk fat substitutes similar to the composition and structure of human milk fatty acid. The Lingo model was first used to fit the solution in this process， and the optimal molar ratio was Yak butter ∶ OPO structural lipid ∶ rice bran oil = 0.30 ∶ 0.36 ∶ 0.15. The results showed that the ratio of total fatty acid， sn-2 fatty acid and PUFA was 89.4%， 65.3% and 99.8% respectively， which were higher similar to human milk fat. It means that yak butter is an excellent raw material for the preparation of human milk fat substitutes.

Abstract:Monascus is a key fungus in Hongqu rice wine brewing system， which plays an important role in the color， aroma， taste and healthy function of the rice wine. However， the number of Monascus in the brewing process is gradually decreased， and its inhibition mechanism factor is still unknown. In order to explore the growth inhibitory factors of Monascus in the process of brewing of Hongqu rice wine， PCR-DGGE and qPCR were used to track the changes of Monascus and other dominant fungi in the traditional brewing process. The possible reasons were deduced according to the change of the amount of Monascus and were verified by the corresponding systems. The results showed that the Monascus and Saccharomyces cerevisiae were the dominant bacteria in the traditional brewing process， and the amount of Monascus decreased gradually with the brewing. The validation system indicated that the growth of Monascus could not significantly inhibit by a temporary decrease in dissolved oxygen content， the physical constraint of Hongqu and the soluble substances of Hongqu. However， increased alcohol content is the key factor affecting the growth of Monascus. The relationship between the growth change of alcohol and Monascus was further verified by the traditional brewing process. At the very beginning， the alcoholic content （0 to 4%， volume fraction） had no effect on Monascus. With the increase of alcohol content， the growth of Monascus was gradually inhibited. When the alcohol content reached 17% （volume fraction）， Monascus was significantly inhibited. Therefore， this study demonstrates that the production of alcohol is the main factor inhibiting the growth of Monascus in the fermentation process.

Abstract:The effects of infrared radiation combined with heat preservation on the pasteurization of grape seed were studied by catalytic infrared radiation technique. The results showed that the total number of bacteria in the grape seed decreased rapidly with the increase of the infrared radiation time and the holding time. After 98 s of infrared radiation and then holding at 75 ℃ for 60 min， the total number of bacteria in the grape seed decreased to 1.66 lg （CFU/g， which was 43.14% lower than that of grape seeds treated by infrared radiation only and 65.99% lower than that of the untreated grape seeds. The a* values and b* values of grape seeds were 12.31-13.48 and 13.22-14.47， respectively. The color difference （E） was 2.14-5.26， which indicated that the color change of grape seeds was small after infrared radiation treatment. The extraction rate of grape seed oil increased with the increase of temperature and the holding time， and the oil yield of grape seeds could rise to 10.39% （d.b.）， which was 46.96% higher than that of untreated grape seeds. In the present study， the oil acid values， peroxide values and iodine values of grape seeds were all in accordance with FAO's standard. Consequently， the highest rate of bacteria reduction and the highest oil yield of grape seeds were obtained， and the color of the grape seeds was kept well when the grape seeds were treated with 75 s of infrared radiation and holding at 75 ℃ for 60 min.

Abstract:The general objective of the present work was to assess the applicability of pressure-transform tumbling curing assisted by ultrasound （PTU） technique for improving the curing effect in duck processing. For this purpose， the effect of PTU on duck protein denaturation， structure changes of myofibrillar proteins and moisture distribution was investigated and was compared with those of obtained with raw duck （untreatment） or vacuum tumbling （VT）. Indexes such as degradation of protein， changes of protein structures and water states of different treatment samples were analyzed. Results showed that with the increasement of PTU treatment time， the amount of macromolecular myofibrillar proteins degraded， the amount of MHC （myosin heavy chain）， desmin， troponin T， tropomyosin were decreased gradually. At the same time， some small molecule protein fragments appeared. Raman spectroscopy was used to analyze the changes of protein spatial structures. The results showed that the proportion of α-helix was reduced greatly （P<0.05）， and the amount of β-sheet， β-turn and random coil were increased （P<0.05） after PTU treatment. The LF-NMR data indicated that the position of the component T21 and T22 were clearly prolonged relaxation times by tumbling. Moreover，the proportion of peak area of T21 and T22 were significantly increased （P<0.05）， especially for PTU treatment， which indicated that the water molecules combined with protein more tightly and parts of free water turned into immobilized water. The results can provide the theoretic basis for the PTU technology in the meat industry and related equipment design.

