Abstract:Oxygen is toxic effect on Bifidobacteria. The viability of the cells is greatly affected， therefore， hindering its production and application. In order to improve the oxygen tolerance of Bfidobacteria， this experiment used the method of changing the partial pressure of oxygen in liquid medium to carry out the oxygen-tolerant domestication of Bifidobacterium animalis subsp. lactis Probio-M8. The effect of oxygen on Bifidobacterium animalis subsp. lactis Probio-M8 was evaluated by measuring physiological characteristics， oxygen tolerance， and cell membrane fluidity. After oxygen-tolerant if domestication 1 000 generations of growth when the aerobic and anaerobic environment， the pH of culture medium decreased significantly by 0.23 and 0.27（P<0.05）， and the acid production capacity increased significantly. The relative bacterial growth ratio （RBGR） and NADH oxidase activity increased significantly by 0.47 and 31.14 U （P<0.05）， and the oxygen tolerance was significantly enhanced. The unsaturated fatty acid content increased significantly by 17.26% （P<0.05）， and the cell membrane fluidity was enhanced. After oxygen-tolerant domestication， the oxygen tolerance of Bifidobacterium animalis subsp. lactis Probio-M8 was significantly enhanced， which provided ideas for its application and development in food.

Abstract:C-Phycocyanin （C-PC） is a type of widely recognized natural food colorant. It is also a kind of important functional food， possessing anti-inflammatory， antioxidant， and antineoplastic properties. Our previous study demonstrated that C-Phycocyanin could induce the apoptosis of non-small cell lung cancer（NSCLC） H1299 cells. In this study， we employed high-throughput transcriptome method to analyze the differential genes between phycocyanin treated and untreated H1299 cells， aiming at investigating the potential regulatory mechanism of phycocyanin in NSCLC cells. The results showed that phycocyanin could significantly suppress the expression of toll/interleukin-1 receptor domain-containing adapter protein （TIRAP） gene in H1299 cells. siRNA knockdown of TIRAP expression induced the abnormal changes of cellular morphology， cell proliferation ability decreasing， upregulation of Bax， and downregulation of Bcl-xL. Furthermore， siRNA knockdown TIRAP could also significantly inhibit the activity of NF-κB signaling in H1299 cells. The present study demonstrated that phycocyanin could induce the apoptosis of H1299 cells through downregulating TIRAP expression. This work have revealed the potential regulatory mechanism of phycocyanin in NSCLC cells， also provided the theoretical basis of lung cancer treatment and functional foods application.

Abstract:Oxidation is an important reason for the decline of quality of the aquatic products during processing and storage. In this study， we oxidized（0， 3， 6， 9 and 12 h） sea cucumber （Stichopus japonicus） myofibrillar proteins in different hydroxyl radical-generated system （0.01 mol/L FeCl3 / 0.1 mol/L VC / 10 mmol/L H2O2 and 0.01 mol/L FeCl3 / 0.1 mol/L VC / 50 mmol/L H2O2）. Then the indicators related to protein oxidation were evaluated. The aggregation of the protein was determined by electrophoresis and the microstructure of protein was observed using cold field scanning electron microscopy. The results indicated that when the concentration of H2O2 was 10 mmol/L and 50 mmol/L， the carbonyl content reached （4.31±0.32） nmol/mg protein and （3.72±0.30） nmol/mg protein at 3 h and 12 h. The content of free-SH decreased from 0 h （12.17 ± 0.54） μmol/g protein to 12 h （7.27 ± 0.52） μmol/g protein and （6.64 ± 0.17） μmol/g protein. The fluorescence content showed a decreasing trend with the increase of oxidation time and reached the lowest value at 12 h. Under the treatment conditions of 50 mmol/L H2O2， the free amino group content decreased significantly with the increase of oxidation time， and decreased to 65% of the control group content at 12 h. Electrophoretic analysis showed that under non-reducing conditions， the degree of protein aggregation increased with the prolongation of oxidation time， and the degree of protein aggregation decreased after the addition of β-mercaptoethanol. The microstructure indicated that as the oxidation time increased， the myofibrillar protein had a compact structure and the degree of hinge of the protein was higher. In summary， the structural changes of the sea cucumber myofibrillar protein caused by oxidation in the hydroxyl radical system. This research has certain theoretical significance for controlling the quality of participation in the sea cucumber.

Abstract:In this paper， zein-arabic gum （AG） nanoparticles loaded with tocopherol （TOC） were prepared by antisolvent method. The effects of different zein ∶ AG ratios and the stirring speeds on the stability of zein-AG nanoparticles were investigated， and the effects of different pH and the different concentrations of salt were also investigated. The experimental results showed that the nanoparticles with zein ∶ GA ratio of 1 ∶ 1.5 and the stirring speed of 200 r/min were stable， and the particle size was 125.4 nm， the polydispersity index （PDI） was 0.19 and the zeta-potential was -32.8 mV. When the pH=3~9， and the concentration of salt ion was less than 20 mmol/L， the zein-AG nanoparticles were stable which proved that zein and AG were bound effectively and had a certain charge shielding effect. The stability of zein-AG nanoparticles loaded with TOC was significantly improved， and the removal capacity of DPPH， ABTS and superoxide anions were higher than that of zein-AG nanoparticles. Moreover， zein/AG-TOC nanoparticles could achieve slow-release in gastrointestinal simulation experiments.

Abstract:Effect of pectin structure on the properties of pectin-β-casein complex systems was investigated in this study. Six types of pectin （L13， L101， L102， L104， H121 and H150） with different structures （galacturonic acid content GA， degree of methoxylation DM， degree of amidation DA， molecular weight Mw） were combined with β-casein， and methods including dynamic light scattering， zeta potential， fluorescence spectroscopy and circular dichroism were applied to determine particle size， zeta-potential， secondary structure， solubility， emulsifying and foaming ability of pectin-β-casein complex systems. Finally， multiple linear regression analysis was used to evaluate the contributions of various pectin structure to the properties of pectin-β-casein complex systems. The results showed that electrostatic interaction was occurred between pectin and β-casein resulting in forming complexes， and addition of pectin changed molecular structure of β-casein. Pectin-β-casein complexes have higher emulsifying ability and foaming ability than β-casein. Multiple linear regression revealed that solubility and emulsification were positively correlated with GA， DM and DA， but negatively correlated with Mw. DA had the greatest effect on solubility and emulsifying properties， and they were minimally affected by Mw. The foaming ability was positively correlated with GA and DM， but negatively correlated with DA and Mw. DA has the greatest impact on foaming ability， and Mw has the least impact on it.

