Abstract:Baijiu is Chinese national liquor with a long history. It is also a typical representative element of traditional culture and occupies an important position in the national economy. It meets people's needs for a better life not only from material， but also from the spirit. In view of this， the flavor and health benefits of Baijiu have always been the research focuses. This paper summarized the research methods， achievements and problems of Baijiu in two aspects of flavor and health efficacy in recent years， and put forward the future research directions. The aim was to provide a reference for the healthy development of Baijiu industry and even the whole liquor-making industry.

Abstract:Studies on the Difference about N6-Methyladenine Methylation of Lactococcus lactis subsp. lactis

Abstract:Vibrio parahaemolyticus is one of the important food-borne pathogens in coastal areas， and the problem of drug resistance of this bacterium is becoming more and more serious， it is urgent to develop safe， effective bacteriostatic agents with new action sites. In this paper， the effect of cell wall deletion on the biological characteristics of V. parahaemolyticus was studied with the cell wall as a potential target and cinnamyl alcohol as a bacteriostatic agent. The position and mode of the inhibition of cinnamyl alcohol on the bacteria were explored by measuring the changes in the minimal inhibitory concentration， growth curve， cell membrane integrity， inner membrane permeability and outer membrane protein competition test， and obtained dewalled cells were verified by drug sensitivity tests. The results showed that the cell wall deletion reduced the MIC of cinnamyl alcohol to V. parahaemolyticus to 1/8 of the untreated group. Cinnamyl alcohol has a strong inhibitory effect on V. parahaemolyticus in different states， which could cause cell membrane damage and cause intracellular characteristic macromolecular leakage. Colistin sulfate and wall removal could make cinnamyl alcohol lose its target. The outer membrane protein competition test further confirmed that cinnamyl alcohol could interact with outer membrane proteins. The de-walling treatment made the antibiotics that had been acting on the cell wall ineffective， indicating that the de-walling operation was done correctly. Conclusion： Cinnamyl alcohol can act on the cell membrane and outer membrane of V. parahaemolyticus， which may be targeted to the outer membrane protein. The outer membrane is the first barrier for small molecules to enter the Gram-negative bacteria and can be used as a new target for the development of bacteriostatic agents.

Abstract:Objective： To investigate the composition and content of terpenoids and sterols in the lipophilic extract of artichoke by-products， and to explore the protective effect of lipophilic extract on PC12 nerve cells induced by H2O2. Methods： Composition and content of terpenoids and sterols in artichoke byproducts were analyzed by GC-MS. Liposoluble extracts were used as protective drugs to protect PC12 cells injured by H2O2. Cell viability， LDH release， MDA production， ROS level and apoptosis rate were detected. Results： Three sesquiterpene lactones， two sterols and eight pentacyclic triterpenoids were detected in the by-products of artichoke. The content of cynaropicrin was the highest， up to 13 309.10 mg/kg DM. After being protected by lipophilic extract of artichoke byproducts， the cell viability of PC12 nerve cells increased significantly， the release rate of LDH， MDA content and ROS level in cells decreased significantly. After double staining by Annexin V-FITC/PI and AO-EB， the apoptosis rate of PC12 cells also showed a significant decreasing trend. Conclusion： Lipophilic extract of artichoke by-product has protective effect on PC12 nerve cells.

Abstract:In this paper， fucoidan SFP was obtained from Sargassum fusiforme by CaCl2 solution extraction. High performance liquid chromatography （HPLC）， high performance gel permeation chromatography （HPGPC） and chemical methods were used to determine the monosaccharide composition， molecular weight and physicochemical characteristics of fucoidan. Chitosan-fucoidan nanoparticles were prepared using a simple polyelectrolyte self-assembly method （the mass concentrations of fucoidan and chitosan were both 1 mg/mL） and the physicochemical characteristics as well as gastrointestinal stability of the nanoparticles were measured by in vitro simulated digestion. The results showed that the fucoidan from Sargassum fusiforme was mainly composed of mannose， glucosamine， glucuronic acid， galactose and fucose with the molar ratio of 3.96%， 0.37%， 0.42%， 27.20% and 68.05%. The average molecular weight of the fucoidan was about 101.5-701.0 ku. Besides， total sugar， protein and sulfate ester contents were detected and the results were 56.42%， 1.56% and 21.07%， respectively. Uronic acid was not detected using chemical method. The particle sizes of nanoparticles with different ratios of fucoidan/chitosan （Fuc/Cs=0.6 ∶ 1-1.4 ∶ 1） ranged from 330-450 nm and smallest at the ratio of 1.4 ∶ 1 while largest at the ratio of 0.6 ∶ 1. The Zeta potential ranged from 27 to 31 mV， while the PDI from 0.2 to 0.29 indicating that the nanoparticles were stable. The range of fucoidan loading rate was 85%-93%， which decreased with the increasing of Fuc/Cs ratio. Different ratios of nanoparticles showed good stability in the artificial gastric juice with little change in particle size， Zeta potential， PDI and fucoidan loading rate with the extension of time. In the artificial intestinal fluid， the particle sizes of nanoparticles significantly increased. The Zeta potential was all negative and the absolute value decreased while the PDI increased indicating that the nanoparticles swelled and depolymerized. When the ratios of Fuc/Cs were 0.6：1， 0.8 ∶ 1 and 1.4 ∶ 1， the fucoidan loading rate decreased significantly. At the ratio of 1.4 ∶ 1， the fucoidan loading rate decreased to 36%. In summary， Sargassum fusiforme fucoidan /chitosan nanoparticles showed good stability in artificial gastric juice and good depolymerization in artificial intestinal juice at the ratios of 0.6 ∶ 1， 0.8 ∶ 1 and 1.4 ∶ 1， which could be used as a potential delivery system for oral drugs.

