Abstract:Protein is one of the most important nutrients for human. However， husbandry-based protein supply faces up to severe environment pollution， extensive land use and freshwater withdrawals， which cannot meet the increase requirements of protein due to increasing population and improved living standard. Microbial protein can be quantitatively produced using less resource， which has high production efficiency and low carbon dioxide emission. As an important alternative protein， microbial protein manufacturing provides important approach for sustainable protein supply. In this work， we firstly discussed the importance of microbial protein manufacturing for sustainable protein supply. Next， advances of microbial protein manufacturing were systematically summarized. Finally， perspectives on important research direction of microbial protein manufacturing were discussed. Developing and applying highly efficient microbial protein manufacturing is of great importance for protein resources supply.

Abstract:Vegetable protein is a sustainable and important source of protein. Supplementing or replacing some of the deficiencies of animal protein with vegetable protein has become a research hotspot in food industry science and technology. This paper mainly introduces the structural analysis and flexible processing theory of vegetable protein at home and abroad， expounds the principle and research progress of vegetable protein processing technology， the application of vegetable protein in the food industry， and points out the existing problems and future development trends， in order to provide future vegetable proteins. The research and development of protein processing technology provides ideas and references.

Abstract:Microalgae are rich in various nutritional components and active substances， which are regarded as a promising raw material for food with great market potential. Generally， the protein content in microalgae is higher than traditional crops and the protein nutritional value， quality and techno-functional properties are better than crop proteins. Thus， microalgal protein is considered as a kind of supplement or substitute protein for foods. In this paper， the application and research progress of microalgal protein， which can be used as new resource of food ingredient， are mainly expounded from the aspects of protein separation methods， nutritional and physicochemical properties， and their biological activities. Additionally， the development potentials and existing problems of microalgae protein application in foods are also briefly analyzed. This paper is expected to provide references for the scholars who are exploring new food resources and developing future foods.

Abstract:Pursuing a better life promotes the development the protein for diversification， differentiation， and personalization. Because of the continuous growth of population and improvement in living standards， there is an urgent need to increase the supply of large-scale， inexpensive， sustainable， and high-quality protein from renewable feedstocks. The metabolic network and regulatory of microbial were engineered and designed by synthetic biology and metabolic engineering， obtaining microbial cell factories， and providing a promising avenue toward sustainability for the production of amino acids and protein from renewable feedstock. In the present review， we focus on the research progress in the ammonia synthesis pathway， microbial amino acids production， and microbial protein production， which is expected to serve as a reference for amino acids and protein production by microbial cell factories.

Abstract:Insect protein is a novel type of protein resource. Because of rich varieties and sustainable development insect protein may answer the requirements of the 'Greater Food Approach'. In this paper， resource characters， development dynamics and processing methods of edible insect protein were reviewed. The factors limiting the development process were analyzed. This may help to offer a scientific basis for the exploration and utilization of edible insect protein resource.

Abstract:In order to investigate the hydrolysis capacity of Lactobacillus helveticuson casein and the discrepancy of the peptides in the fermented products， the consumption the two major caseins， peptide dynamic change and peptidomics were studied， as well as the hydrolysis genes of the two Lactobacillus helveticus strains and the cell-envelope protease activity during fermentation. The results showed that the hydrolysis of β-casein and αs1-casein by the two Lactobacillus helveticus strains was significantly different with no obvious preference. The total contents of peptides increased initially during fermentation. The peptides with molecular weights of 2 000-10 000 u showed similar trends， while the peptides with molecular weights of 180-500 ugradually accumulated in the late stage of fermentation. The analysis by LC-MS/MS indicated that the peptides showed heterogeneity after 24 h of fermentation， with 7M3 generating more specific peptides， mostly from the f78-99 region of β-casein from the C-terminus of αs1-casein， whereas M108 produced more peptides derived from the N-terminal and intermediate sequences of αs1-casein. The two strains displayed different single cell-envelope proteinase gene and transport systems. The higher enzyme activity of M108 in the early stage of fermentation was observed.

Abstract:Lactobacillus plantarum is a kind of facultative heterotrophic and facultative anaerobic homo-fermenting lactic acid bacteria， which has glycosidase activity and plays an important role in improving food flavor and fermentation characteristics. Using PCR technology， 8 6-phosphor-β-glucosidase genes from the glycoside hydrolase 1 family of L. plantarum WU14 were successfully cloned. It is showed that eight genes contain a complete open reading frame， and the amino acid sequence alignment reveals there are two conservative catalytic sites of the 6-phosphor-β-glucosidase gene in glycoside hydrolase 1 family， and the sequence identity is between 32%-74%. The results of SDS-PAGE shows that all proteins were expressed in E. coli. Among them， BglAW14， BglCW14， and BglFW14 are partially soluble expression. A purified and recovered to single target band was obtained， and the rest are expression of inclusion bodies. Bioinformatics analysis tells that the encoded proteins have weak hydrophobicity， and none of them have signal peptides and transmembrane structures. The prediction of subcellular structure shows that， except for BglEW14 mainly distributes in the secretion and BglHW14 mainly exists in the cell membrane. The remaining six genes are all present in the cytoplasm. The cloning， protein expression and biological sequence analysis of 6-phosphor-β-glucosidase genes laid a theoretical foundation for further exploring the molecular research of 6-phosphor-β-glucosidase derived from Lactobacillus plantarum.

Abstract:Objective: The inhibition of agar-oligosaccharides on lipopolysaccharide (LPS) -induced inflammatory response in macrophage RAW264.7 and its mechanism were investigated in this study. Methods: The molecular structure of agar-oligosaccharides was analyzed by Fourier transform infrared spectroscopy， nuclear magnetic resonance and high performance liquid chromatography. The inflammatory response model was established using LPS-induced macrophage RAW264.7， and the effects of agar-oligosaccharides on cell viability， intracellular nitric oxide(NO)， tumor necrosis factor-α (TNF-α) and reactive oxygen species (ROS) levels of RAW264.7 were determined. Furthermore， the expression and phosphorylation levels of c-Jun N-terminal kinase (JNK)， extracellular signal-regulated kinase (ERK)， and protein kinase p38 in the mitogen-activated protein kinase (MAPK) signaling pathway were analyzed by Western blot. Results: Molecular structure identification results of Agar-oligosaccharides displayed galactose sugar ring structures with molecular weights ranging of 1065.5-1308.2 u. Agar-oligosaccharides could increase the cell viability of macrophage RAW264.7 with LPS-induced inflammatory response， decreased the intracellular NO， TNF-α and ROS levels in a concentration-dependent manner at 0~250 μg/mL， and inhibited the increase of LPS-induced phosphorylation levels of MAPK family kinases JNK， ERK， and p38. Conclusion: Agar-oligosaccharides can inhibit LPS-induced inflammatory response in macrophage RAW264.7， which may be related to the hindering of MAPK signal transduction.