Abstract:The purpose of this paper was to investigate the fatty acid release characteristics of OPO structural lipids in simulating the gastrointestinal digestive environment of infants. According to the characteristics of fatty acid composition of breast milk， OPO structural lipids （O Group） were prepared in this study， and mixed vegetable oil （Z group） in infant formula was used for comparison. The fatty acid composition and the distribution of fatty acids at the Sn-2 position were measured. The changes in fatty acid release rate， particle size and zeta potential during digestion were analyzed， and the composition of free fatty acids and monoglycerides in the digested products was determined. The results showed that under the same treatment conditions， the particle size of the O group was concentrated at 198 nm， and the Z group was mostly distributed at 229 nm. The difference in particle size distribution reflected the significant difference in fatty acid release rate during the initial digestion stage （P<0.05）. After 30 min of the simulated gastric fluid， the fatty acid release rate of the O group was 12.83%， and the Z group was 8.92%. After the in vitro gastrointestinal digestion， the final release rate of fatty acids in O group was 62.67%， while the final release rate of fatty acids in Z group was only 51.83%. The analysis concluded that there was a difference in the distribution of Sn-2 fatty acids in the O group and Z group （P<0.05）. Thin-layer chromatography confirmed that the content of Sn-2 palmitic acid in the O group was higher and closer to that of breast milk， and showed higher fatty acid release rate when simulated in vitro digestion. After methylation of the digested product， GC-MS analysis showed that the content of free unsaturated fatty acid and palmitic acid monoglyceride in the O group was higher than that in the Z group. Therefore， comparing the digestion of OPO oils and mixed vegetable oils in vitro， it lays a theoretical foundation for the development of formulas that are more conducive to digestion and absorption of infants.

Abstract:Soy hull polysaccharide was extracted by microwave-assisted extractant method， and the effect of soy hull polysaccharide on the rheological properties of simulated intestinal fluid and its regulation on the intestinal flora were investigated. The basic components of soy hull polysaccharide （MOSP） extracted by oxalic acid and soy hull polysaccharide （MCSP） extracted by citric acid were detected. The OD value， pH value and rheological indicator of simulated intestinal fluid were detected after MOSP and MCSP were added to the medium for fermentation. The dynamic changes of intestinal flora were analyzed through Illumina-miseq high-throughput sequencing technology. The results showed that the yield of MOSP was 10.2% and that of MCSP was 5.9%. The purity， moisture and fat content of MOSP were higher than MCSP. The effects of MOSP on promoting intestinal flora proliferation and acid production within 0-24 h was better than that of MCSP. The apparent viscosity of MOSP was the highest at fermentation 24 h. The high-throughput sequencing results showed that both MOSP and MCSP could increase the content of bacteroidetes and firmicutes， and MOSP had a more obvious effect than MCSP. Both soy hull polysaccharides could change the rheological properties and improve the diversity and structural characteristics of the intestinal flora in vitro intestinal simulation system， and the MOSP could achieve better results.

Abstract:This article was aimed to study the effect of soluble dietary fiber in sweet potato residue on intestinal flora by vitro fermentation. Soluble dietary fiber was extracted from sweet potato residue by using enzyme hydrolysis. Then it was used as the main carbon source of vitro cultivation of intestinal flora and to observe the pH change， gas production rate， the content of NH3-N of the fermentation liquor after 0， 6， 12 and 24 h. Short chain fatty acids （SCFA） of the fermented liquid at 12， 24， 48 h were analyzed respectively. The effects of soluble dietary fiber on intestinal flora was determined through the changes of the above indicators. Compared with the control group， results showed that the experiment group added soluble dietary fiber could significantly reduce（P＜0.05） the pH of fermentation liquid， decrease the content of NH3-N in fermentation liquid， and significantly increase（P＜0.05） the output of SCFA which proved that soluble dietary fiber in sweet potato residues could improve the metabolites of intestinal flora and contribute to human intestinal health.

Abstract:Objective： The structure-activity relationship of longan polysaccharides and oat polysaccharides was preliminarily analyzed to provide scientific basis for the development of healthy food using longan and oat as raw materials. Method： Longan polysaccharides and oat polysaccharides were obtained from dried longan and oat bran by hot water extraction and deproteinization. The viable bacteria number and pH value were determined by adding two kinds of polysaccharides as carbon source and carbon-free MRS medium respectively， and the difference of beneficial effect was compared. Content and protein content were determined by gel permeation chromatography （GPC）. The monosaccharide composition was determined by GC/MS area normalization method. Amino acid composition was determined by HPLC-FLD method. The apparent morphology was observed by scanning electron microscope， rheology was measured by rheometer， and the structural basis of two kinds of polysaccharides were analyzed. Result： LP and OP as the sole carbon source could promote the proliferation of Lactobacillus casei， Lactobacillus acidophilus， Lactobacillus plantarum subsp. plantarum and Streptococcus faecalis， but proliferative effect of LP and OP were different. LP had a significantly better proliferative effect on Lactobacillus casei and Lactobacillus acidophilus subspecies than inulin（P<0.05）. The proliferative effect on Lactobacillus plantarum and Enterococcus faecalis was similar to inulin. OP had similar proliferative effect on Lactobacillus casei， Lactobacillus plantarum subspecies and Enterococcus faecalis. The effect was slightly higher than that of the blank group. The total sugar content of polysaccharide and oat polysaccharide was 61.2% and 68.3% respectively. The content of uronic acid was 10.1% and 5.9%， the content of reducing sugar was 16%， 5.4%， protein content was 2.2% and 2.9%. The average molecular weights（Mw） of LP and OP were 6.38×106 u， 5.42×103 u and 2.45×106 u， respectively. Longan polysaccharides consist of glucose， mannose， arabinose and so on. Oat polysaccharides mainly consist of glucose. The total amount and composition of hydrolyzed amino acids of the two polysaccharides are not significantly different. Scanning electron microscopy showed that the two kinds of polysaccharides were irregular sheets， the longan polysaccharides were smooth and tightly arranged， and the oat polysaccharides were rough and loosely arranged. In addition， the viscosity of the two kinds of polysaccharides solution was mass fraction-dependent， the viscosity decreases with the increase of temperature， and the viscosity of oat polysaccharides solution is more sensitive to temperature change. Conclusion： Longan polysaccharide had obvious proliferative effect on probiotics because of its complex monosaccharide composition， complex polysaccharide composition and low viscosity.