Abstract:Snail’s mucus contains abundant natural collagen， elastin， urine membrane element， protein， vitamins， glycolic acid. In this paper， the snail secretion was extracted by method of NaCl stimulus. The contents of crude protein in the mucus were determined by the Kjeldah Method. The results show that the crude protein of the mucus was about 0.42% in fresh snail mucus， while crude protein content was 31.48% in freeze-dried samples. The collagen of mucus was measured by the UV pectrophotometer and the presence of type I collagen in snail mucus was proved by Fourier-transform infrared spectroscopy （FT-IR）. The content of collagen determined by Woessner method was about 16.69%. HPLC separation was developed for the determination of simultaneous quantitative analysis of allantoin and glycolic acid in snail mucus. Finally， it was found that snail mucus had bacteriostatic activity against Shigella， Salmonella suis， Pasteurella avium and Staphylococcus aureus. This study will contribute to the research in the field of food， cosmetics and pharmaceutical and application.

Abstract:The purification conditions of red raspberry seed flavonoids by polyamide was studied， also identified its activity of vitro hypolipidemic. On the basis of the purification of AB-8 macroporous resin， polyamide was used for secondary purification， then evaluated its ability of bile salt-binding. The optimal purification conditions of polyamide resin as followed： sample concentration was 5.5 mg/mL， sample volume was 100 mL， the sample flow rate was 2.0 mL/min and sample pH was 4.5. Then the volume fraction of the ethanol was 60%， the volume of elution was 150 mL， and the flow rate of elution was 1.5 mL/min. The purity of red raspberry seed flavonoids was 48.19% and increased by 23.12%. The half maximal inhibitory concentration of flaconoids in binding sodium cholate sodium taurocholate and glycocholate was 2.911， 3.779， 3.257 mg/mL. Thus red raspberry seed flavonoids have good binding capacity with bile salts and are a natural herb with hypolipidemic activities.

Abstract:Objection: For better understanding of texture change of high pressure processed fruits and vegetables during pressure come-up time and its extended storage. Method： Hardness of carrot subjected to high pressure（100-600 MPa， 0-2 min） was evaluated， and two-week storage was carried out to record hardness change. Potential mechanism of hardness softening was analyzed based on cell membrane integrity， cellular microstructure as well as enzymatic degradation and fractions conversion of pectin material. Result： Results showed that pressurization more than 200 MPa caused significant hardness loss（P<0.05）， with only 37.7% hardness remained after 300 MPa treatment. There was no dramatic hardness change during 0-2 min pressure holding time， neither in the process of storage. Relative electrolyte leakage increased with pressure rise， which indicates increase in membrane permeability. Microstructure observation by transmission electron microscopy showed that high pressure processing led to cell deformation. Membrane rupture， cells collapsed were observed at 400， 600 MPa respectively. With the effect of high pressure processing， cell separation and cell wall degradation during the period of two-week storage at 4 ℃ were promoted. Pectin methylesterase and polygalacturonase remained considerable activities. Content of water soluble pectin decreased significantly（P<0.05)， resulting conversion to chelator， sodium carbonate soluble pectin. Conclusion: The main cause of softening of carrot was mechanical damage of cell membrane brought by high pressure processing， but conversion of pectin fractions benefited hardness retention within storage duration.