Abstract:Alcohol dehydrogenase is a key enzyme in the final synthesis of β-phenylethanol in Huangjiu yeast， which comes from the Ehrlich pathway. To explore the differences and enzymatic analysis of Adh1pHJ， the ADH1 of Saccharomyces cerevisiae HJ and Saccharomyces cerevisiae S288C were used as templates respectively to amplify the target gene by PCR. The expression plasmid pET-28a(+)-ADH1 were constructed， and transformed into Escherichia coli BL21(DE3) cells to obtain high expression induced by IPTG. The crude enzymes were obtained after ultrasonic fragmentation， and then purified by affinity chromatography with AKTA pure. Finally the enzymatic analysis were explored. Using phenylacetaldehyde as substrate， it was found that the enzyme activity(231.51 U/g) of Adh1pHJ was 13.79% higher than that of Adh1pS288C (203.48 U/g)， and the Km value of Adh1pHJ (0.524 μmol/L) was less than that of Adh1pS288C (0.759 μmol/L)， which indicated that the affinity between Adh1pHJ and substrate was higher. From the kcat/Km value， it is found that the catalytic efficiency of Adh1pHJ[0.406 L/(μmol·min)] is higher. The tolerance of Adh1pHJ to β-phenylethanol and ethanol was higher than that of Adh1pS288C. This study provides a method and theoretical basis for the analysis of the structure and properties of Adh1p， and also provides a reference for the industrial production and development of β- phenylethanol.

Abstract:In order to analyze the mechanism of isoamyl alcohol synthetic metabolism in the fermentation process of Saccharomyces cerevisiae， this study used the native Saccharomyces cerevisiae LFE1225 as the experimental strain， with simulated wine fermentation. The isoamyl alcohol production rate， nitrogen source utilization， transcriptomics in the early， mid-log and end-log phases of the fermentation were compared and analyzed. The results showed that the synthesis and accumulation of isoamyl alcohol mainly occurred in the logarithmic phase； the synthesis rate of isoamyl alcohol in the initial stage of fermentation is the fastest， and it has a very significant positive correlation with ethanol synthesis rate， higher alcohol synthesis rate and sugar consumption rate. Saccharomyces cerevisiae LFE1225 utilized a large amount of YAN in the initial stage of fermentation and synthesized more leucine； after entering the logarithmic phase， leucine begins to be rapidly utilized. During the logarithmic period of fermentation， the expression of LEU2， BAT1/2， ILV5， LEU9， PDC6， THI3， ADH6 related to isoamyl alcohol metabolism of Saccharomyces cerevisiae LFE1225 were down-regulated， it was consistent with the change trend of isoamyl alcohol synthesis rate during this period； The 4 isoamyl alcohol metabolism-related genes， including BAP2， ILV2， PDC1， and SFA1 has the same expression trend with the 14 transcription factors including GAT1， ADR1， UPC2， GCN4， RPN4， RFX1， CUP2， RIM101， RLM1， SUM1， TYE7， GAL4， RME1 and USV1. And the transcription factors may be involved in the isoamyl alcohol metabolism regulation of Saccharomyces cerevisiae LFE1225. This study provides a reference for further understanding the metabolic mechanism of isoamyl alcohol in Saccharomyces cerevisiae， and provides a basis for the directed breeding of low/high isoamyl alcohol strains.

Abstract:The formation kinetics of 5-hydroxymethylfurfural was investigated in sugar-peptide model systems (glucose-glutamate dipeptide). In this paper， glucose-glutamate dipeptide and 5-hydroxymethylfurfural(5-HMF) contents were indicated by kinetic analysis method. The kinetics analysis showed that the consumption of glucose and glutamate dipeptide were all followed first-order kinetics in glucose-glutamate dipeptide models at 90-110 ℃ (0-6 h). And the degration rate of reactants increased gradually with temperature. HMF formation followed zero-order kinetic at 90-95 ℃(0-6 h) and followed first-order kinetics at 100-110 ℃(0-6 h) in glucose-glutamate dipeptide models.

Abstract:In this paper， an inclusion complex of adlay bran polyphenols(ABP) with β-cyclodextrin (β-CD) was prepared by freeze-drying method. The inclusion complex was then characterized by ultraviolet spectroscopy (UV)， fourier transform infrared spectroscopy (FTIR)， X-ray diffraction (XRD)， thermogravimetry-differential scanning calorimetry (TG-DSC) and scanning electron microscope (SEM). Further， the antioxidant activities of ABP and ABP/β-CD inclusion complex were evaluated by ferric reducing antioxidant power (FRAP) and 2，2′-Azino-Bis (3-Ethylbenzothiazoline-6-Sulfonic Acid) diammonium salt (ABTS) radical cation scavenging activity assays. It was found that the FRAP and ABTS radical cation scavenging activity of ABP/β-CD inclusion complex were 5.6% and 8.9% higher than that of ABP(P<0.05)， respectively. In addition， the light stability of the aqueous solution of ABP and ABP/β-CD inclusion complex was investigated by measuring the retention rate of total phenolic content. After 48 hours of light， it was found that the retention rate of total phenolic content in ABP/β-CD inclusion complex was 1.20 times higher than that in ABP (P<0.05). These results showed that ABP/β-CD inclusion complex was successfully prepared by freeze-drying method， and the inclusion complex had good antioxidant activity and aqueous light stability， which could be used as a new functional food ingredient.