Abstract:The gene sequence of acetylcholinesterase was optimized based on codon versatility and the principle of difference codon usage frequency of different species， aiming to increase its expression in Pichia pastoris and enhance its application prospects. The low frequency codons in the gene sequence were replaced with Pichia pastoris preferred codons， while the GC content of each segment of the acetylcholinesterase was adjusted to 45%-55%. The optimized gene was ligated into the expression vector pPIC9K and transferred into Pichia pastoris GS115， and cultured in shake flasks. The enzymatic properties of the recombinant enzyme mdAchE were determined by the modified Ellman method， and the bioactivity of the recombinant enzyme mdAchE was analyzed by organophosphorus and carbamate pesticide inhibition assays. The mdAch E codon was optimized to achieve high expression in Pichia pastoris with an enzyme activity of approximately 8.82 U/mL. The inhibition test showed that the acetylcholinesterase could be inhibited by seven organophosphorus pesticides such as malathion and eight carbamate pesticides such as carbofuran. The minimum inhibitory concentration IC15 value was 1.83×10-15 μg/mL， which was far lower than the lowest detection limit （0.01 μg/mL， 4.14×10-6 μg/mL） measured by other methods such as gas chromatography， biosensors. The recombinant enzyme mdAchE has great application prospects in the detection of organophosphorus and carbamate pesticide residues.

Abstract:In order to explore the effect of different initial culture pH on the anti-freeze-drying activity of Lactobacillus plantarum LIP-1， the optimized medium was used as the basis， and the optimum pH was screened by single factor experiment. The groups with higher growth but significant difference in survival rate of LIP - 1 after freeze-drying were chosen to extracte the fatty acid composition of cell membrane and determine the enzyme activity of key cells. The results showed that there was no significant difference in the number of viable cells in the initial pH 6.8 and pH 7.4， which were 9.79 lg（CFU/mL） and 9.70 lg（CFU/mL）； however， the freeze-drying survival rate was significantly different （P<0.05）. They were 81.76% and 72.43% respectively. Further analysis showed that suitable initial pH culture can promote the synthesis of unsaturated fatty acids in cell membranes and ensure better enzyme activity， improve cell membrane fluidity， maintain cell integrity， reduce lyophilization of strains and enhance antifreeze drying of strains. Based on this， this study provides an important scientific basis for the study of lactic acid bacteria resistance to freeze-drying， and lays a theoretical foundation for promoting the industrial production of probiotics in China.

Abstract:The antagonism effect of Lactobacillus plantarum DL3 isolated from traditional northeast suan-tsai against Shewanella putrefaciens was studied. Through the analysis of the minimum inhibitory concentration （MIC）， growth curve， cell membrane permeability， ultraviolet absorption material， protein synthesis and other indicators of S. putrefaciens， the antibacterial effects of lactic acid bacteria（LAB） against Gram-negative bacteria were preliminarily investigated. The results showed that the MIC of strain DL3 cell free supernatant （CFS） against S. putrefaciens was 8.0 mg/mL. L. plantarum DL3 CFS was added after S. putrefaciens culturing for 6 h， the steady-state cell growth of the growth curve of test bacteria was only one-half of the control group， and the number of cells decreased by 1.16 lg （CFU/mL）. The conductivity of S. putrefaciens with L. plantarum DL3 CFS was 34.3 ms/cm， and that of the control group was 33.1 ms/cm， and the OD260nm value of the experimental group was 11.95% higher than that of the control group， indicating that the intracellular nucleic acid substance released. SDS-PAGE confirmed that the number of protein bands in S. putrefaciens treated with Lactobacillus plantarum was small and the color was light. Scanning electron microscopy revealed that the cell wall of the S. putrefaciens cells was destroyed and the cytoplasm leaked. L. plantarum DL3 affected the permeability of the cell membrane of the test bacteria， destroyed the integrity of cells， caused leakage of intracellular nucleic acids， and affected the synthesis of bacterial proteins， led to leakage of proteins， caused cell death of S. putrefaciens.

Abstract:In order to study the effect of sulfhydryl groups（SH） and disulphide bonds （SS） on the rheological properties of dough， gluten samples， first treated with sodium sulfite of different concentrations， were added into flour to get flour samples with different SH and SS contents. The kneading and tensile properties of dough were investigated and the correlation between the parameters was also analyzed. The results showed that， as the content of SS bonds decreased obviously， there were marked drops in water absorption rate， farinograph quality number， time of dough formation and dough steadiness of mixed flour dough samples. There were significant differences among various samples （P<0.05）. As to extensibility， it was found that the sample B owned the best tensile property. The tensile properties of other samples in turn became poor with the increasing of Na2SO3 concentration added into gluten protein. The maximum tensile resistance and ductility of sample H were the worst but were still better than the control group. Based on the Pearson correlation analysis， there was obvious relationship between SS bonds content of flour samples and farinograph and tensile parameters. SS bonds was correlated strongly with water absorption rate， farinograph quality number， time of dough formation and dough steadiness， and the maximum tensile resistance， respectively. It had a negative correlation with the weakening grade. Additionally， it was correlated positively with ductility and stretch curve area. Hence， the above indices were effected strongly by SS bonds rather than free SH or the ratio of free SH/SS. To sum up， this study can provide theoretical basis for revealing the effects of gluten on processing properties of wheat flour and noodle and breeding specific wheat varieties.