Abstract:This study aimed to investigate the molecular interactions of silver carp myosin and three common plant polyphenols （EGCG， kaempferol， and quercetin） by protein homology modeling and molecular docking techniques. Moreover， the effects of EGCG binding to the myosin on entire structure of myofibrillar protein and its aggregation behavior were further explored， and the effect of tea polyphenol supplementation on microwave heating-induced gel formation of myofibrillar protein from silver carp was finally determined. The results showed that EGCG， kaempferol， and quercetin had the strong capacities to bind with myosin. Among them， EGCG had the greatest binding ability with the lowest docking energy， and the main interaction was noncovalent interaction including hydrogen bond and hydrophobic interaction. This interaction altered the secondary structure of myofibrillar protein， which reduced α-helix content， but increased β-turn and random coil contents， leading to a more unfolded structure of protein and its potential gel formation induced by high temperature. Furthermore， microwave heating contributed to the improved gel properties of myofibrillar protein as compared with water bath heating. Indeed， addition of 0.125-1 mg/mL EGCG could further improve the properties of microwave heating-induced myofibrillar protein gel. The beneficial effects of EGCG reached the maximum when the addition amount was 0.5 mg/mL， and the deformation and gel strength were increased by 59.9% and 89.8%， respectively. Therefore， the addition of EGCG and microwave heating could improve the gel properties of myofibrillar protein from sliver carp， and its mechanism was possible to be structure alteration and aggregation behavior of myofibrillar protein stimulated by interaction of EGCG with myosin. Our results may provide experimental and theoretical basis for improving the quality of surimi products of freshwater fish.

Abstract:The effects of hydrocolloids （guar gum， xanthan gum， gum arabic， pectin， konjac glucomanman， hydroxypropylmethylcellulose） on gelatinization and rheological properties of starch from Lilium bulbs were investigated through the determination of pasting， thermal， and rheological properties. The results showed that the gelatinization and rheological properties of the mixed system were significantly different. The peak viscosity， the trough viscosity， and the final viscosity of the guar gum mixed system were significantly increased， while other hydrocolloids mixed system were reduced. The peak temperature and conclusion temperature of the mixed system were reduced by adding hydroxypropylmethylcellulose with DSC measurement and the gelatinization temperature of the mixed system became higher after the addition of other hydrocolloids. However， the gelatinization temperature range and the thermal enthalpy value were reduced after the addition of the hydrocolloids. Lily starch with or without mixed hydrocolloids from different sources showed shear thinning phenomenon with the increased shearing frequency， all of which were pseudoplastic fluids. The elastic modulus （G′）， viscous modulus（G″）， and the consistency coefficient（K） of mixture were significantly increased by adding guar gum， whereas the fluid index （n） was decreased. The G′ and G″ of system mixed with other hydrocolloids showed different tendencies. These results could provide a reference for the application of lily starch and hydrocolloids mixed system in food.

Abstract:In this paper， the effects of 0-20 mg/mL pectin on polyphenoloxidase （PPO） enzymatic activity， thermal passivation kinetics， thermal passivation conformational changes and inhibitor action were investigated by ultraviolet spectrophotometer and fluorescence spectrophotometer， respectively. The results showed that PPO activity decreased with the increase of pectin mass concentration. When pectin mass concentration was 20 mg/mL， PPO activity decreased nearly 20%. The thermal passivation kinetics showed that pectin could significantly improve the thermal stability of PPO. Thermal treatment significantly changed the tertiary structure of PPO， while pectin could enhance the conformational stability of PPO under thermal passivation. The inhibitory effect of organic acids on PPO activity was increased by 1.5%-25.7% with the addition of pectin. The results of this study provide theoretical reference for the control of enzymatic browning of fruit and vegetable products.

Abstract:In this study， bamboo shoots were used as raw materials to prepare dietary fiber by cellulase hydrolysis. Then the basic physical properties， monosaccharide composition， structure properties and functional properties of the three dietary fibers were determined. The results showed that the soluble dietary fiber（SDF） had smaller particle size， uniform morphology， large specific surface area and good fluidity， while the total dietary fiber（TDF） and insoluble dietary fiber （IDF） showed irregular flaky structure， compact structure and poor fluidity. It could be seen from the monosaccharide composition that SDF was mainly composed of arabinose （24.64%） and galactose （38.05%）. TDF was mainly hydrolyzed to produce xylose （42.63%） and mannose （33.05%） and the content of xylose （41.77%） in the IDF hydrolyzate was the highest. All three dietary fibers had infrared characteristic absorption peaks of sugars. TDF and IDF have better crystallinity and thermal stability than SDF. SDF exhibited better hydration， cation exchange（0.56 mmol/g） and sodium cholate adsorption capacity （29.73 mg/g）， while TDF and IDF had stronger adsorption capacity for NO2- than SDF.

Abstract:Different mass concentrations of talcum （talc）， Al2O3 （alumina） and kaolin microparticles were comparatively conducted to examine the submerged fermentation performance of Aspergillus niger on the basis of the production performance of ferulic acid esterases. Derived from the experiment results， it was concluded that microparticles could improve the enzyme activity of ferulic acid esterases produced by A. niger. Among the tested microparticles， adding 0.5 g/L talc powder， alumina， kaolin， respectively， could lead to the highest specific activity of ferulic acid esterases. This research provides a new way to optimize and design the morphology of high-yield filamentous fungi， and at the same time has great value in improving the activity of ferulic acid esterase produced by A. niger ZJUQH.

Abstract:Objective： To investigate the effect of different processed foods on ACE activity， so as to provide data support for screening for foods with antihypertensive effect. Methods： The experiments of water extraction， pepsin hydrolysate and ethanol extraction of 15 kinds of drinks， 5 kinds of nuts and other 8 kinds of processed foods was carried out. The hippuric acid content was detected by high performance liquid chromatography （HPLC）， and their effects on angiotensin converting enzymes（ACE） activity in vitro were determined. Result： Most of ethanol extracts from 5 kinds of nuts and other processed foods promoted ACE activity， but most of their water extracts or pepsin hydrolysate inhibited ACE activity. The beverages containing milk had significant ACE inhibitory activity， while other beverages only weakly affected ACE activity. The pistachio water extract significantly promoted ACE activity. The pepsin hydrolysate of walnut and ham sausage significantly inhibited ACE activity， and the ACE activity was still significantly inhibited after the pepsin hydrolysate of walnut diluted 10 times. Some processed foods might affect blood pressure. In most foods， substances that raise and lower blood pressure may co-exist in the same food. Consumption of milk or walnuts may help to reduce high blood pressure.