Abstract:To study the inhibitory effects of thioether spices on two common food-borne pathogens--Salmonella and Vibrio parahaemolyticus， and explore the relationship between the antibacterial activity of spices and their structure. The diameter of the inhibition zone was measured by the filter paper method， and the minimum inhibitory concentration (MIC) of different spices was determined by the broth dilution method， and the growth curve was drawn using the absorbance value of the bacterial liquid at 600 nm. qRT-PCR was used to study its regulatory effect on the specific virulence gene tdh gene of Vibrio parahaemolyticus. The results show that these sulfide fragrances have different effects on the two bacteria. Among them， methyl propyl disulfide， methyl furfuryl disulfide， furfuryl isopropyl sulfide， diallyl sulfide， diallyl disulfide has an inhibitory effect on both bacteria. And diallyl disulfide has the most significant inhibitory effect. The MIC for Salmonella is 19.5 mmol/L and that for Vibrio parahaemolyticus is 4.88 mmol/L. Diallyl disulfide significantly inhibits the expression of the virulence gene tdh of Vibrio parahaemolyticus and is positively correlated with the concentration. Studies have shown that the number of sulfur atoms and allyl groups in thioether spices will promote their antibacterial effect. Among them， diallyl disulfide has the best antibacterial effect， laying a foundation for the application of thioether spices in food basis.

Abstract:Garlic oil was extracted from garlic and qualitatively analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). Using enzyme activity real-time monitoring technology， it was revealed that Garlic oil， diallyl disulfide (DADS) and diallyl trisulfide (DATS) had partial inhibitory effects on glucose 6 phosphate dehydrogenase (G6PD) activity， and the inhibition was a mixed inhibition of competitive and non-competitive by enzymatic reaction kinetics； Molecular fluorescence technique analysis further showed that DADS/DATS had static quenching effect on G6PD， and there was a binding site for DADS/DATS and G6PD protein； Thermodynamic analysis revealed that the DADS-G6PD system was mainly combined through hydrophobic interactions， and the DATS-G6PD system was mainly combined through hydrogen bond and van der Waals force； 3D molecular docking and 2D molecular docking techniques further confirmed that DADS/DATS could enter the G6PD molecule， and the binding performance of DADS and G6PD was better； DADS could form hydrophobic interactions with Ala-377， Val-376， Phe-216， Gly-222， Phe-221， Pro-223 and other hydrophobic amino acid residues around the G6PD binding site， and interacted with Arg-219， Asn-218 ， Lys-275， Arg-215， Trp-225 and other polar amino acid residues formed electrostatic attraction， and hydrophobic interactions were dominant. DATS could form hydrophobic interactions with Phe-253， Gly-254， Ala-335， Ile-472， Ile-255， Leu-469， Leu-305 and other hydrophobic amino acid residues around the G6PD binding site， and interacted with Arg-175， Lys-476， Arg-257， Thr-334， Thr-333， Glu-473 and other polar amino acid residues formed electrostatic attraction. In addition， S in the center of DATS could form a hydrogen bond with Phe235 of G6PD， with a bond length of 3.2 ?魡. Hydrophobic interaction， electrostatic force and hydrogen bonding were the main modes of action of DADS/DATS on G6PD.

Abstract:In order to explore the mechanism of HPTS in inactivation of Bacillus subtilis spores. In this paper， HPTS (200 MPa combined with 25 ℃， 65 ℃， 75 ℃； 550 MPa combined with 25 ℃， 65 ℃， 75 ℃； holding time: 20 min) was used to treat Bacillus subtilis spores. The survival concentration， UV absorption leakage， inner membrane permeability and spore composition of HPTS before and after HPTS treatment were studied by plate technology， UV spectrophotometry， flow cytometry and infrared spectroscopy. The results showed that after treated with HPTS， the survival concentration of spores decreased significantly (P<0.05)， the leakage of ultraviolet absorption increased， and the endospore membrane was damaged， resulting in the enhancement of the permeability of spore endomembrane. The results of Fourier transform infrared spectroscopy (FTIR) showed that the main differences of Bacillus subtilis spores before and after HPTS treatment were protein， lipid， nucleic acid and polysaccharide. The secondary structure of protein changed from order to disorder， and the stability of protein decreased. Therefore， HPTS can effectively destroy the permeability barrier of water molecules， lipid， protein， nucleic acid and polysaccharide structure of spore membrane， so as to reduce the resistance of spores， affect the metabolism of spores and inactivate the spores. It provides a theoretical basis for HPTS to inactivate Bacillus subtilis spores and promotes the successful application of HPTS in food processing.

Abstract:During food processing， the self-assembly behavior of food ingredients will produce a large number of micro-nano colloidal particles. The absorption， transport and physiological functions of this kind of micro-nano colloidal particles in the human body are not yet completely clear. This study investigated the effects of nanoparticles derived from freshwater clam soup on immune cells in the mucosa of alimentary tract. In the macrophage model derived from the mucosa of alimentary tract， the process of the nanoparticle entering the cell and its effect on cytotoxicity， cell membrane potential and mitochondrial superoxide free radicals were observed. The results showed that the nanoparticles derived from freshwater clam soup are not obvious cytotoxicity， can enter the macrophage cells and maintain the granular structure， and can improve the oxidative stress state of the macrophages. The results of this study provide evidence of direct interaction between food nanoparticles and immune cells， implying a way of interaction between food and the human body.

Abstract:Objective: The purpose of the study was to explore the effects of black wheat flour on hypolipidemic action， liver and kidney function of rat with hyperlipidemia， so as to lay the foundation of a dietary therapy for hyperlipidemia. Methods: A total of 50 rats were randomly divided into five groups according to their body weight， 10 rats in each group. The normal control group rats were fed with a standard diet， whereas the other four groups of rats were fed with a high-fat diet to induce dyslipidemia. Hyperlipidemia rats were randomly divided into dyslipidemia control group (DC) and black wheat flour high dose group， middle dose group and low dose group. Rats were fed with corresponding food for 6 weeks， blood lipid levels and body weight of the rats were detected， and the pathological sections of the liver and kidney tissues were observed. Results: 1) The weight-gain-ratio of all dose groups rats were significantly lower than that of the control group rats， and it was significantly lower in black wheat high dose group when compared to the DC group. 2) Compared with before dietary intervention， the blood lipid levels of rats in the three dose groups were significantly reduced， and TC and LDL were lower than that of the DC group， all dose groups serum levels is no statistically difference. 3) The pathological examination showed that the hepatocyte steatosis was at lower level， and renal lesion was alleviated in black wheat all dose groups， compared to the DC. Conclusions: Black wheat flour can lighten the weight of hyperlipidemia rats， ameliorate the lipid metabolism disorder effectively， alleviate the liver and kidney injury caused by hyperlipidemia.