Abstract:Objective： To determine whether mineral elements in water show positive effects on developmental behaviors， lipid metabolism and antioxidant capacity of the body when food can provide with adequate nutrition by use of juvenile zebrafish. 21 dpf （days after fertilization） juvenile zebrafish were randomly divided into four groups， fish water group （FWG， control group）， tap water group （TWG）， natural water group （NWG）， and purified water group （PWG）. Zebrafish were raised in corresponding water with the same feed， the number of deaths were recorded every day up to 90 dpf. After the zebrafish were put to death by anesthesia， body weight， body length and whole body mineral levels， TC， TG， HDL-C， LDL-C， MDA levels and SOD activity were measured， and the correlation were analysed. Results： Zebrafish in PWG showed significantly decreased calcium and zinc levels， survival rate， body weight and body length； zebrafish in NWG showed significantly increased HDL-C levels and significantly decreased TG， MDA levels； the correlation analysis showed that body length of zebrafish were significantly positively correlated with calcium and magnesium levels in water， TG levels were significantly negatively correlated with calcium， magnesium and zinc levels in water. Conclusion： Natural water， which has suitable pH， DO levels and proper amount of minerals together with reasonable Ca：Mg ratio， is the most suitable for body development， while purified water seems not suitable due to its lacking of calcium， magnesium.

Abstract:This study aims at evaluating the effects of Bifidobacterium Lactis BB-12 and Lactobacillus plantarum P-8 on the behaviors and gut microbiota in a depression model induced by chronic unpredictable mild stress （CUMS）. A depressed rat model was established by CUMS combined with separation. After 8 weeks， depressed model rats were treated with Bifidobacterium lactis BB-12 and Lactobacillus plantarum P-8 for six weeks by gavage. Additionally， healthy control group （HC） and model control group （CUMS） were given the same volume of sterile water. Behavioral tests were performed before and after gavage. After the end of the treatment， fecal samples were collected for 16S rRNA V4-V5 regions high-throughput sequencing. Results showed that two probiotics improved CUMS-induced depressed behaviors （including attenuated the decreased sucrose preference in the sucrose preference test and developed the activity and exploration of CUMS rat in the open field test， as well as in the light / dark test， pronounced decreased the time of CUMS rat spent in the dark zone） compared with CUMS group. Nonmetric Multidimensional Scaling （NMDS） revealed that probiotic supplement groups significantly modified the overall structure of the fecal bacterial community when compared to control groups （HC and CUMS）. Furthermore， two prebiotics also resulted in altering specific taxonomic compared with the control groups， including Bifidobacterium Lactis BB-12 decreased the levels of OTU556， OTU194 and OTU99 while Lactobacillus plantarum P-8 reversed the changes of OTU556， OTU194， OTU99 and OTU198. PICRUSt analysis revealed that a number of functions about intestinal microflora were disturbed by CUMS， and the two probiotics can only relieve dysfunction to a certain degree. Taken together， these results indicate an anti-depressant effect of Bifidobacterium Lactis BB-12 and Lactobacillus plantarum P-8 in rats subjected to CUMS and that this effect could be due to regulating the structure， composition and function of gut microflora.

Abstract:Diet is the most important and the most rapid environmental factor to reshape the structure and function of intestinal microflora. As a new yogurt that fermentated by Streptococcus thermophiles（S. thermophiles） with the cow maillard milk， burned yogurt， containing maillard reactive material without in conventional yogurt， may show a different changes on the intestinal microflora. A randomized open-label study was conducted to characterize the change of fecal microbiota in healthy adults （n=40）， who consumed burned yogurt twice （400 mL） daily for 4 weeks with no running-out （NS group） or 10 weeks with alternating elution and intervention （TS group）. Fecal samples were collected at different point， and samples were assessed for bacterial composition with 16S rRNA sequencing. It showed that burned yogurt consumption led to greater species richness（Chao 1， P=0.031） as compared to baseline， and a higher abundance of Streptococcus （adjustive P=0.009） between different time points. The intervention method of TS resulted in a higher difference in fecal microbiota composition compared to the NS （Chao 1， P=0.0045）， with greater abundance of Actinobacteria （predominantly Bifidobacterium， Pa<0.001）， and lower abundance of Bacteroidetes （predominantly Prevotella， Pa<0.001）. The above results suggested that browning yoghurt consumption could impact gut microbiota in healthy adults， and the longer consumption could help to maintain the abundance of beneficial genus， such as Bifidobacterium， Akkermansia， Streptococcus. However， our result was no agreement with the previous reports related to the butyrogenic microbiota of Veillonella， Roseburia， Faecalibacterium， Lachnospira， Coprococcus， Lactobacillus and the opportunistic pathogen， Bacteroides. The Nutrition and active components in burned yogurt is need to determined， and relationship and its mechanism to the change of intestinal microflora in health adults is also need to be further studied.

Abstract:Hypoglycemic mechanism of Lactobacillus plantarum 173 isolated from Shanxi aged Vinegar on type II diabetes rats was studied in this paper. Results showed that the strain of 173 improved the disorders in blood glucose， lipids， and hormones of diabetes rats. The fluorescence quantitative PCR results suggested that Lactobacillus plantarum 173 could regulate liver relative PPARs and GLUT4 mRNA expression， and improved the glucose homeostasis and insulin sensitivity. Moreover， Lactobacillus plantarum 173 promoted the growth of SCFA-producing bacteria. The antidiabetic effects of SCFA were closely associated with intestinal G-protein receptors GPR43 and GPR41. Furtherly， this study proved that the genes （ZO-1， Occludin， Claudin and MUC2） expression related to intestinal mucous membrane barrier were also involved in the beneficial effect of L. plantarum 173 on type II diabetes.