Abstract:The effects of glycerol monolaurate （GML） on the glucose and lipid metabolism， systemic inflammatory response and the time-dependent influence on the gut microbiota in C57BL/6 mice were investigated. Results showed that GML neither affected lipid profiles and glycemic markers nor induced chronic systemic inflammation. However， GML promoted the growth of mice significantly and decreased the ratio of low-density lipoprotein-cholesterol and high-density lipoprotein-cholesterol at a trend level. High-throughput sequencing showed that GML reduced the Shannon and Simpson diversity index after 5-week and 17-week treatment. At the phylum level， GML changed the microbial compositions significantly after 5-week treatment， but had no such effect after 17-week treatment. At the genus level， the time-dependent effect on the microbiota within the control group （NCD） was greater than that on the GML-treated group （G1200）， thus the differential taxa between NCD and G1200 group at 5 weeks and 17 weeks were different. However， the promoting effect of GML on the beneficial taxa， such as Barnesiella， Oscillibacter and Clostridium XIVb， and inhibitory effect on the pathogenic Anaeroplasma precede the time-dependent effect， indicated that GML could not only maintain the stability of the microbiota， but also optimized the microbial structure. Furthermore， GML could efficiently stabilize the mucosal barrier by significantly increasing the mRNA levels of intestinal α-defensin and occludin， which were correlated with the beneficial taxa mediated by GML.

Abstract:To explore the effects of functional sugars on intestinal hormone secretion， matrigel were used to induce endocrine differentiation of NCI-H716 cells to establish an endocrine model. This model was used to evaluate the ability of trehalose， erythritol， sorbitol， xylitol， isomalt and L-arabinose to promote the secretion of glucagon-like peptide-1 （GLP-1）， glucagon-like peptide-2 （GLP-2）， and peptide YY（PYY）. The results showed that trehalose and sorbitol could significantly promote the secretion of GLP-1 and PYY， erythritol could significantly promote the secretion of GLP-1 and GLP-2， xylitol could significantly promote the secretion of PYY， isomaltitol and L-arabinose had no significant effect on the secretion of the three hormones. Trehalose， erythritol and sorbitol were selected to further study the mechanism of GLP-1 secretion. It was found that they could stimulate GLP-1 secretion by activating genes such as T1R2、T1R3、Gα-gustducin、PLCβ2、TRPM5 and increasing intracellular Ca2+ concentration.

Abstract:Objective： To study the anti-inflammatory effects of the stevia residue extract and its main components-isochlorogenic acids. Methods： Nitric oxide （NO）， prostaglandin E2 （PGE2）， superoxide dismutase （SOD） and malondialdehyde （MDA） were used to study the anti-inflammatory effects of the stevia residue extract and its main components-isochlorogenic acids both in vitro and in vivo by establishing LPS-induced RAW264.7 cell inflammation model and carrageenan-induced mouse paw edema model. Results： In vitro RAW264.7 cell inflammation model showed that the extract of stevia residue extract and its main components was ochlorogenic acids which could inhibit the production of NO in inflammatory cells. The anti-inflammatory effects were in the order： isochlorogenic acid C ≈ stevia sulphate extract > isochlorogenic acid A. The three samples had significant inhibitory effects on mouse paw edema. The inhibitory effects were in the order： isochlorogenic acid C > isochlorogenic acid A ≈ stevia residue extract. At high dose， the stevia residue extract and its main components-isochlorogenic acids， inhibited the production of NO in the liver of mice. Stevia residue extract and isochlorogenic acid C could significantly reduce serum NO and PGE2 levels in mice；and isochlorogenic acid A and isochlorogenic acid C could significantly increase SOD activity and reduce MDA content in mice， leading to reduced degree of body damage attacked by free radicals. All the three samples had no significant effect on PGE2 production in mice. In summary， the isochlorogenic acids in the stevia residue extract have a good anti-inflammatory effect.

Abstract:Objective： To explore the effect of undenatured type Ⅱ collogen （UCⅡ） on the motor function in aging db/db mice. Method： db/db mice fed all the life were randomly divided into model， UCⅡ intervention， and positive control groups， while， db/m mice and youth db/db mice were used as the normal control group and youth control group. After intervention for 12 weeks， crawl activity and catwalk index were estimated. And then 4 weeks later， the bone histomorphometry index as well as musculus gastrocnemius were measured. The results showed that the gastrocnemius muscle index in UCⅡ intervention group was 0.44%， which was significantly higher than that in the model control group（P < 0.05）， and the bone mineral density was 439.11 mg/cm3 in the UCⅡ intervention group mice， which was significantly higher than that in the model， normal and positive control groups（P < 0.05）， the trabecular bone volume and trabecular bone number in UCⅡ intervention group were significantly higher than that in the control and youth control groups （P < 0.05）. The crawl time in UC Ⅱ intervention group was longer than that in the model and positive control groups（P < 0.05）. Compared with the model control group， the stride， swing speed， speed， pace and regularity index in the UC Ⅱ intervention group were increased， while the swing phase and duty cycle decreased. Moreover， there was a positive correlation between the gastrocnemius index and the duty cycle， the crawling time（P < 0.05， coefficient > 0.5）， and a certain positive correlation between the bone mineral density and the crawling time， the duty cycle and the swinging speed （coefficient > 0.5）. Therefore， UC Ⅱ could increase gastrocnemius and bone density， improve motor function of aging db/db mice.

Abstract:The study investigated the in vitro fermentation of polysaccharide from Fagopyrum esculentum moench bee pollen（WFPP）， the effects of WFPP on the metabolites produced by human intestinal flora. By establishing an in vitro fermentation model， the pH value， total sugar content， NH3-N content and SCFAs content of fermentation broth were determined. The fermentation behavior of WFPP was analyzed to explore the beneficial effects of WFPP on human intestinal flora. The pH value and content of total sugar in the fecal culture declined as fermentation time increased， after 24 h of fermentation， the pH value of WFPP-H group decreased from 7.26 to 4.64， the percentage of the total carbohydrates consumed in WFPP groups reached up to 80%. The accumulation of NH3-N content was reduced significantly by adding WFPP in culture broth， and the higher the content of WFPP， the better the effect. Acetic， propionic and N-butyric acid were the dominant short-chain fatty acids （SCFAs）， which got a significantly rise in fermentation， the content of SCFAs in the culture broth of polysaccharide groups was WFPP-H>WFPP-M>WFPP-L. The results showed that WFPP could be hydrolyzed be human intestinal flora， which produced SCFAs lowered the pH value， reduced the accumulation of NH3-N， the WFPP have a potential prebiotic effect.