Abstract:In order to determine 6'-O-caffeoylarbutin protection of type I diabetes in mice， mice were injected alloxan drugs to create type I diabetes model， and diabetic mice were also treated with 6'-O-caffeoylarbutin. Mice were randomly divided into 5 groups: normal control group， model group， positive control group， 6'-O-caffeoylarbutin low-dose group (100 mg/kg/d bw)， and 6'-O-caffeoylarbutin high-dose group (200mg/kg/d bw). After continuous intragastric administration for 4 weeks， glucose tolerance， organ index， serum index， liver and kidney indexes of mice in each group were measured， and pathological examination of pancreas， liver and kidney tissues was conducted. The results showed that the 6'-O-caffeoylarbutin can reduce type I diabetes mice serum total cholesterol， triglycerides， free fatty acid and low density lipoprotein cholesterol， high-density lipoprotein cholesterol and insulin levels. 6'-O-caffeoylarbutin can also increase the activity of superoxide dismutase， catalase and glutathione peroxidase in liver tissue， and reduce the content of malondialdehyde， alanine aminotransferase， alkaline phosphatase and urea nitrogen in kidney tissue. Conclusion: 6'-O-caffeoylarbutin has a certain hypoglycemic effect， and can effectively alleviate the injury of liver， kidney， pancreas and other tissues in type I diabetes mice.

Abstract:Objective: To study hypoglycemic activity of diosmetin on type Ⅱ diabetic mice. Methods: Activities of four phenolic compounds in Chrysanthemum morifolium including diosmetin， isochlorogenic acid C， luteolin and morin， were analyzed using molecular docking and α-amylase， α-glucosidase experiments. Type Ⅱ diabetic mice model was developed using high sugar and fat feed combined with streptozotocin(STZ) method. Effects of diosmetin on carbohydrate metabolism， lipid metabolism and oxidative stress in mice were investigated using homeostasis model assessment of insulin resistance (HOMA-IR)， total cholesterol (TC) and glutathione peroxidase (GSH-Px) methods. Results: Diosmetin effectively alleviates the symptoms of diabetic mice such as polyphagia， polydipsia and low body weight， significantly reduces fasting blood glucose(FBG)， insulin (I) content and insulin resistance index (P<0.05)， decreases content of glycosylated serum protein(GSP)， and relieve the abnormity of oral glucose tolerance test (OGTT). Besides， diosmetin reduces contents of total triglycerides (TG)， TC and low density lipoprotein cholesterol (LDL-C) in the serum， and increase content of high density lipoprotein cholesterol (HDL-C). Diosmetin also improves total anti-oxidation capacity (T-AOC) and activities of superoxide dismutase(SOD) and GSH-Px， reduces malondialdehyde(MDA) content， and significantly reduces activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) (P<0.05). Conclusion: Diosmetin exhibits hypoglycemic activity on type II diabetic mice， and possesses mitigating effects on oxidative stress and lipid metabolism disorders caused by diabetes.

Abstract:Objective: To investigate the effects of oat barley powder on glucose and lipid metabolism and oxidative stress in type II diabetic mice. Methods: ICR mice were fed high-fat diet， combined with small dose (50 mg/kg) intraperitoneal injection of streptozotocin to establish a diabetic mouse model. The adult mice were randomly divided into a high-fat group， a positive control group (metformin 200 mg/kg·d) and a high-fat oat barley powder group. Observe the changes in body weight and blood glucose of each group during the sample administration， take the blood from the eyeball after 6 weeks of sample administration， and detect blood lipids， fasting blood sugar and serum insulin. The liver tissue was collected to determine the activity of malonaldehyde (MDA)， superoxide dismutase (SOD)， glutathione peroxidase (GSH-Px) activity， and glutathione(GSH). Results: Compared with the high-fat group， the high-fat oat barley powder group can effectively alleviate the symptoms of diabetic mice. HE staining showed that oat barley powder improved the pathological state of the mouse pancreas； it could significantly reduce the fasting blood glucose level of type II diabetic mice (P<0.05)， it has a very significant effect on reducing HDL-c and LDL-c content (P<0.01)， there is no significant difference in TG content (P>0.05)， and it has a significant effect on TC reduction (P<0.05)； The level of GSH-px was significantly increased (P<0.05)， the level of SOD was significantly increased (P<0.05)， and there was no significant difference in the content of MDA(P>0.05). Compared with the high-fat group， the high-fat oat barley powder group had a very significant increase in serum insulin (P<0.01)， and the high-fat group had a very significant increase (P<0.01) compared with the blank control group. The content of lactic acid bacteria in the intestinal flora in the high-fat group fed oat barley meal was improved compared with the high-fat group. Conclusion: Oat barley powder has the effect of lowering blood sugar in type II diabetic mice， and has a certain regulatory effect on the disorder of blood lipid metabolism. The specific mechanism of lowering blood sugar and lipid may be related to improving the body's antioxidant activity.

Abstract:To investigated the effect of vacuum low-temperature preparation and reheating on the edible quality of abalone(Haliotis discus hanai)， the fresh abalones were vacuum-packed and subjected to low-temperature heat treatment at 50 ℃ - 3 h， 60 ℃ - 1 h and 70 ℃ - 1 h， respectively. Traditional cooking treatment at 100 ℃ - 2 h under atmospheric pressure was used as a control group to compare the cooking loss， texture properties， color， flavor and sensory characteristics of the different treated samples. The results showed that the vacuum low-temperature preparation combined with reheating could reduce the steaming loss of abalone compared with the traditional cooking method. First， in terms of texture， in addition to elasticity， the hardness， cohesiveness， chewiness and resilience of the vacuum low-temperature preparation and reheating treated samples changed in the direction of making the overall texture more harmonious. Notably， the reheated 70 ℃ - 1 h group showed significantly better tenderness than the control group. Second， all samples presented an increase in color parameters， but the color difference ΔE was smaller for 60 ℃ - 1 h and 70 ℃ - 1 h samples. Meanwhile， both vacuum low-temperature preformation and reheating could promote the production of good flavor compounds. Furthermore， the sensory assessment results were generally consistent with the trend of each index and significantly correlated with chewiness， resilience and shear force (P<0.05). Conclusion: 70 ℃ - 1 h treatment after vacuum packing is more suitable as a pre-processing condition for abalone.