Abstract:Objective： To explore the alleviating physical fatigue effect of corn peptide in mice. Methods： The mice were divided into the control group（casein） and the low， medium and high dose group by their weight. Mice in three dose groups were orally given corn peptide samples for 30 d with various dose. The time of weight loaded swimming （WLS）， hepatic glycogen level， serum urea and blood lactic acid levels after swimming were observed sequentially. Results： Compared with control group， the result showed that the corn peptide could significantly improve the load swimming time in three dose groups （P＜0.05）. The hepatic glycogen contents in medium dose group had a significant increase （P＜0.05） as well as decrease remarkably in serum urea nitrogen contents after swimming（P＜0.05）， however the blood lactic acid level and AUC in three dose groups proved no statistical significance（P＞0.05） after swimming. Conclusion： Corn peptide has an effect on alleviating physical fatigue in mice with in a certain dose.

Abstract:Two kinds of two-dimensional axisymmetric models simulating the thermal sterilization process of pure water and 1.0% carboxymethylcellulose solution were established based on COMSOL Multiphysics software. The temperature changes simulated by different model at the same positions in the can were compared by wireless temperature sensor to verify the accuracy. The different performances of velocity field， temperature field and lethality field simulated by the two models were analyzed with 1.0% carboxymethylcellulose solution cans. The results showed that the model which considering the headspace could better characterize the physical field changes during liquid canned food sterilization. On this basis， the relative pressures in 1.0% carboxymethylcellulose cans at different headspace heights and different holding temperatures were analyzed by the model with the headspace. The higher the temperature was， the smaller the headspace height and the greater the relative pressure inside the cans became. Manufacturers could determine the pressure of different cans in each stage of the sterilization process to control the pressure of the sterilization tank and the maximum withstand pressure of the cans， so as to avoid the deformation of cans during sterilization.

Abstract:Objective： The objective of this work was to prepare， optimize and evaluate the soluble dietary fiber-fortified restructuring egg white curd from the salted egg white（main material） and resistant dextrin （nutrition fortifier）. Methods： The response surface methodology（RSM） was conducted to optimize the preparation with the degassing time， cooking time and resistant dextrin content as dependent variables， and the hardness （H）， total sensory score （TSS） and whiteness（W） as response variables. The texture analyzer， sensory evaluation， colorimeter and solid phase microextraction-gas chromatography-mass spectroscopy （SPME-GC-MS） were used for the quality evaluation. Results： The degassing time， cooking time and resistant dextrin content showed significant effects on the texture property， sensory quality and color of restructuring egg white curd. The optimum preparation was determined as a degassing time of 18.92 min， cooking time of 30.00 min and resistant dextrin addition of 5.89% （mass fraction）. The H， TSS and W of preparation-optimized soluble dietary fiber-fortified restructuring egg white curds were 1 853.37 g， 7.9 and 67.80， respectively. Besides， its volatile flavor component didn’t show significant difference compared with that of the restructuring egg white curd without the addition of resistant dextrin. Conclusion： The texture property and sensory quality of restructuring egg white curd were fortified by the soluble dietary fiber （5.89% resistant dextrin） without significant side effects on its appearance， color and volatile flavor characteristics.

Abstract:The microwave production process of Gannan navel orange whole fruit jam was studied by using the whole fruit of Gannan navel orange as raw material and microwave heating and concentration treatment without adding any thickener. The addition amount of the selected sugar， the microwave heating time and the microwave heating power were taken as the investigation factors， the sensory score was the response value， and the Bo-Behnken response surface method was used for the process development and optimization. The results showed that the addition of sugar was 35%， the microwave heating time was 260 s， and the microwave heating power was 770 W as the optimal process formula. The jam prepared under these conditions was bright yellow， spread evenly， moderately sweet and sour， and had a strong citrus aroma with a sensory score of 91.81. Compared with the commercially available jam， the microwave processing technology could better preserve the color and aroma components of the jam， and the taste， consistency and spreadability were all within an acceptable range.

Abstract:In this experiment， the peanut oil diglyceride was purified by molecular distillation technology， and the changes of glyceride composition， fatty acid composition， harmful substances and nutrients before and after synthesis and purification were studied. The results showed that the diglyceride with a purity of 85% and a yield of 18.54% could be obtained after secondary molecular distillation at 220 ℃. The fatty acid composition after molecular distillation did not change much， and saturated fatty acids increased. The content of trans fatty acids was low， only increasing from 0.75% to 1.2%. When the temperature exceeded 220 ℃， the content of glycidyl ester increases sharply， so the temperature of the secondary molecular distillation should not exceed 220 ℃. The physicochemical properties of peanut oil diglyceride meet the national standards. The nutrients will be reduced before and after molecular distillation， and a small amount of nutrients need to be added. This study provides theoretical support for plant technology of the purification of diglycerides by molecular distillation.

Abstract:Objective： the main purpose of this research was to study the effects of three emulsifiers， whey protein isolate （WPI）， sodium caseinate and octenyl succinic anhydride （OSA） modified starch on emulsion by pH-driven embedding of curcumin in O/W emulsion. Methods： the curcumin emulsions were prepared by pH-driven method with camellia oil as oil phase. The particle properties and encapsulation efficiency of three curcumin emulsions were investigated. The particle characteristics and appearance changes of curcumin emulsions with different pH were determined， and the bioacceptability and gastrointestinal stability of curcumin were determined by in vitro digestion experiment. Results： The OSA modified starch stabilized emulsion had a larger average particle size and entrapment efficiency， which were （327.8 ± 9.2） nm， （81.7 ± 1.5）%， and had good pH stability in the range of pH 4-7. There was no significant difference in gastrointestinal stability between the three curcumin emulsions， among which the bioaccessibility of OSA and WPI stabilized emulsions was higher， which was （43.4 ± 1.4）%， （47.1 ± 4.7）%， respectively. Conclusion： all three emulsifiers can stabilize the emulsion， and curcumin can be embedded in the emulsion by pH driving method， which provides a new idea for the design of bioactive material carrier.