Abstract:The amino acid composition and molecular weight distribution of oyster whole powder and oyster peptide were analyzed. The effects of different concentrations of oyster powder and oyster peptide on the synthesis and secretion of testosterone， dihydrotestosterone and cyclic guanosine monophosphate（cGMP） in mouse leydig cells （TM3 cells） were studied to provide a basis for improving the sexual function of oyster peptides. The effects of oyster whole powder and oyster peptide on the survival rate of TM3 cells were determined by MTT colorimetric assay. The contents of testosterone， dihydrotestosterone and cGMP were detected by enzyme-linked immunosorbent assay. Nitrate reductase method was used to determine the content of nitric oxide （NO） and the activity of SOD in the cells was detected by nitroblue tetrazolium （NBT） chromogenic assay. The results showed that the oyster whole powder and oyster peptide had rich amino acid composition， the oyster peptide contained more essential amino acids and arginine， and the oyster peptide had a molecular weight of less than 1 000u as high as 92.1264%. Compared with oyster whole powder， oyster peptide could significantly promote the secretion of testosterone， dihydrotestosterone and cGMP in TM3 cells， significantly enhance the synthesis of NO in TM3 cells， and increase the SOD activity of TM3 cells， indicating that oyster peptides had promoting functions. The role of its mechanism may be related to the improvement of the NO-cGMP pathway by oyster peptides.

Abstract:Lactobacillus casei has been shown to possess cell envelope proteases， which play a major role in the degradation of proteins. In our study， the effects of Lactobacillus casei MM6 on reducing wheat proteinsantigenicity during food processing were investigated by three different processing methods： fermentation， dry heat （roasting） and moist heat （steaming）. Our results showed that Lactobacillus casei fermentation reduced the content of allergens Tri a 37， Tri a 18， Tri a 36 and Tri a 26 and decreased protein antigenicity. There was no significant difference between sponge fermentation （TF） and cold fermentation （CF） on reducing wheat protein antigenicity， but different from first fermentation （FF）. Steaming was different from fermentation and baking， which had a significant ability to reduce wheat protein sensitization. Steaming after fermentation with Lactobacillus casei MM6 could better alleviate the antigenicity of wheat proteins.

Abstract:The coix seed oil bilayer emulsion was prepared by chitosan oligosaccharide（CO） and whey protein isolate （WPI） which were cross-linked by glutamine transaminase. In vitro release of the bilayer emulsions was investigated using the simulative gastric and intestinal fluid. The results showed that both the bilayer emulsion using CO as an inner layer （mCO ∶ mWPI=1 ∶ 4） and WPI as an inner layer （mCO ∶ mWPI=1 ∶ 5） exhibited higher stability than that of the coix seed oil emulsion stabilized by WPI alone. In vitro release kinetics of both CO/WPI and WPI/CO bilayer emulsions fit well with Retger-peppas equation in the simulative intestinal fluid， of which the diffusion index was below 0.43， indicating that the release mechanism was due to the combination of Fickian diffusion and erosion control.

Abstract:The appropriate concentration of biogenic amines （BAs） in food are important in the regulation of several natural physiological processes， but the intake of large amounts of BAs can pose adverse physiological effects to the body. Entering of the large amounts of BAs formed in rice socking process into the fermentation along with socking rice may lead to an increase of BAs in Huangjiu. To control the accumulation of BAs in the rice soaking process， a strain of Lactobacillus plantarum 14-2-1 with high acid production and the ability of degradation of BAs was screened and inoculated in the initial stage of the rice soaking based on the analysis of microbial community structure of rice soaking water. The rate of increase in acidity accelerated， and a microflora dominated by L. plantarum was formed in rice soaking water， and the relative abundance in which was increased from 0.95% to 79.52%. The content of BAs was reduced to 2.44 mg/L， that decreased by 93.84%. It greatly reduced the content of BAs of rice soaking water by the Lactobacillus artificial inoculated technology that designed according to the analysis of microbial community structure of rice socking water. This study provides a new idea and method for the control of the accumulation of BAs in huangjiu brewing.

Abstract:This paper measured the effect of high pressure processing on the structure and properties of lactoferrin （LF） in different buffer systems [（phosphate buffer （PBS）， Tris-HCl buffer （Tris-HCl）， citrate buffer （CBS）] by Zeta potential， free sulfhydryl content， ultraviolet spectrum， fluorescence spectrum， circular dichroism and protein solubility. The results showed that the resistance of LF to high pressure in the three buffers was as follows： CBS>Tris-HCl>PBS， that was， the tertiary structure and solubility of LF in PBS were most easily changed by high pressure. The adsorption of anions in the buffer solution caused the isoelectric point of LF to change. The surface Zeta potential of LF in PBS， CBS， and Tris-HCl was -3.86-20.07， -6.89-19.6 mV and 1.24-23.37 mV， respectively. Accordingly， the adsorption capacity of anions was CBS＞PBS＞Tris-HCl. 600 MPa treatment in Tris-HCl at pH 7 caused a large amount of precipitation of LF， where the free sulfhydryl content reached the highest， 6.23 μmol/（L·g）， and the protein solubility was the lowest， 45.28 μg/mL. At pH 3， the α-helix content of LF was significantly lower than other samples， and the content of random coils was significantly higher than other samples， indicating that the secondary structure of LF was relaxed under acidic condition and was more susceptible to high pressure.

Abstract:To study the influence of smoking technology on the belly and back characteristics of sturgeon， hydrophilic interaction chromatography and mass spectrometry （HILIC-MS） was used to analyze the phospholipid composition of sturgeon meat， and principal component analysis （PCA） was used to study the difference of phospholipid composition. It was found that smoked sturgeon meat had a higher hardness， cohesiveness， springiness， gumminess and chewiness， but could cause the content of polyunsaturated fatty acid decreased. 20 kinds of PC molecules， 24 kinds of PE molecules and 12 kinds of PS molecules were detected in the sturgeon meat by lipidomics analysis. Through principal component analysis， it was found that phospholipids could be used as markers to distinguish the belly and back of sturgeon. After smoking， the difference in the composition of phospholipids in the back and abdomen of sturgeon meat decreased. The hot smoking technology is not suitable for the belly of sturgeon due to the high content of unsaturated fatty acids and liquid fumigation and other cold fumigation techniques should be considered for instead.