Abstract:Ciba pepper is a traditional characteristic pepper product in Guizhou. In order to clarify the correlation between the key processing technology and the flavor and quality of Ciba pepper， 10 different processing technologies of Ciba pepper were used as the research object， and the electronic tongue and gas phase ion mobility spectrometry (GC-IMS) were used. The effects of different processing conditions on the flavor and quality of Ciba pepper were compared and analyzed. The results showed that: 80 kinds of volatile flavor compounds were detected in 10 kinds of Ciba pepper samples， including 22 kinds of aldehydes， 15 kinds of alcohols， 12 kinds of ketones， 10 kinds of esters， 8 kinds of terpenes and 13 kinds of other compounds. The flavor fingerprint information of samples changes significantly with the different processing technology； The Ciba pepper electronic tongue produced by the standardized technology had better taste freshness， richness and sensory score. Among them， three kinds of dry capsicum were selected， cooked at high temperature for 6 min， fried with golden capsicum seeds， and crushed with radium. The flavor quality of Ciba capsicum was the best. The results provide theoretical basis and data support for large-scale processing and quality control of characteristic Ciba pepper products.

Abstract:In order to optimize the technological conditions for preparing ACE inhibitory peptide of sheep casein by enzymatic hydrolysis， and a new ACE inhibitory peptide was screened and identified from casein hydrolysate. ACE inhibitory peptide was prepared from sheep cheese protein by five proteases enzymatic hydrolysis， and taking molecular weight distribution， degree of hydrolysis and inhibition rate of angiotensin-I-converting enzyme (ACE) as indicators to screening the most suitable protease. The single factor and response tests were used to optimize enzymatic hydrolysis conditions. The amino acid sequences of components less than 3 ku were identified by Orbitrap Fusion Lumos Tribrid MS， and the potential ACE inhibitory peptides were screened and determining their IC50 values after synthesis. The inhibition kinetics of enzyme was determined by Linewaver-Burk mapping， and molecular docking was used to explain the mechanism of peptides inhibition of ACE. The results showed that alkaline protease was the most suitable protease， the optimal enzymolysis conditions were as follows: pH 6， substrate concentration of 8%， enzyme/substrate ratio(E/S) of 4%， temperature at 55 ℃ and enzymatic hydrolysis time for 90 min. The ACE inhibition rate of casein antihypertensive peptide prepared under this condition was 99.1%. A total of 484 peptides were identified in the fraction less than 3 ku， among which 10 peptides had been verified to have ACE inhibitory activity. A novel peptide LFRQFY (derived from αs1-casein) were found to have highly inhibition potency with IC50 values of (7.9±1.7) μmol/L and exhibiting mixed inhibition patterns. The molecular docking results revealed that LFRQFY were mainly attributed to forming very strong hydrogen bonds with ACE amino acid residues Ala354 (S1 pocket) and His353 (S2 pocket)， and showed significant antihypertensive activity in vitro.

Abstract:Through Fourier infrared spectrometer (FT-IR)， rheometer， texture analyzer， low-field nuclear magnetic resonance (LF-NMR) and differential calorimetry scanner (DSC)， used corn starch as raw material， the aging and water migration of corn starch with different content of soy isoflavones was analyzed the impact of characteristics. The results showed that the starch aging degree deepened during the storage period. After adding soy isoflavones， the change rate of the elastic modulus of starch gel was reduced， and the short-term aging of corn starch was delayed. With the same storage period， as the concentration of soy isoflavones increased， the starch retrogradation rate decreased significantly； the hardness value decreased， the gel texture was softer； the hydrogen bond absorption peak was red-shifted， the values at R1047/1022 and R995/1022 gradually decreased， and the relative degree of order decreased； the content of bound water and non-flowing water increased， and the free water content decreased. Soy isoflavones could effectively inhibit the long-term aging of starch， the study could provide basic data on the effect of flavonoids on starch retrogradation properties.

Abstract:Moisture migration of Antarctic krill meat during multiple freeze-thaw cycles was analyzed using low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) techniques， combining with the results if the loss rate of thawed juice and centrifugal loss rate. The structure and protein changes of myofibrils after multiple freeze-thaw cycles were observed by electron microscopy， optical microscopy and SDS-PAGE， and the lipid oxidation was determined by thiobarbituric acid (TBA) value. The results showed that thawing loss rate and centrifugal loss rate of Antarctic krill meat significantly increased (P＜0.05) and the brightness of the MRI hydrogen proton-weighted pesudo-color map gradually decreased with increase if freeze-thaw cycles times， indicating that the moisture content if Antarctic krill meat gradually deceased. As seen from LF-NMR results， there was no significant change in the content of strongly bound water and bound water (P＞0.05)， the content of immobile water significantly reduced (P＜0.05)， and the content of free water significantly increased (P＜0.05)， indicating the immobile water in Antarctic krill meat was easily converted to free water during freeze-thaw cycles. According to the correlation results， the NMR parameters of immobile water and free water had a very significant correlation with the thawing rate (P＜0.01) after multiple freeze-thaw cycles. Due to the growth of ice crystals， the myofibril arrangement of Antarctic krill meat changed from neat and compact to disorder， and even broken. Further， SDS-PAGE results showed that the myosin heavy chain was completely degraded， and that the actin， troponin T and myosin light chain were degraded to varying degrees. Nevertheless， the TBA value did not change significantly(P＞0.05). The above results showed that multiple freeze-thaw cycles could cause moisture migration and protein degradation of Antarctic krill meat， but the effect on lipid oxidation is not significant.