Abstract:Objective： In order to find rapid assessment of critical point temperature for cold shock treatment and low temperature storage. Method： After pak choy （Brassica rapa var chinensis） dipped in different temperatures of cold water， the leaves were measured by chlorophyll fluorescence analyzer， and the osmosis and diffusion amount of potassium （K+）， calcium （Ca2+） and sodium （Na+） were determined by ion electrodes. Result： Pak choy was dipped in cold （or salt） water for 1 min， all fluorescence data did not significantly change until treatment temperature dropped to -4 ℃. Obviously， the dipping time of 1 min for judging chilling injury temperature was not enough. When pak choys were treated with 0 ℃ water for 10 min， all parameters had significantly changed. Especially， ETR and qP had extremely significant decrease， while Y（NO） was significant increase. When pak choys were treated with 2 ℃ water for 10 min， all fluorescence data did not show significantly change， so 2 ℃ was identified as a non-hazardous temperature， and treatment for 10 min was enough time for judging chilling injury temperature， but not enough for judging cold shock response temperature. When leaves treated by 2 ℃ water for 30 min， Stern-Volmer type NPQ and qN were significantly increased， and obvious cold shock response were observed. The diffusion and osmosis content of K+ treated with 0 ℃ water for 30 min were extremely significantly higher than that of 4 ℃ （P<0.01）， which showed that cell membrane leakage was exacerbated， and pak choy might suffered chilling injury at 0 ℃. The diffusion amounts of Ca2+ from pak choy treated with 0-2 ℃ was exceeded than that of 4 ℃， which meant low temperature might induce the changes of the calcium binding capacity of cell walls. The diffusion of Na+ decreased with the dropping of temperature， and Na+ of 0 ℃ treatment was significantly lower than that of 4 ℃ （P<0.05）. Conclusion： ETR data and diffusion and osmosis content of K+ can be used as parameters for judging chilly injury temperature， NPQ and qN can be used as parameters for judging the temperature and time of cold shock treatment. Low temperature damage could be found by 0 ℃ water treatment for 10 min or 30 min. Pak choy laid at 0 ℃ for Long-term storage will suffer chilling injury， 2 ℃ water treatment for 30 min will induce cold shock response and pak choy can be safely stored at the temperature， 1 ℃ was the critical point of two temperatures.

Abstract:The Sensory evaluation， pH， TVB-N， histamine and diversity of bacterial communities associated with chub mackerel under modified-atmosphere packaging （MAP， 50%CO2 / 50%N2） and vacuum packaging （VP） conditions were investigated in this study. Firstly， the seneory study showed the shelf life of chub mackerel were 16 and 12 days under MAP and VP conditions when stored at 4 ℃. Then， metagenomic analyses based on high-throughput sequencing of bacterial V4 16S rDNA hypervariable region revealed a selection of specific bacteria during spoilage under different packaging. In VP samples， Photobacterium， Shewanella and Vibrio were the dominant microorganisms at the end of shelf life， whereas Pelagibacteraceae， Halomonadaceae， and Psychrobacter spp. were the major spoiling microorganisms in MAP chub mackerel fillets. These data provided us with valuable information about microbiological spoilage of chub mackerel fillets under MAP and VP， which might help us to develop appropriate methods to improve the quality and safety of chub mackerel products.

Abstract:Objective： Complex plant-source extracts of large yellow croaker （Pseudosciaena crocea） during ice storage were optimized by response surface methodology. Methods： TVB-N value of large yellow croaker （Pseudosciaena crocea） with different plant-source extract treatments during ice storage can be measured and the optimum concentration of Ginkgo biloba leaves extract （GBLE）， Bamboo vinegar （BV） and tea polyphenol （TP） on large yellow croaker （Pseudosciaena crocea） during ice storage were measured by single-factor experiment respectively， the optimal ratio of complex plant-source extracts were analyzed by response surface methodology. Results： The optimal mass fraction of GBLE， BV and TP were 0.5%， 0.5% and 1.5% respectively. The interaction of BV and TP solution had significant effect on TVB-N value （P<0.05）， the optimal ratio of three kinds of plant-source bio-preservatives was 1.38% of GBLE， 0.92% of BV and 0.85% of TP. Conclusion： The predicted value of TVB-N was 47.17 mg N/100 g and the measured value was 50.80 mg N/100 g. Therefore， the response surface regression model was reliable.