Abstract:In order to improve the safety and quality of fermented sausages， especially to inhibit the formation of nitrosamines in meat products， this study used compound fermentation agent and spices to make fermented mutton sausages， which were divided into control group， starter group， Allium mongolicum Regel + cumin group and Allium mongolicum Regel + cumin + starter group. 2% was used to inoculate the starter and add spices to the sausage filling. The samples of each stage were sampled to determine the changes of pH， aw， nitrite， 8 kinds of biogenic amines and 7 kinds of nitrosamines. The results showed that the combination of compound starter and spices had the best effect， after fermentation （2 d）， the nitrite residue （4.86 mg/kg） in the product was significantly reduced， and the content of NDMA， NDEA， NMOR and NPIP （P<0.05） and the accumulation of biogenic amines （tryptamine， phenylethylamine， putrescine， cadaverine， histamine and tyramine） （P<0.05）， and the NDMA content （1.605 μg/kg） met the national standard. At the same time， it could promote the decrease of pH and water activity of fermented sausage， reduce the growth of nitrite content （P<0.05）， improve the quality of product.

Abstract:The inhibitory effects of histidine， leucine， valine and methionine（0.1%， 0.5%， 1%） on the profiles of free heterocyclic amines（HAs） in roast beef patties were analyzed by ultra-performance liquid chromatography-tandem mass spectrometry. The results showed that the total free heterocyclic amine content in the control group was 28.49 ng/g， four amino acids could inhibit the increase of total heterocyclic amine content to some extent， the highest inhibition rate reached 43.84% （1% histidine）. Proline， leucine and methionine could significantly inhibit the generation of norharman and harman， with the highest inhibition rates of 100.00% （1% methionine） and 60.59% （1% histidine）， respectively， and histidine inhibited the generation of norharman and harman in a dose-depend manner. Proline could significantly inhibit the production of MeIQx with a maximum inhibition rate of 57.94% （1% proline） and also showed dose-depend manner. The results could shed light on the inhibition of production of heterocyclic amines in roast beef patties by amino acids.

Abstract:Stachys sieboldii Miq is a kind of food rich in oligosaccharide probiotics， which is often used as the raw material to make kimchi food. However， the traditional fermenting process has many problems such as high content of nitrite and serious contamination of harmful bacteria. In this study， high quality lactic acid bacteria with antibacterial activity， ability to reduce nitrite and to product B group vitamin was screened out based on the bacteria stored in laboratory. Among them， Lactobacillus plantarum ZJ316， Lactobacillus sakei ZFM225 and Lactobacillus paracasei ZFM54 showed strong antibacterial activity and nitrite degrading ability. These three strains all grew well in the medium of Stachys sieboldii Miq juice， and the growth of L. plantarum ZJ316 was the best， with OD600nm up to 1.84 after 24 hours of culturing. After 48 hours of fermentation， the nitrite degradation rate was 82.83% and the production of folate was up to 1.25 μg/100 mL. And it was found that the supernatant could inhibit the growth of most harmful bacteria， and had a significant inhibitory effect on food-borne pathogens such as Staphylococcus aureus. GC-MS analysis showed that L. plantarum ZJ316 could produce acids， alcohols， ketones and other flavor substances during the fermentation of Stachys sieboldii Miq juice， giving it excellent fermenting flavor. L. plantarum ZJ316 has good probiotics and fermenting characteristics， which is expected to be used in the development of green， nutritious and healthy kimchi products.

Abstract:In order to separate and purify the batyl alcohol products， the unsaponifiable matter in shark liver oil was used as the raw material， and the purity of batyl alcohol was used as the evaluation index， and the process parameters of the batyl alcohol product were optimized by the response surface method to optimize the neutral alumina column chromatography. The purity and composition were qualitatively and quantitatively analyzed by thin layer chromatography （TLC） and gas chromatography （GC）. The results showed that the optimum conditions were as follows： the volume ratio of eluent （dichloromethane： anhydrous methanol） was 9 ∶ 1， the loading amount was 3 g， the column loading was 0.012 g/g alumina， and the elution flow rate was 2 mL/min， the obtained batyl alcohol product purity was 18.23%， and the yield was 38.70%. According to the comprehensive analysis of TLC and GC， the batyl alcohol product mainly contains two kinds of active substances， batyl alcohol and squalene. Neutral alumina column chromatography enriches batyl alcohol and causes loss of squalene content in unsaponifiable matter. According to the standard curve of squalene， the purity of squalene was reduced from 54.21% to 49.18%. Finally， the precision and precision of the GC proved that the GC has good stability and precision. This study provides a theoretical basis for the industrial preparation of high-purity batyl alcohol products.

Abstract:In this paper， two strains of Aspergillus oryzae （A. oryzae） with different enzyme profiles were selected for soy sauce fermentation. This study aimed to preliminarily explored the relationship between the enzyme profiles and the quality of soy sauce by morphological analysis， physicochemical indexes analysis and sensory evaluation. SWJS-AO-K had higher enzyme activities of protein degradation， i.e. the activities of neutral protease， acidic protease and aminopeptidase in SWJS-AO-K koji were 2.2， 2.6 and 4.4 times of those in SWJS-AO-D koji. SWJS-AO-D had the higher activities of carbohydrate hydrolysis， i.e. the activities of saccharification and cellulase was 1.8 and 1.3 times of them in other strain. The enzyme profiles were closely related to the physicochemical indexes and sensory characteristics of soy sauce. Higher contents of total nitrogen， Maillard reaction， and total bitter amino acid were detected in soy sauce fermented by SWJS-AO-K， the strain with higher enzyme activities of protein degradation. While higher contents of reducing sugar， total umami amino acids and total sweet amino acids were observed in soy sauce fermented by SWJS-AO-D， which had higher enzyme activities of carbohydrates hydrolysis. Compared with those contents in SWJS-AO-K soy sauce， the contents increased 80.80%， 5.14% and 4.10%， respectively. The results agreed with the sensory evaluation， i.e. SWJS-AO-D soy sauce has higher intensities of umami and sweet than those of SWJS-AO-K soy sauce. The results showed that the enzyme of carbohydrate hydrolysis had positive effects on the production of umami and sweet compounds in fermented soy sauce. This study will provide important theoretical guidance for the screening and breeding of Aspergillus oryzae.