Abstract:River crab meat samples were preserved with high power pulse microwave (HPPM) and eugenol. The total viable counts (TVC) and total volatile base nitrogen (TVB-N) contents were determined during 5-day storage. The microbial diversity of samples treated with different preservation methods was analyzed by high-throughput sequencing. Results showed that HPPM combined with eugenol could significantly delay the increase of TVC and TVB-N contents during storage. The dominant spoilage bacteria in crab meat samples was Bacillus. Addition of 2 μL/g eugenol and treating with HPPM at 900 kW， 200 Hz for 5 min had a strong inhibitory effect on the growth of Bacillus.

Abstract:Aflatoxin B1 (AFB1) is a predominant toxin detected abundantly and has been implicated in the etiology of human hepatocellular carcinoma. In this study， a novel quantitative recognition strategy of Aflatoxin B1 was proposed. The reaction medium for AFB1 was built using colloidal gold immuno-chromatography and information of the results was obtained using the technology of charge coupled device (CCD). An expressing method called color space was established to express the information of AFB1. The path can be used to obtain accurate measurement of the AFB1. The results showed that the color distance of T line and C line (AFB1 test card) was linearly correlated with the concentration (R2=0.986). The precision of the experiments was as follows: the relative standard deviation of the high concentration (20 μg/kg) was <2.7% for more than 97% dots， and that of the other two samples was <3.6% for more than 90% dots. This showed that the degree of coincidence of information in pixels between parallel color images(the same sample) was high. The maximum error between the linear results obtained by machine learning methods and the linear results obtained by 30 groups of parallel experiments is 5.93%， additionally， the results had no significant difference between RqM-AFB1 and HPLC test (P＞0.05). Thus， this method provides an effective way to improve fast quantitative and accurate identification of Aflatoxin B1.

Abstract:Objective: The development of a method for detecting Cronobacter spp in milk powder based on CRISPR/Cas12b. Methods: Firstly， the amplification primers and guide RNAs were designed and synthesized based on the specific gene sequence of Cronobacter spp. The conditions， specificity and reaction system were optimized， and the sensitivity and reproducibility of the system were validated using artificially contaminated samples. Results: The results showed a high specificity and sensitivity of this method - the sensitivity reached 0.01 ng/μL； samples with initial bacterial counts less than 10 CFU/g could be detected； and the detection limit was<10 CFU/100 g. 51 commercial milk powder samples were later tested using our established method， and the results were consistent with those obtained by traditional national standard method. Conclusion: As such， the CRISPR/Cas12b method established in this study can be used for rapid detection of Cronobacter in milk powder.

Abstract:Objective: The serotype and genotype of 399 Salmonella isolates recovered from retail raw chickens collected from Guangdong province (n=130)， Guangxi province (105)， Fujian province (82) and Shanghai City (82) were studied to protect food safety. Methods: The serotype was tested and determined using antiserum via serum agglutination method that recommended by the World Health Organization(WHO). The genotype was determined according to the protocol of pulse field gel electrophoresis(PFGE) that issued by the U.S. Centers for Disease Control and Prevention(CDC)， the DNA profiles were clustered using BioNumerics software. Results: Forty-seven serotypes were detected among 399 Salmonella isolates， among which， Salmonella Enteritidis (17.04%)， S. Typhimurium (16.04%)， S. Indiana(14.04%)， S. Thompson (9.02%)， S. Agona(7.52%) and S. Rissen (3.76%) were the predominant serotypes. Salmonella Derby， S. Infantis， S. Duesseldorf， S. Edinburgh and S. Bellerue were rarely detected. Salmonella Typhimurium was the most prevalent serotype in Guangdong province (20.00%)； whereas， Salmonella Enteritidis was the common serotype in Guangxi (18.10%) and Fujian province (29.27%)； S. Indiana was the main serotype of Shanghai. PFGE genotype of the isolates with same serotype that recovered from different samples were similar or highly similar within each province. Isolates with same serotype recovered from different samples and provinces exhibited diverse genotypes. Conclusions: Salmonella isolates recovered retail raw chickens collected from Guangdong， Guangxi， Fujian and Shanghai not only exhibited diverse serotypes and genotypes， but also high homology in the same region.

Abstract:Shewanella putrefaciens is a kind of specific spoilage organism of aquatic products， which possess strong cold adaptability and spoilage ability. Two-component signal transduction systems (TCSs) is one of the most important regulatory systems in bacteria， and plays an important role in the perception and response of bacteria to complex environment. In order to explore distribution and function of TCSs in S. putrefaciens. In this paper， the distribution， classification， structure and function of TCSs in S. putrefaciens from aquatic products， were systematically analyzed by bioinformatics methods， including whole genome identification， multiple sequence alignment， phylogenetic analysis， protein structural prediction and interaction protein analysis. The results showed that there were 31 histidine kinases (HKs)， 36 response regulators(RRs)， 3 pairs of TCSs and 3 fusion HKs in S. putrefaciens WS13. There are 16 types of structural domain compositions in HKs， 15 of which possess HATPase_c kinase catalytic domains. RRs have10 types of structural domain compositions， all of which contain REC domains. Multiple sequence alignment and evolutionary analysis showed that HKs and RRs with different structural domains had different evolutionary relationships， which suggested functional diversity of these proteins. The biological functions of 3 pairs of TCSs and 3 fusion HKs were predicted to be mainly involved in response to signal stimulation， regulation of various metabolic processes and transport of substances in cells. Moreover， 3 fusion HKs were related to the formation of trimethylamine. The results provide references for further exploring the function of TCSs in S.putrefaciens from aquatic products.

Abstract:Microbial community structure and succession law among Sichuan bran vinegar during fermentation were analyzed by high-throughput sequencing technology. The result showed that the abundance indexes of bacterial community and fungal community were the largest on the first day of fermentation， while the diversity indexes of bacterial community and fungal community were the largest on the first day and the 23th day of fermentation， respectively. The structure of bacterial community and fungal community in vinegar was analyzed at the phylum level， the dominant phyla of bacteria was Firmicutes， and the dominant phylum of fungal was Ascomycota. The structure of bacterial community and fungal community in vinegar was analyzed at the species level， the dominant bacterial species was Lactobacillus acetotolerans and Acetobacter pasteurianus， which reached the maximum proportion of 54.47% and 84.54% on the 7th and 25th days of fermentation， respectively. The dominant species of fungal was Saccharomyces cerevisiae， which reached the maximum proportion of 97.94% on the 5th day of fermentation. In addition， Aspergillus spp.， Alternaria spp.， were detected in vinegar. Through the study on microbial community structure and succession law in the fermentation process of Sichuan bran vinegar， it was order to anchor the dominant microbial of Sichuan bran vinegar and the quality of bran vinegar can be improved by regulating the micro-ecological structure of the fermentation environment.