Abstract:Objective： A large number of bacteria in infant formula have been inactivated， but they still have adverse effects on the quality and shelf life of products. The traditional pure culture only can detect the viable bacteria， so evaluating the microbial contamination in infant formula by Metagenome strategy is essential and makes up for the disadvantage. Methods： Microbial contamination of six infant formula were evaluated by pure culture， PacBio SMRT （single molecule real-time） and ddPCR （droplet digital PCR）. Results： Coliform groups， Salmonella， Staphylococcus aureus， Enterobacter sakazakii and spores were absent in the infant formula samples by traditional pure culture. A total of 14 bacterial phylum， 138 bacterial genus and 255 bacterial species were identified in infant formula， and psychrotrophic bacteria Bacillus cereus that might affect the product shelf life were at some point present in the infant formula samples， the average relative abundance were up to 23.54%. A low relative abundance of Escherichia coli were detected in the IF3， IF4， IF5 and IF6 infant formula samples， and the relative abundance was 0.06%， 0.01%， 0.15% and 0.05%， respectively. The results of ddPCR showed that the copy numbers after taking the logarithm of Bacillus cereus and Escherichia coli were 5.45 and 4.89， respectively. Conclusion： There were no pathogens were detected in six infant formula， in line with national standards. But Bacillus cereus and Escherichia coli that might affect the product shelf life were at some point present in the infant formula samples. This study combined with multiple technologies to fully assess the microbial contamination in infant formula， establish microbial detection method of infant formula.

Abstract:Based on CNAS-CL07： 2011， the uncertainty for biotin microbiological assay in formula refer to GB 5009.259－2016 should be evaluated. According to JJF1059.1-2012 and GB/Z22553-2010， the sources of uncertainty for the method were explored. The evaluation involves repeatability of measurement， weighing of sample and sample dilution， standard solution preparation， standard curve fitting and measured deviation of UV-Visible spectrophotometer. By analysis， the heft of uncertainty and expanded uncertainty were calculated. The content of biotin in cereal meal for infant was （32.49 ± 2.64） μg/100 g， P = 95%， k = 2. The most significant factor that contributed to the determination of biotin was microbiological factors， they were shown in standard curve fitting and repeatability of measurement.

Abstract:After lactose and fat， human milk oligosaccharides （HMOs） are the third most abundant nutrient in human milk. They are very important for the healthy growth of infants. A quantitative method has been developed and validated for the determination of 6 main HMOs in human milk， including 3-fucosyllactose （3-FL）， 2’-fucosyllactose （2’-FL）， lacto-N-neotetraose （LNnT）， lacto-N-tetraose （LNT）， 6’-sialyllactose （6’-SL） and 3’-sialyllactose （3’-SL）， by ion chromatography（IC）. In addition， another active compound sialic acid （Neu5Ac） in human milk could be determined at the same time. A portion of human milk sample was diluted by water and subjected to IC analysis after filtration. Water， sodium hydroxide solution， and sodium acetate solution were used as mobile phase. CarboPacTM PA-1 analytical column and pulsed amperometric detector （PAD） were adopted for IC separation and detection， respectively. The method validation results showed a good linearity（r>0.999） in the analytical range for all the 7 analytes. The limit of detection （LOD， 3 s/n） and limit of quantitation（LOQ） of the method for each analyte were 5.2， 0.4， 2.8， 2.5， 1.0， 1.8， 0.5 mg/L human milk and 19.8， 9.8， 19.9， 19.7， 9.9， 9.9， 5.0 mg/L human milk， respectively. The analytical range and LOQ meet detection requirements of all types of human milk samples including the secretory and non-secretory three-stage human milk. The recovery of each analyte in human milk were all within 90.3%-107.3% （n=6） with a good precision （RSD%<3.7%， n=6）. This method provides a simple and fast approach for the accurate determination of HMOs and free sialic acid in human milk.