Abstract:GC-MS， sensory analysis， total acid content， amino acid nitrogen content， texture and ethyl carbamate （EC） content were used as evaluation indexes to evaluate the quality of egg fermented bean curd produced by Mucor wutongqiao， Mucor wutongqiao and Saccharomyces rouxii mixed fermentation， Micrococcus luteus， Micrococcus luteus and Saccharomyces rouxii mixed fermentation， Rhizopus oryzae， Rhizopus oryzae and Saccharomyces rouxii mixed fermentation at different stages. As the results， GC-MS analysis showed that there were significant differences in the flavor substances produced by the six groups of bacteria. The content of ester compounds in Rhizopus oryzae， Rhizopus oryzae and Saccharomyces rouxii egg fermented bean curd was over 90%， which was significantly higher than that of other four kinds of egg fermented bean curd， while， the pleasant volatile flavor such as phenylacetaldehyde， nonaldehyde， ethyl tetradecanoate， ethyl octanoate， diethyl succinate and anetholecontent were significantly lower than those of the other four kinds of egg fermented bean curd. Sensory evaluation screened out that the flavor of egg fermented bean curd produced by Mucor wutongqiao， Mucor wutongqiao and Saccharomyces rouxii mixed fermentation was better. The results of amino nitrogen detection showed that the content of amino nitrogen in Mucor wutongqiao egg fermented bean curd was higher and the quality was better. So， Mucor wutongqiao was the most suitable strain for egg fermented fermented bean curd. Among the six groups， Micrococcus luteus and Saccharomyces rouxii egg fermented bean curd had the highest EC production （111.6 ng/g） at 63 days， which was far below the international standard established by FAO.

Abstract:In this study， the optimal extraction process of hempseed protein isolated （HPI） was obtained by the response surface method. On this basis， the composition and emulsifying properties of the HPI were studied. The results showed that the optimum extraction parameters of HPI was as following： ratio of solid to liquid was 1 ∶ 20， duration time was 70 min， duration temperature was 44 ℃， duration pH was 8.3 and the protein extraction rate was（39.15±0.28）%， with a protein content of 93.54%. Hempseed protein consists mainly of globulin（edestin） and albumin. By SDS-PAGE， The protein subunits of HPI were distributed in the range of 20-50 ku. The globulin and albumin accounts for 76.41% and 23.59% of HPI. Hempseed globulin was composed of acidic subunits and basic subunits with molecular weights of 37 ku and 21 ku， respectively. The solubility and emulsification of HPI were influenced by pH， heated-temperature and duration time. The emulsifying activity tended to decrease and then increase range from pH 2-10. But with the increase of temperature and the extension of heating time， emulsifying activity tended to increase and then decrease. The emulsification was 305.53 m2/g and the emulsification stability reached 92.04% at pH 10， 55 ℃ and heated for 60 min. The emulsion of HPI was examined by micrograph which had small particle size and uniform distribution contributing to better emulsifying stability. This study provides theoretical support for the emulsification application of HPI.

Abstract:A post-fermentation process of Pixian broad-bean paste was conducted at a constant temperature in a semi-closed system while the traditional natural process was carried out. Based on the analysis of the processes， the kinetic models of describing parameter variations were proposed. The variations of total acid， amino acid nitrogen， reducing sugar and chromaticity for the two processes could be simulated from the exponential model， Logistic model， GaussAmp model and linear model， respectively. The variations of moisture and free amino acids for natural fermentation could be simulated from the exponential model while those for constant temperature fermentation could be simulated from the linear model. The moisture， total acid and chromaticity could be kept better in the semi-closed fermentation system while the more contents of amino nitrogen， reducing sugar and free amino acids could be obtained by the traditional fermentation process. The results of the traditional fermentation provided a powerful reference for the fermentation in the semi-closed system by fitting and analyzing the kinetic models.

Abstract:In order to optimize the stewing parameters of soup obtained by yellow-feather broiler， a orthogonal test was used to evaluate the Gushi chicken soup with yield， color and flavor. The results showed that under the condition of certain cooking power and time， as the proportion of water increased， the production rate of chicken soup increased， the brightness value increased significantly， the redness value and the yellowness value decreased significantly. When the salt content was 0.35%， the ratio of flavor amino acids to total amino acid in the chicken soup， the ratio of inosinic acid and guanylic acid to the total taste nucleotides and the content of polyunsaturated fatty acids were the highest. Though the different of occasion of salt added time did affect the taste and aroma precursor content， it had no effect on the overall acceptance of chicken soup. The optimum processing parameters during 1.5 hours stewing period was as follows： the rate of chicken meat and water was 1∶1.5， the salt content was 0.35% of the total weight and the salt was added after cooking. This processing technology could ensure the dissolution of taste and aroma precursor material.

Abstract:Objectives： To study the effect of low heat treatment on furosine in milk under the conditions of different reactant mixing ratio， temperature and time. Methods： Through the analysis of LC-MS， HPLC and OPA methods， the contents of furosine， lactose and lysine were determined and the correlation between substrate ratio and furosine content and the influence of heating temperature and time on the loss rate of lysine and lactose and the formation of furosine were explored， so as to establish the corresponding control requirements of the processing. Results： When the mass ratio of lysine to lactose was 1 ∶ 10， the furosine content reached a maximum value of 1 104.96 μg/mL （72 ℃， 15 s） and 1 451.22 μg/mL （80 ℃， 15 s）， respectively. During the temperature range of 66-80 ℃， the total content of furosine increased with the increase of temperature. The growth rate of furosine and the decrease rate of substrate lactose and lysine were slow in the 10 s before reaction. Conclusions： The formation of furosine can be inhibited by controlling the ratio of substrate， heating temperature and reaction time.

Abstract:In this paper， label-free technique was applied to determine the proteomics of mulberry leaves drying by two drying methods. The results showed that 4 292 proteins were detected totally and 114 differential proteins were discovered by two drying methods. Total protein covers 11 molecular functions， including cell development（7%）， cytoplasmic （2%）， energy metabolism （10%）， cell membrane and substance transport （4%）， metabolic process （11%）， photosynthesis （13%）， protein folding， transport and degradation （2%）， protein synthesis （7%）， signal transduction （6%） and stress defense（8%）. Analysis of differential proteins showed that the retention rate of macromolecular protein in vacuum freeze-drying was higher than heat pump drying. The content of chloroplast protein and cell structure protein decreased significantly in heat pump drying treatment， and these proteins were survived in vacuum freeze-dried. Heat pump drying treatment may also lead to increased stress-related protein. The results revealed that different drying methods affect the protein content and composition of mulberry leaves， and vacuum freeze-dried might be more suitable for mulberry leaves dehydration.