Abstract:Honey is a traditional natural health food， but the market is mixed and criticized. It is very important for the healthy development of honey market to distinguish mature honey from commercial dehydrated honey. According to the bionics principle that bees can distinguish the quality of honey， a tissue sensor was prepared by using a glassy carbon electrode modified by honeybee mouthparts tissue， and the honey samples were detected by cyclic voltammetry. According to the detection signal of the sensor， the linear regression analysis model of the detection sample was built to determine the best mass concentration that the sensor could identify， and the model and the discrimination effect were verified. The results showed that the model combined with the tissue sensor could effectively identify mature honey and commercial dehydrated honey， and the optimal concentration range was 0.16-0.18 g/mL， the optimal concentration range of mature honey and fructose syrup is 0.08-0.1 g/mL， and the results were stable and reliable. These data proved that honeybee tissue sensor can be used for honey detection， and the linear model of honey standard products can stably and reliably identify the types of honey to be tested.

Abstract:To investigate the nutritional properties of European eel muscle protein， the amino acids composition and in vitro digestion characteristics of muscle and its isolated water-soluble protein(WP) and salt-soluble protein (SP) were analyzed. The essential amino acids of muscle， WP and SP accounted for 37.81%， 36.53% and 42.71%， respectively. Valine was the first limiting amino acid of muscle protein and SP， while that of WP was methionine + cysteine. The essential amino acid index， biological value and protein efficiency ratio of SP were 98.72， 95.91 and 3.90， respectively， which were significantly higher than those of WP. The SDS-PAGE result indicated that WP was more digestible by pepsin than SP. After being heated with eel muscle oil， the free amino acids in the in vitro digested products of WP and SP increased significantly， while the digestion of casein were inhibited. Based on the present result， it is concluded that the nutritional value of SP in the European eel muscle is higher than that of WP， and heating treatment can promote the digestion of WP and SP.

Abstract:The differences of quality indexes (physical and chemical indexes， food and taste indexes and rice texture indexes) among 11 rice varieties were studied in this paper. The quality of different rice varieties was evaluated by principal component analysis and classified by cluster analysis. The results showed that the influence of rice varieties on viscosity and hardness quality indexes was greater， but the influence on water content and total starch content was small. The three principal components determined by principal component analysis can replace the above quality indexes to evaluate the quality of different rice varieties. Principal component 1 mainly integrated the food and taste value and sensory evaluation， principal component 2 mainly integrated the comprehensive score and appearance， and principal component 3 mainly integrated the amylose content and the ratio of amylose content to amylopectin content. Cluster analysis showed that Category I includes Suxiu 867， Daohuaxiang， Jinheyuanli， Huaidao 5 and Suijing 18， they had the best quality， Category II includes Huai 119， Nanjing 5505， Taoyouxiangzhan， Yangjing 3012 and Wuyunjing 32， with the quality in the middle. Category Ⅲ is Wuyou 61. This conclusion can provide some reference basis for the selection of high quality rice varieties.

Abstract:Water-in-water (W/W) emulsion is a new type of colloidal dispersion system， which has become a research focus of colloid and interface science. In this article， we review the parameters affecting the W/W emulsion formation and the properties of W/W emulsions， and summarize the typical W/W emulsions with natural macromolecules as matrix. Then， the stabilization of W/W emulsion using particles， block polymers and polyelectrolytes was introduced. Particularly， the stabilization mechanism and the parameters affecting the stabilization of W/W emulsion with particles were emphasized. The applications of W/W emulsion in the delivery of bioactives and starch digestion are also introduced. Finally， the research direction of W/W emulsions is proposed， such as the development of more food-grade systems of W/W emulsion for the food applications.

Abstract:The mechanism of glow discharge plasma on starch etching， oxidation， crosslinking and depolymerization was reviewed； The effect of technical parameters of glow discharge plasma， including the effects of gas type， generation mode， treatment power and treatment time on the structure and properties of starch was summarized. In this paper， the granular structure， crystal type， layered structure and the proportion of amylose and amylopectin of starch are summarized as structural changes， while the gelatinization property， rheology， enthalpy and heat change， acidity and solubility of starch are summarized as physical and chemical property changes. Finally， the applications of glow discharge plasma treated starch in the fields of food， packaging and materials industry were summarized， and the research directions and scientific problems to be solved in the future were prospected， which pointed out the research direction for the further research of glow discharge plasma in the field of starch in the future.

Abstract:Bacterial toxins that cannot be broken down or destroyed in a short period of time at 100 ℃ are generally considered heat-resistant. Because bacterial heat-resistant toxins have certain thermal stability， even if the bacteria are killed， there will still be a part of the toxin is not inactivated， causing great harm to food safety. This paper reviews the production and influencing factors of bacterial heat-resistant toxins in food， systematically analyzes their pathogenicity and mechanism of action， and concrete suggestions on reducing or avoiding the threat of these toxins to human health were put forward. This review is expected to provide theoretical basis for food safety risk assessment and new ideas for clinical treatment.

Abstract:Flavonoids are a class of natural bioactive substances that are widely present in vegetables and fruits that have a promoting effect on human health. Gut microbiota has been shown to play an important regulatory role in maintaining human health. Disturbance of gut microbiota increases the risk of many chronic diseases， such like inflammatory bowel disease， obesity， and colorectal cancer. This article systematically reviews the updated research progress of the interaction between dietary flavonoids and gut microbiota. On the one hand， dietary flavonoids can exert their biological activities by increasing the diversity of gut microbiota， promoting the growth of probiotics， inhibiting the reproduction of pathogenic bacteria and promoting the production of some beneficial metabolites such as short-chain fatty acids. On the other hand， the gut microbiota greatly influences the biotransformation and metabolic patterns of the dietary flavonoids. By producing the small molecule bioactive metabolites mediated by gut microbiota and improving the bioavailability， the gut microbiota partially determines the biological activity of dietary flavonoids in the body.