Abstract:In recent years， wines are particularly popular with customers due to their special flavors and healthy benefits. As an important group of components in wines， phenolics make great contribution to the sensory quality and nutrition value. However， wines may go through repeated freezing and thawing during wine making， storage or transportation processes， due to the limitation of the current production， transportation conditions and research requirement. In the present research， High-Performance Liquid Chromatography/Triple-Quadrupole Tandem Mass Spectrometry （HPLC/QqQ-MS/MS） was applied to analyze the phenolics of wine samples （5 red wines and 3 white wines）， which underwent 0 to 5 freeze-thaw cycles， respectively. Results indicated that total anthocyanin content in wines reduced gradually with the increase of freeze-thaw cycles， and the degradation rate of acylated anthocyanins was slower than that of the non-acylated anthocyanins. But for other phenolics， freeze-thaw actions did not have a significant impact except the degradation of tannins to some monophenols was possibly promoted in a degree. Therefore， repeated freezing and thawing should be avoided or be reduced to assure the wine quality or the research reliability.

Abstract:In view of the current low level of R&D and production of synbiotics functional dairy products in China， most of them use the mixed fermentation of probiotics and traditional yoghurt bacteria. In this paper， with 18 newly probiotics isolated from natural fermented food， health products and microbial preparations and these strains contained in three commercial yoghurt starters used as test strains， the traditional yoghurt fermentation strains of Lactobacillus bulgaricus and Streptococcus thermophilus as control strains， by researching the curd time， acid producing ability and sensory quality of the fermented milk by these strains and analyzing the proliferative effect of these strains using stachyose， the probiotic which can utilize stachyose as a prebiotic to ferment the synbiotic yoghurt products was screened； the growth curve of the screened strain in pure cow’s milk basic medium was determined； the optimum addition amount of stachyose in the prebiotic proliferation medium was studied； the fermentation process conditions of yoghurt products with stachyose-probiotics sybiotics were optimized； the quality of 0 d and stored 21 d synbiotic yogurt product was tested. The results showed that the newly probiotic Lactobacillus casei 07-211 had the potential to ferment milk and can significantly proliferate with stachyose， and the number of viable cells increased from 3.19×108 CFU/mL to 2.05×109 CFU/mL. The optimum addition amount of stachyose in the prebiotic proliferation medium was 0.8%； the best process conditions for Lactobacillus casei 07-211 pure fermented stachyose synbiotic yoghurt were 3% inoculation， 4% sucrose addition and fermentation temperature at 42 ℃. The fermented synbiotic yoghurt products with the optimal conditions， whose curd time was at 4.15 h， pH was 4.65， titration acidity was 64.27 °T， the viable cell numbers was 3.96×109 CFU/mL， the sensory evaluation score was 8.78（10-point scale）， the quality of 0 d and stored 21 d synbiotic yoghurt exceeded the national standard. This study provided theoretical basis and technical support for the industrial production of Lactobacillus casei pure-fermented stachyose synbiotic yoghurt products， and also provided ideas and methods for the development and application of other functional synbiotics.

Abstract:To study the optimal conditions for enzymatic hydrolysis of mussel cooking liquor， this study researched the effects of flavor enzyme， trypsin， papain and complex protease on the hydrolysis of mussel cooking liquor with the degree of hydrolysis as an indicator. The results showed that the flavor protease was best for hydrolyzing mussel cooking liquor. Taking the degree of hydrolysis and flavor as indicators， response surface methodology and gas chromatography-mass spectrometry were used to optimize the conditions of the flavor protease hydrolysis mussel cooking liquor. The optimal enzymatic hydrolysis conditions for the mussel cooking liquor were as follows： enzyme addition amount 0.63%， hydrolysis temperature of 51 ℃， hydrolysis time of 3.26 h， hydrolysis pH 6.87， under these conditions the degree of hydrolysis was 13.98%.

Abstract:Changes in acid value， peroxide value， p-anisidine value， total oxidation value， tocopherol content and fatty acid composition under different baking conditions of butter were compared with those of lard and palm oil to determine the oxidative stability of butter. The results showed that butter has good oxidative stability under different baking conditions than lard and palm oil. With increasing temperature and time of baking， the acid value of lard and palm oil increased significantly （P<0.05）， and the acid value of butter also increased， and stabilized at 250 ℃ （1.69 mg/g）； Compared with lard and palm oil， the baking temperature and time had no significant effect on the peroxide value of butter （P<0.05）， which remained at 0.8-0.92 meq/kg； The maximum p-animide values of lard and palm oil （23.5 and 24.7） were higher than that of butter（22.8）. The total oxidation values of three baking oils were lard > palm oil > butter. When the temperature was 250 ℃， the tocopherol content of lard and palm oil was more loss （77%， 79%）， and the tocopherol content of butter was relatively less（72%）. The contents of polyunsaturated fatty acids in all three baking oils decreased， that of butter was the lowest at 180 ℃ （0.8%）， and no trans fatty acids was found. As the ratio of saturated fatty acids to unsaturated fatty acids increased， the oxidation stability of oils decreased.

Abstract:Sourdough is a mixture of flour and water， including microorganisms such as yeast， lactic acid bacteria （LAB） and mold. The pasta products fermented by sourdough have been deeply loved by people in recent years. In order to understand the basic characteristics of LAB isolated from traditional sourdough， a series of test methods were used in this paper， such as DNA extraction and construction of phylogenetic tree， microscope observation， infrared spectroscopic analysis， growth and growth curve determination， pH value and acid production curve determination， biochemical properties identifcation， antibacterial and drug susceptibility test. The identification results indicated that the LAB was Lactobacillus sanfranciscensis， a gram-positive bacteria， catalase was negative， and the bacteria was rod-shaped. Fourier transform infrared spectroscopy was used to analyze the cell components of bacteria including fatty acids， proteins， polysaccharides and other substances. The biomass of L. sanfranciscensis was （24 ± 1） g/L， the reproductive algebra was 0.36， the growth rate constant was 0.045， the generation time was 22.42 min， the lowest pH was 4.09 ± 0.01， and the total acidity was （0.70 ± 0.01） g/L. It can utilize maltose， and the degree of sucrose utilization has differences in bacterial species. It has inhibitory effects on Staphylococcus aureus， Escherichia coli and Candida albicans. And the 30 antibiotics tested have different effects on L. sanfranciscensis. A strain of high-yield exopolysaccharide LAB SXU-1001 was L. sanfranciscensis， which was the dominant LAB in traditional sourdough， and provided a reference for the development of LAB resources in sourdough.