Abstract:In this paper， the changes of polysaccharide content in the ultrasonic extraction process were studied. At the same time， the spectral information of the extraction process was collected by near-infrared in situ real-time monitoring technique. The mathematical model was established by the relationship between spectral information and chemical value. The results showed that the content of polysaccharide increased in the process of ultrasonic extraction and then fluctuated in 60 min. After pretreatment of the acquired primitive spectra， SG was the most efficient pretreatment method with the highest Rc， Rp value and the least RMSECV， RMSEP in all pretreatments. After modeling with PLS， iPLS and si-PLS methods， the model established by si-PLS method is the best， which combined four optimal wavelength ranges are 1 258.591-1 316.735 nm， 2 027.121-2 084.226 nm， 2 153.93-2 210.888 nm and 2 337.239-2 387.696 nm. Under the optimum model， the Rc， Rp were 0.9621， 0.9667 and RMSECV， RMSEP were 0.0116， 0.0137， respectively. In conclusion： the near-infrared spectroscopy can be used to predict the content of polysaccharide in the ultrasonic extraction of maca polysaccharide and the in-situ monitoring during the extraction process is realized.

Abstract:In this study， the composition of the carotenoids produced by two haloarchaeal strains was identified by ultraviolet/ visible spectroscopy （UV-vis）， thin layer chromatography （TLC） and high-performance liquid chromatography-tandem mass spectrometry （HPLC-MS/MS）. The antioxidant activities of the purified main carotenoid components were then studied. The major carotenoids of Hrr. lipolyticum included bacterioruberin （BR） （84.91%）， monoanhydrobacterioruberin （MABR） （7.87%） and bisanhydrobacterioruberin （BABR） （4.03%）， while those of Srr. litoreum included BR （94.86%） and MABR （1.17%）. The major carotenoid constituents （BR， MABR and BABR） were isolated and purified by column chromatography on silica gel. They all possessed dose-dependent scavenging activities against DPPH and hydroxyl radicals， which were significantly higher than those of β-carotene. It suggested that the C50 carotenoids from halophilic archaea possessed high antioxidant activities. This study provided basis for the exploitation and application of natural carotenoid resources.

Abstract:A QuEChERS pretreatment coupled to liquid chromatography-quadrupole-time of flight mass spectrometry （LC-Q-TOF-MS） method was established for identification and quantification of 24 illicit anti-inflammatory and sedative drugs in the health food. The illicit drugs in samples were accepted with the QuEChERS， comparing with the solvent extraction. The quantitative analysis was based on the accurate mass of protonated/ deprotonated molecular ion， isotopic pattern， a priori known retention time， and high resolution fragment ion spectrum with information dependent acquisition. The result showed that the established LC-Q-TOF-MS was an effective analytical method for the simultaneous characterization and quantification of anti-inflammatory and sedative drugs with high selectivity， a high linearity （r2>0.999） in wide range， low LOD and LOQ， and high recoveries （81.8%-103%）。

Abstract:The aim of the study was to develop a method for the determination of Shigella by real-time RPA. Based on the conserved sequence of invasive plasmid antigen （ipaH） of Shigella， designed specific primer and exo probe， and used to monitor the performance of reaction system by detection equipment， the RPA reaction was performed successfully at 39 ℃ and the results were obtained with 20 min. This method could be specifically detected Shigella， and could not detect non-Shigella bacteria. The study showed that the detection limit of exo-RPA was 1.0×10-3 ng/μL with genomic DNA of Shigella， which was the same as the real-time PCR published articles. For artificially contaminated chicken and broccoli samples with the bacterial concentration of 9 CFU/25 g， the Shigella coule be detected after 8 hours culture by real-time RPA. The result of real-time RPA， which was the same as real-time PCR， but detected need 7-12 min by real-time RPA， and detected at least 35 min by real-time PCR （the Ct was between 27 and 34）. The Shigella real-time RPA assay developed in the study was specificity， high sensitivity， simple and rapid， and provided a new technology platform for detection of Shigella.