Abstract:In the process of heat sterilization， there are problems in measuring the cold spot temperature and the sterilization intensity of the food， and the problem that the actual temperature of the sterilization retort deviates from the control temperature due to the instability of the heat source. This paper developed a device that could display the sterilization intensity of food centers in real time and thus intelligently corrected the control temperature. The device mainly included real-time F value calculation part and correction part， which was suitable for different types of sterilization retorts， and supportive PC software was developed. The experiment showed that the deviation of the food center temperature and the value calculated by the device according to the temperature of the sterilization retort was about 3.12%， and the deviation could be corrected according to the set sterilization value. The deviation between the sterilization value and the set value was 5.5%， which could meet the engineering application.

Abstract:Studies on Quality Deterioration and Organic Acid Metabolism of Red Pitaya during Storage

Abstract:A method for simultaneous detection of 28 mycotoxins in edible oil was established by ultra performance liquid chromatography-tandem mass spectrometry. Sample preparation was fulfilled through two-step liquid-liquid extraction and solid-phase extraction sequentially. The methodological verification results showed that the limits of quantification （S/N， 10） ranged from 0.07 μg/kg to 1.25 μg/kg， which were far less than the maximum levels of mycotoxins in foods. In addition， the recoveries of the three-level spiked samples were between 60% and 120%， and the relative standard deviations were less than 12.5%， which could meet the quality control specifications required in the national standard GB/T 27404-2008 Criterion on quality control of laboratories - Chemical testing of food. Using this method， risk monitoring of mycotoxins in the edible oils was executed， showing that aflatoxins， zearalenones and derivatives， sterigmatocysin and T-2 could possibly contaminated edible oils. In peanut oils， aflatoxins， zearalenone and sterigmatocysin were the main mycotoxins while zearalenone and its derivatives were the main mycotoxins in both rapeseed oils and corn oils.

Abstract:When the national standard GB 4789.10-2016 was used to isolate and identify Staphylococcus aureus from frozen meat and meat products， it was found that the interference of background flora was so serious to lead to a large number of false negative results. In order to solve this problem， the national standard method was modified as follows， 10% NaCl broth was used for pre-enrichment；then the suspicious S. aureus colonies on Baird-Parker agar plates were picked on tryptic soy agar plate containing 4% agar and 2% ethanol to be further purified， and the subsequent verification was carried out as the standard. Finally， the isolation rate of S. aureus was improved from 2.61% to 19.98%. This modified methord effectively reduce the occurrence of false negative results.

Abstract:Shanxi aged vinegar is traditional brewing food with Daqu as starter in solid-state fermentation， the microorganisms of Daqu is important during Shanxi aged vinegar fermentation process. The aim of this study was to analyze the bacterial community structure and bacterial abundancein Daqu of Shanxi aged vinegar. Total DNA was extracted from Daqu of Shanxi aged vinegar， bacterial community was analyzed by Miseq high-throughput sequencing platform and 16S rDNA gene sequencing. The bacteria in Daqu were rich， including Firmicutes， Proteobacteria， Actinobacteria and Bacteroidetes at phyla level. Firmicutes and Proteobacteria were dominant phylum， their abundance were 69.67% and 29.17%， the proportion of Actinobacteria and Bacteroidetes were 0.86% and 0.28%， respectively. Bacilli was detected only in Firmicutes， Lactobacillus （32.82%） and Bacillus （29.45%） accounted for the main majority of the Bacilli. Gammaproteobacteria was detected in Proteobacteria， mainly including Pantoea （27.36%） and Acinetobacter （0.80%）. Composition of Actinobacteria and Bacteroidetes were relatively simple， Actinobacteria and Flavobacteriia at class level， while Saccharopolyspora （0.59%） and Flavobacterium （0.27%） at genus level were found. These results clearly reflected the structure of bacterial community of Shanxi aged vinegar Daqu， and to help reveal the fermentation mechanism of Shanxi aged vinegar.

Abstract:In order to explore a comprehensive evaluation method of food safety matching to the big data of supervised sampling test data， a fuzzy mathematics model for safety assessment of pesticide residue pollution of agricultural products was established based on the principle of entropy weight. In accordance with the large scale of sampling test data of pesticide residues in fruits and vegetables collected continuously from August 2017 to July 2019， an efficient comprehensive evaluation model was constructed and the evaluation effect of fuzzy mathematics model was studied by comparing with the traditional single-factor analysis. The results indicated that the overall safety of agricultural products in the market was at the level Ⅰ（micro risk）. Among them， the comprehensive risk of pesticide residue pollution of agricultural products was mainly determined by dimethylimide and benzimidazole pesticide in leafy vegetables （level Ⅱ， low risk） and bulbous vegetables （level Ⅱ， low risk）. This result was valuable for developing the supervision and sampling. Compared with the traditional analytical method， not only the comprehensive fuzzy evaluation method with the normalized and uniform evaluation system could achieve consistent evaluation results， but demonstrate better evaluation effectiveness for big data analysis. As a result， it is considerably applicable for the food safety evaluation and benefit to improving the efficiency of food safety supervision.

Abstract:To further understand the drying dynamics of materials， a ‘technical platform for on-line determination of materials moisture content and state’ was designed and manufactured for on-line tracking and measuring the changes of moisture state， content and migration during drying process. The platform could be used to realize real-time， on-line and in-situ detection of moisture content， state and distribution of materials， thus obtaining time-dependent dynamic characteristics of moisture content， moisture binding state and proton density distribution. The test and analysis of typical drying process of Chinese dried noodles showed that the platform had good controllability， high stability and good repeatability. It could be used as an effective instrument for the drying kinetics exploration， new drying equipment manufacturing， and drying process design of various materials， including food products， agro-products， medicine， wood and volatile materials.