Abstract:Objective： The aim of the study was to screen lactic acid bacteria（LAB） with high cholesterol-lowering ability and great probiotic properties， from fermented food and infant feces. Methods： 102 LAB strains were collected from 20 infant feces， 8 traditional fermented pickles and 4 Jinhua ham samples. The cholesterol-lowering ability of strain ZY08 and I631， tested by gas chromatography method， was significantly higher than that of standard strain （ATCC 43121） （P<0.05）， and were identified by 16S rDNA sequencing. The acid tolerance， bile salt tolerance， antibiotic sensitivity and antimicrobial activity of the two strains were evaluated. Results： Two probiotic strains with high cholesterol-lowering ability were screened： Lactobacillus plantarum ZY08 and Lactobacillus fermentans I631， and the cholesterol reduction rates were 67.45% and 63.19%， respectively. After incubation at pH 1.5 and 3.0 for 6 h， the viable bacteria numbers of strains ZY08 and I631 were greater than 6 lg （CFU/mL）； the two strains had a certain tolerance to 3， 5 and 10 g/L bile salt and the tolerance to bile salt was over 80% （3 g/L bile salt）； they were sensitive to the 8 kinds of antibiotics （penicillin， ampicillin， cefazolin， amikacin， gentamicin， erythromycin， sulfamethoxazole， chloramphenicol）， and had no potential threat to human health. The fermentation supernatant of these two strains had a certain inhibitory effect on four intestinal pathogenic bacteria （Staphylococcus aureus， Listeria monocytogenes， Escherichia coli O157∶H7， Salmonella typhimurium）. Conclusion： Lactobacillus plantarum ZY08 and Lactobacillus fermentans I631 with probiotic potential were obtained in this experiment， which could provide a source of strains for development and research of functional dairy products.

Abstract:The 28 strains of lactic acid bacteria was isolated from Mongolian dried beef. The antibacterial activity of 28 strains of lactic acid bacteria were detected by Escherichia coli， Staphylococcus aureus and Listeria monocytogenes as indicator bacteria. The strain 37X-3 and strain 37X-13 have strong bacteriostatic ability of the three kinds of indicator bacteria， and all the bacteriostatic activities are lost after pepsin and proteinase K treatment， indicating that the two lactic acid bacteria exert bacteriostasis by producing bacteriocins effect. The 37X-3 produced Pediococcus pentosaceus， 37X-13 produced Pediocin acidilactici by the identification of phenotype， physiological， biochemical and genetic type. The 2 pediocin could inhibit the growth of the three kinds of indicator bacteria at 121 ℃， 15 min and pH 2-6， and had the strongest antibacterical effect on Listeria monocytogenes. The 2 pediocin had a wide spectrum of inhibition，which could inhibit not only Gram-positive bacteria such as Bacillus subtilis and Enterococcus faecalis， but also Gram-negative bacteria such as Salmonella enterica and Shigella castellani.

Abstract:To clarify the influence of different stewed times on the sensory quality of mutton soup， 5 mutton soup samples prepared with different stewed times（DTS） were evaluated by sensory fuzzy integrate evaluating method （SFE） and value engineering evaluation（VEE）， and the volatile compounds were identified by gas chromatography-massspectrometry（GC-MS）. On this basis， partial least squares regression（PLSR） was established among volatile components， SFE and VEE scores to explore the contribution of volatile components to the sensory properties of DTSs in an intuitive form. Results showed that 58 volatiles were identified in DTS samples， of which could be classified into 4 value functional groups according to their flavor contribution， namely Z1 （terpenes and alcohols）， and Z2 （aldehydes）， Z3 （phenolic compounds and acids）， and Z4（ketones， esters and ethers）. Function index ranked in the order： DTS4 > DTS5 > DTS3 > DTS2 > DTS1， which was in accordance with the SEF results. Thus， 4 h was the best stewed time for preparing mutton soup. At the same time， PLSR indicated that functional components， such as 3-methyl-butyraldehyde， （E）-2-decenaldehyde， and carvacrol were significantly positively correlated with the SFE score， showing a positive effect on DTS flavor； while 4-methyl phenol and 4-methyloctanoic acid showed significantly negative correlation with SFE， thus reducing their content might improve SFE score of mutton soup.

Abstract:The fucoxanthin was used as raw material to investigate the antioxidant activity of fucoxanthin on fish oil and lard. The results showed that fucoxanthin could effectively inhibit the formation of malondialdehyde （MDA） in fish oil and pork in the oxidation model， and the highest inhibition rate was 78.1% and 80.9% compared with the blank group. The results showed that the electron spin resonance spectroscopy technique was used to investigate the scavenging effect of fucoxanthin on lipid free radicals in fish oil， corn oil， linoleic acid and linoleate models. When the fucoxanthin mass concentration reached 100 ng/mL and accelerated oxidation for 3 h， the inhibition rate of lipid free radicals in the fish oil model and the corn oil model was （64.46±6.46）% and （57.4±5.15）%； the fucoxanthin mass concentration was 300 ng/mL， and the accelerated inhibition of lipids in the linoleic acid model and the linoleate model was（75.24±7.32）% and （66.9±1.06）%. This study provides a theoretical basis for the application of fucoxanthin in the field of health foods and food antioxidants.