Abstract:In this study， establish an efficient method to assess the eating quality of cooking-soybean by principal component analysis（PCA） combined with partial least squares（PLS）. Taking hardness， gumminess and sensory core of post-cooked-soybean as dependent variables， main factors influence on eating quality of cooking-soybean were screened for principal component analysis by the correlation coefficient and the variable importance value of the projected （VIP） of each component conducted by PLS model with the indexes of physicochemical properties， water absorption rate and swelling rate after soaking of soybean as variations. Results showed that： calcium content， 7S globular， soluble sugar content and swelling rate were screened out by PLS， which had a major impact on the texture quality of post-cooked soybean. Four principal components obtained by PCA， which could reflect most details on eating quality of cooking-soybean with a cumulative contribution rate of 73.374%. The hardness， gumminess， 7S， 11S/7S and total Ca were the main factors affecting the eating quality of cooking-soybean on the basis of contribution rate of each principal component. The quality of different varieties on eating quality of cooking-soybean was comprehensively evaluated by using the principal component comprehensive score model. Five suitable soybean varieties suitable for cooking and processing were selected as follows： Heinong85， Hefeng55， JD149， Suinong42 and Dongnong251.

Abstract:The geographical discriminations of 104 Longjing tea samples collected from three tea-producing areas （Xihulongjing tea-producing area， Qiantanglongjing tea-producing area and Yuezhoulongjing tea-producing area） were studied based on HPLC fingerprints combined with stoichiometric determination analysis. The characteristic chromatograms of Longjing teas were constructed by HPLC-DAD detection， which showed that the reference fingerprints were composed of 28 characteristic common peaks including 16 known components and 12 unknown components. The geographical-recognition accuracies of Longjing teas exceeded 90% by Discriminant Factor Analysis（DFA）， Multilayer Perceptron （MLP） and Support Vector Machine （SVM）， especially by SVM with the accuracy of 98.08%. In conclusion， this study indicated it was feasible for geographical discrimination by multiple HPLC fingerprints combining with chemometrics methods.

Abstract:Snakehead were treated by different preservatives （pepper extract， Jerusalem artichoke extract and nobilis protamine）， the volatile components of snakehead were determined using headspace solid-phase microextraction gas chromatography mass spectrometry （HS-SPME/GC-MS） combined with the electronic nose， microbiological index and thiobarbituric acid value. The results of HS-SPME-GC-MS showed that 107， 118， 103 and 97 volatile compounds were identified in blank group and samples treated with pepper extract， Jerusalem artichoke extract and nobilis protamine， respectively. During storage period， the trend of volatile components in blank group was in accordance with the treatment groups. Besides， the volatile components of aldehyde， ketone and alcohols decreased continuously， while amine showed an increasing trend. Acids and other substances exhibited obvious fluctuation. Moreover， the treatment samples （Jerusalem artichoke extract and nobilis protamine） were less rich in volatile compounds compared with the blank group， and nobilis protamine resulted in the most signifcant reduction in the number of volatile compounds and peak area. The results of electronic nose showed that the response value of the protamine group was lower than control group during the later storage period， indicating that nobilis protamine could delay flavor deterioration in chilled black fish fillets effectively. Microbial and TBA results showed that microbiological index and TBA value of treatment group were lower than the blank group， the group effect of protamine treatment can inhibit microbial growth and reproduction， slow microbial decomposition of fat， protein， thereby reducing the storage of low-grade aldehyde， ketone and other undesirable flavor produced.

Abstract:Using 25 Hongqu rice from Fujian province as the raw materials， this study investigated the correlation between the characteristic parameters by multivariate statistical method， including pH， dry weight loss， bulk density， starch， protein， total amino acids， liquefaction， saccharification， fermentation （3 d）， alcohol production and the total acid in the fermented products， and then established the regression model. The results showed that saccharification， liquefaction and fermentation （3 d） have the largest variation coefficients. Both correlation and partial correlation between the pH， fermentation（3 d） and product acidities showed significant or extremely significant levels. The regression equations between the product acidity （Y） and pH （x1）， bulk density （x2）， starch （x3）， protein （x4）， liquefied force （x5）， fermentation （3 d）（x6）， wine production （x7） was as follow： y=-206.6614+40.55114x1+8.9631x6+1.16790x7+0.1086x1x5-0.9471x1x6-0.2151x1x7-0.0002x2x3+0.0002x2x5+0.0244x3x5-0.0768x3x6+0.0264x4x5-0.1749x4x6+0.0233x5x6-0.0101x5x7（R=0.9894， P=0.0001）， while the important factors were pH， fermentation（3 d） and alcohol production， the single factor regression equation between the product acidity （Y） and the three factors were significant or extremely significant level respectively.