Abstract:The volatile flavor compounds and flavor characteristics of four groups （control group；fermentation group；scallions group；scallions + fermentation group） of fermented mutton jerky samples were analyzed using gas chromatography-mass spectrometry（GC-MS）， and combined with electronic nose and electronic tongue to distinguish the flavor of different additives fermented mutton jerky. The results showed that a total of 27 main volatile compounds were detected by GC-MS technology. The main acids were ovaleric acid and acetic acid， and the main esters were methyl oleate. The lauric aldehyde， hexanal， heptaldehyde and n-octanal were the main components of aldehydes， hexanal was not detected in the control group， hexanal， heptaldehyde and n-octanal were not detected in the scallions group. The main alcohols were phenylethyl alcohol， the control and fermentation group were not detected. The main hydrocarbons were o-isopropyltoluene， and the main ketones were3-hydroxy-2-butanone and 2，3-octanedione， scallions group were not detected 3-hydroxy-2-butanone and the starter group did not detect 2，3-octane. Through principal component analysis（PCA） and radar chromatogram analysis， GC-MS technology combined with electronic nose/electronic tongue could be used to effectively distinguish different additives fermented mutton jerky and identify the volatile components and characteristic flavor compounds of fermented mutton jerky successfully. The study provided a reference data for distinguish flavor of different fermented products.

Abstract:In this study， soluble solids content （SSC）， total acid （TA）， sugar-acid ratio and firmness of postharvest peach fruits were determined by near infrared spectroscopy. The effects of different spectral pretreatment methods on the models were discussed. Partial least squares （PLS） models of the physical-chemical properties of peach fruit were established and predicted. Before modeling， variance analysis and Pearson correlation analysis were used to study the relationship between several indexes and storage time. For SSC， TA， sugar-acid ratio and firmness， the correlation coefficient of calibration set （Rc） of SSC， TA， sugar-acid ratio and firmness optimal PLS model were 0.93， 0.69， 0.74 and 0.97， respectively， and correlation coefficients of the validation set （Rp） were 0.79， 0.69， 0.68 and 0.95， respectively. The root mean square error of cross validation （RMSECV） were 0.56， 0.11， 4.24 and 8.81， respectively. The root mean square error of prediction （RMSEP） were 0.89， 0.10， 6.02 and 16.22， respectively. The results showed that near infrared spectroscopy was feasible for the rapid detection of SSC and firmness of peach fruit， while the quantitative models of TA and sugar-acid ratio needed to be further optimized. This study provides a technical reference for the non-destructive determining and quality control of juicy peach during low-temperature storage in practical production.

Abstract:This paper introduced a cholesterol detection method based on hemin chloride mimetics enzyme catalyzed the production of fluorescence by tyramine peroxide. Fluorescence（with excitation/emission maxima at 320 and 426 nm） increased linearly in the 0.1 μmol/L to 2 μmol/L cholesterol concentration range at the optimum conditions. The correlation equation was F=34.85C+165.3 （R2=0.992）. The detection limit based on the 3σ/k criterion reached 0.08 μmol/L. The proposed assay was successfully employed for cholesterol detection in （spiked） several kinds of milk samples with recoveries of 98.7%-112.7%. Given its high sensitivity and good stability， this method has good specificity through selective decomposition of the substrate by cholesterol oxidase. Therefore， the method can be used to detect cholesterol in milk.

Abstract:To explore the influence of data processing methods on identification of rice from different geographical origins by Raman spectroscopy， this paper took Panjin rice， Xiangshui rice， Xijiang rice， Jiansanjiang rice， Wuchang rice and Yanbian rice as examples， the accuracy of identification model under different data processing methods were investigated. Rice samples were carefully finished， crushed and screened to collect rice flour with particle size of 100-140 mesh. Raman spectra are collected at five measuring points for each sample. Then， relative standard deviation analysis and hierarchical clustering analysis were used to eliminate the difference data. Finally， all the data before and after eliminating the difference data and the data before and after taking the average value are separately constructed for establishing classification model by support vector machine. The results showed that hierarchical cluster analysis could identify the potential difference data. Relative standard deviation analysis could preliminarily determine whether there were difference data and ultimately verified whether they were indeed the difference data. In addition， the data after taking the average value could narrow the difference in the same rice samples and expand the difference between different rice samples， which could effectively improve the recognition accuracy of the model. The data processing method explored in this paper， that was eliminating the difference data followed by taking the average value， could improve the recognition accuracy by 12.89%， provided a more accurate and effective data for identification of rice from different geographical origins.

Abstract:In order to accelerate the detection efficiency of natural pigments stability， a new type of versatile and multi-conditions controlled apparatus for real-time kinetics based on online spectrophotometry was developed and applied to fading kinetic parameter determination of mulberry pigment with initial kinetic method， the effects of temperature， light and oxidant on stability were investigated. Results suggested that the apparatus was simple and extensibility， accurate and stable， applicable to automatic and unattended data acquisition of real-time kinetics of slow liquid homogeneous reaction process， especially for the stability monitoring of natural pigments. The color of mulberry pigments was related to pH values， and it presented bright red color at pH 3. Thermal， light irradiation and oxidative degradations of mulberry pigments followed first-order kinetics， the apparent activation energy of thermal degradation was 60.2 kJ/mol. High temperature， ultraviolet exposure and oxidant sped up the pigment degradation significantly. Low temperature， ultraviolet barrier package materials and a proper amount of VC showed protective effects.

Abstract:This paper measured the effect of high pressure processing on the structure and properties of lactoferrin （LF） in different buffer systems [（phosphate buffer （PBS）， Tris-HCl buffer （Tris-HCl）， citrate buffer （CBS）] by Zeta potential， free sulfhydryl content， ultraviolet spectrum， fluorescence spectrum， circular dichroism and protein solubility. The results showed that the resistance of LF to high pressure in the three buffers was as follows： CBS>Tris-HCl>PBS， that was， the tertiary structure and solubility of LF in PBS were most easily changed by high pressure. The adsorption of anions in the buffer solution caused the isoelectric point of LF to change. The surface Zeta potential of LF in PBS， CBS， and Tris-HCl was -3.86-20.07， -6.89-19.6 mV and 1.24-23.37 mV， respectively. Accordingly， the adsorption capacity of anions was CBS＞PBS＞Tris-HCl. 600 MPa treatment in Tris-HCl at pH 7 caused a large amount of precipitation of LF， where the free sulfhydryl content reached the highest， 6.23 μmol/（L·g）， and the protein solubility was the lowest， 45.28 μg/mL. At pH 3， the α-helix content of LF was significantly lower than other samples， and the content of random coils was significantly higher than other samples， indicating that the secondary structure of LF was relaxed under acidic condition and was more susceptible to high pressure.