Abstract:The exploitation and utilization of turtle oil has a significant effect on the rational use of the by-product. In this study， referring to the drawbacks of traditional heating-assisted desorption in headspace solid phase microextraction-gas chromatography-mass spectrometry （HAD-HS-SPME-GC/MS） analysis of turtle oil volatile components， including long time heating， insufficient desorption， etc.， utilizing the benefits of laser technology in promoting the fast release of volatile components， a novel， fast， efficient and convenient laser-assisted desorption method was built， which was conducive to efficient release in a shorter period of time during the analysis of volatile components of turtle oil. The results showed that the experimental parameters were optimized， including laser power （10 W）， irradiation time （5 min）， sample addition amount （3 g）. A total of 53 volatile substances in the turtle oil were detected， and the main characteristic flavor compounds were nonanal， hexanal， heptanal， 2-nonanone， 2-undecone， 1-penten-3-ol， hexanol and so on. Compared with the conventional HAD-HS-SPME-GC/MS， the LID-HS-SPME could significantly reduce the extraction time to 5 min from a previous demand of 30 min， with similar fingerprint profiles and more volatile molecular species. Afterwards， the method was validated in terms of sensitivity， precision， and recovery， which indicated the LID-HS-SPME GC/MS method was efficient and remarkable. The results of this study had the reference value for rapid detection of volatile components in liquid samples.

Abstract:Baked cakes are open to fungal contamination. This study aimed to investigate the fungal diversity on baked cakes， to evaluate the feasibility of applying DNA barcoding to the identification of cake-contaminating fungi， and to analyze whether there are potential pathogenic species. Fungal cultures were recovered from four different flavors of cakes， and these fungal isolates were identified and analyzed based on the common fungal DNA barcode of nrDNA ITS sequences. Results： A total of 34 fungal cultures were attained from contaminated cakes. According to the ITS sequence similarity threshold of 97%， 9 different fungal species were identified， including Cladosporium， Neurospora， Penicillium， Aspergillus， Alternaria， and Zygosaccharomyces rouxii， mostly indoor air fungi. By searching the ISHAM database， the relatives of pathogenic strains were found for all these fungi. Most fungal genera are also known to include toxin-producing species. Although the number of fungal species isolated from each flavor of cakes is limited， the re-inoculating trial found that almost all isolated fungi could grow on a given flavor of cakes， and low temperature preservation could inhibit the growth of these fungi. Conclusion： This study provided the new understanding of the fungal diversity on baked cakes， and revealed that it was difficult to accurately identify cake-contaminating fungi by ITS sequences alone. Other alternate DNA barcodes were needed for accurate identification. Results of this study could also guide the reasonable preservation of cakes and ensure food safety.

Abstract:Based on proteomics theory， the method for the determination of adulterated donkey meat by liquid chromatography tandem mass spectrometry（LC-MS/MS） was established. In this study， data was acquired by high-resolution mass， and non-labeled quantitative analysis was carried out by proteomics software. The screened data by setting species-specific parameters was analyzed by principal component analysis （PCA） and the accuracy of the model was verified by experiments. Through further data screening， parameters setting and thermal stability investigation， three specific peptides of pig， donkey and horse were selected respectively and then transformed into specific ion pairs to establish LC-MS/MS method. The method could accurately measure the adulteration ratio of 0.5%. The results showed that the method is simple， accurate and reliable.

Abstract:To explore the action mechanisms of ginger for the treatment of COVID-19 using bioinformatics tools. Taking the three active ingredients of ginger （6-gingerol， 8-gingerol and 10-gingerol） as research objects， their potential target protein targets were predicted by chemical similarity measures. Meanwhile， viral pneumonia disease-related proteins were collected by manual data mining and constructed an interaction network via String 11.0. The core targets of ginger for the treatment of viral pneumonia were intersected and analyzed. The gene ontology（GO） enrichments and the KEGG pathway enrichments were performed via Omicshare and DAVID databases， respectively. Finally， the action mechanisms network of ginger was constructed using Cytoscape 3.3. The results showed that the three active compounds of ginger could act on 168 protein targets. And there had 253 viral pneumonia disease-related proteins. Then， the intersected 18 target proteins of ginger for viral pneumonia were obtained. The gene ontology （GO） of these core proteins involved inflammatory response， immune regulation， cytokine-mediated receptors and so on. And they participated 21 KEGG pathways， including virus infection， chemokine pathway and many cancer pathways. All results showed that the active compounds of ginger played pharmacological roles through multiple targets and multiple pathways. These findings provide an overview of the action mechanisms of ginger for COVID-19 treatment， and also basis of diet therapy.

Abstract:The human gut microbiota is closely related to the digestion and absorption of nutrients， immune regulation， as well as the occurrence and development of diseases. It has been considered as an important "organ" of the human body. Exploring dietary nutrition， mechanism of related diseases， intervention and prevention methods from the perspective of gut microbes have become main research focus. Mice， rat， zebrafish， fruit flies etc. are commonly used as model organisms in current research， but their gut microbiota show complex composition， poor stability and are difficult to operate. Honey bee gut possessed a simple yet specific gut microbiota， which showed similarities to that of human. It has been used as a good model for studying the function of gut microbiota. In addition， honey bee has a variety of related disease phenotypes， which can be used as a promising model to study the interaction between gut microbes and the host. This article summarized the characteristics of honey bee intestinal microbes. The advantages of honeybees as a model organism to study food nutrition， disease mechanisms and dietary interventions in the cases of obesity， diabetes， and neurodegenerative diseases were discussed. Methods for studying the microbiota has been introduced as a conceptual framework with honey bee as the model organism. This will provide a promising foundation to study gut microbiota， food nutrition， and health diseases.

Abstract:During the past ten years， Chinese leisure food industry has maintained an average annual growth rate of more than 10%. It is expected that the total output value of leisure food industry could reach about 3 trillion yuan in 2020 and 4 trillion yuan in 2025， with rapidly developmental rate and huge potential of development. However， there are still problems of leisure food industry， such as lack of clear concepts， clarification， statistical standard， and the development trend of technology industry remains obscure. This article analyzes the current status of the domestic and international leisure food industry， both from view of industry scale and technology， as well as the concept and clarification of leisure food， and provided the future development trend of technologic and industrial development of leisure food.