Abstract:Soybean lipophilins are the major components of soybean proteins isolated (SPI) except β-conglycinin (7S) and glycinin (11S). Lipoproteins are composed of phospholipid protein complexes and phospholipid free protein molecules. Under different temperature， SPI is highly similar to latrophilins on solubilization. Thus， soybean latrophilins can solve the problem of SPI functional deficiencies. Soybean latrophilins could lower the content of cholesterol and triacylglycerol. Plant polyphenols are a class of sub-metabolites with a polyol structure that can be found widely in plants， and phenolic compounds are considered as natural antioxidants that can prevent or delay oxidative damage caused by reactive oxygen species. The interaction of soybean lipophilins with polyphenols could modify the structural， functional， and nutritional properties of themselves and results in new complexes. This review summarizes the respective properties of soybean lipophilins and polyphenols， the mechanism of soybean lipophilin polyphenol interactions， and the functions of lipophilin polyphenol complexes to provide a theoretical basis for the complexation， utilization， and applications of soybean lipophilins and plant polyphenols in more food products.

Abstract:The imbalance between energy intake and energy consumption leads to the increase of adipose tissue and the disorder of lipid metabolism， which leads to obesity， diabetes， cardiovascular disease and other metabolic diseases. Resveratrol (RSV) is a natural astragalus polyphenols compound， which can effectively improve obesity and other metabolic diseases by regulating lipid synthesis and oxidative decomposition， adipokine secretion， adipose tissue heat production and inhibiting inflammation. At present， the regulation of lipid metabolism by RSV has attracted extensive attention and made great progress. Therefore， this paper reviews the recent studies on the regulation of lipid metabolism by RSV， in order to provide more theoretical basis for the application of RSV in improving metabolic diseases.

Abstract:Neurodegenerative diseases are the pathological basis of cognitive function degradation and nervous system diseases， which are affected by many internal and external environmental factors. Microbes living in the gut can affect health and the occurrence and progress of many diseases， including nervous and mental diseases. Intestinal disorders are closely related to cognitive and motor dysfunction diseases， such as Alzheimer's disease， Parkinson's disease， Huntington's disease and multiple sclerosis and so on. It was found that dietary intervention can improve the relationship between gut and brain， regulate the advanced brain functions such as cognition and emotion， alleviate cognitive decline and inhibit neurodegenerative diseases. But the internal mechanism is not clear， which may be related to dietary intervention regulating the composition and function of gut microbiota， thereby improving intestinal metabolism， intestinal endocrine and other mechanisms. This paper analyzes the relationship between dietary intervention and the regulation of gut microbiota and related physiological and biochemical changes， brain cognition and neural function， and discusses the role and possible mechanism of dietary intervention in gut microbiota， gut brain connections and neurodegenerative diseases.

Abstract:Biological speckle technology is an efficient and economical non-destructive testing technology that can describe the biologically active area of the tested item by measuring the change of light interference. The speckle activity reflects the state of the surface and internal tissue of the tested item， and can provide real-time qualitative or quantitative information about the tested item. This article introduces the basic principles of biological speckle technology and speckle image analysis methods， reviews the application progress of biological speckle technology in the food field， and prospects the application of the technology in the future.

Abstract:The research on the detection methods of food bacterial contamination is of great significance to reduce the outbreak of food borne diseases and food corruption. Metal organic frameworks (MOFs) are highly ordered crystal coordination polymers formed by metal ions or metal ion clusters and multiple organic ligands via coordination bonds. A variety of sensor detection systems including fluorescent sensor， colorimetric sensor， electrochemical sensor and so on have been constructed based on MOFs due to its unique structure and characteristics. This paper mainly introduces the types and components of MOFs-based sensors， as well as the research progress of detection methods of food bacterial contamination based on MOFs sensors. The limitations and future development direction of detection methods of MOFs sensors are also prospected.

Abstract:Food pollution and corruption caused by microorganisms are two major problems facing the global food industry， and also the focus of governments on food quality and safety and food supply security. Accurate and rapid monitoring of microbial contamination in food is of great significance to reduce food waste and foodborne disease outbreaks. Molecularly imprinted polymers(MIPs) have been widely used in the detection of food spoilage bacteria and pathogenic microorganisms due to their easy preparation， high specificity and stable performance. In this paper， the synthetic methods of microbial molecularly imprinted polymers， including emulsion polymerization， electrochemical polymerization and microcontact imprinting method， are reviewed. The research achievements of MIPs-based detection methods， such as fluorescence， electrochemical sensors， surface plasmon resonance， quartz crystal microbalance， and resonance light scattering， are introduced in the detection of food spoilage bacteria and pathogenic microorganisms. The application prospect and development direction of this technology are also prospected.

Abstract:Understanding the awareness of family food safety knowledge of children's parents in China and its influencing factors is of positive significance to carry out accurate food safety education and reduce family foodborne diseases. Therefore， this study conducted a questionnaire survey among 13 923 parents of children aged 3-12 in 7 cities to collect basic information， household food safety knowledge and needs. The average score of parents on family food safety knowledge was 18.6 points (out of 29 points)， and the pass rate was 68.7%. The main mistakes included food storage and food poisoning. Multivariate logistic regression analysis shows that the pass rate of parents' family food safety knowledge was affected by region， education level， occupation， relations with children， paying attention to food safety or not， getting related information from their child or not. The top three contents that parents were concerned about were abuse of food additives (84.9%)， poor hygiene (82.9%) and pesticide/drug residues (82.7%). The main sources of information trusted by parents were TV/radio/advertisement (76.1%)， books/newspapers/periodicals (70.4%)， weibo/wechat and other new media (57.7%). The level of parents on family food safety is low. It is necessary to carry out dissemination through the combination of traditional media and new media and the form of small hands holding big hands， and pay special attention to parents with low education level and engaged in the food industry， as well as children's fathers and nannies.