Abstract:Lactic acid bacteria （LAB） is one of the important industrial microorganisms. And LAB are also beneficial microorganisms in the intestine， which have the effect of improving the gastrointestinal environment and maintaining the balance of intestinal flora. The emergence of genome-wide association study （GWAS） provide more reliable degree of evidence and new ideas for the separation， traceability and evolutionary research for the LAB. This paper briefly describes the necessities of LAB molecular biology research， introduces the history of GWAS and the current situation of its application in bacteria， and looks forward to the application of this technology in LAB research， as well as the difficulties will be encountered in the future and solutions will be provided.

Abstract:Obesity is one of the most serious global health problems. Regardless of obesity has an adverse impact on human somatotype and mentality， it can increase the risk of other different chronic diseases， such as cardiovascular disease， diabetes mellitus type II and hypertension. A growing number of scientific studies and epidemiological surveys show that flavonoids are a large class of nature polyphenols without side effect and have the actual activity of fat-lowering and weight-losing. In this paper， based on the latest research， related obesity characteristics， relationship of obesity and chronic inflammation， structure and source of flavonoids， metabolism kinetics and molecular mechanisms of the anti-obesity had been discussed. The research and development suggestion of weight-losing products main containing dietary flavonoids was also put forward， in order to offer a diet of precise dietary interventions for an increasingly large number of overweight and obese groups.

Abstract:Pectin is a nature plant polysaccharide， has extremely complex structure and versatile function. The wide use of pectin as an ingredient， high value food additive and health care product， which imparts rheological and textural properties to various products （food， medicine， health products and cosmetics）. Ag nanoparticles （AgNPs） have broad-spectrum antibacterial properties and low toxicity to mammalian cells， which have been widely recognized and applied. This review looks to the techniques for pectin extraction from plant sources and preparation of Ag nanoparticles in foreign major journals for the past few years. Aims to providing more active references and beneficial lessons for new pectin resources， green extraction techniques and new pectin products in China.

Abstract:Antimicrobial peptides， widely distributed in nature， are characteristics of broad antimicrobial spectrum， strong and selective killing ability and fast speed of action. They have potential application prospects in the fields of clinical study， pharmaceuticals industry， livestock breeding， aquaculture and food industries. However， antimicrobial peptides have two drawbacks hampering their applications. First， the antimicrobial activity is relatively weak compared with antibiotics； second， the hemolytic activity and stability are difficult to be regulated. In order to obtain efficient， stable and safe antimicrobial peptides， structural modification of antimicrobial peptides is necessary. In this paper， the relationship between the structure and function of antimicrobial peptides was briefly introduced， and the regulatory factors influencing the activity of antimicrobial peptides， such as the positive charge， hydrophobicity， amphipathy， helicity and special amino acids were mainly elaborated， which provides effective ideas for targeted designing of natural antibacterial peptides.

Abstract:Genetically modified soybean oil has ranked the largest edible vegetable oil in China. Scientific and reasonable labeling regulations enable the right to know the transgenic soybean oil， guarantee the freedom of choice for consumers and promote a healthy and orderly soybean oil market. To guaranty the implementation of these regulations， analytical methodologies allowing accurate determination of genetically modified soybean oil are demanded. DNA analysispresentsa high sensitivity， specificity and durability compared to chemical analyses and proteins analyses which lack a reliable performance with highly processed samples. The DNA extraction protocols and PCR amplification were systematically summarized to promote a successful genetic characterization. At last， the DNA degradation caused by the oil refining process was reviewed.