Abstract:‘Healthy China 2030’ has become a national strategy， and the development of the food and nutrition health industry holds significant importance in improving the overall nutritional health of the population. The nutritional functionality of food in the human body largely depends on its process of digestion and the resulting products. Due to ethical restrictions on human research， in vitro simulation of human gastrointestinal digestion and fermentation has become a crucial technical issue for food nutrition research. This achievement combines the principles of human gastrointestinal digestion and fermentation， comprehensive simulation， and artificial intelligence. It establishes the basis for the construction of the simulation device based on the physiological characteristics of the human gastrointestinal environment from the oral cavity to the stomach， small intestine， and large intestine. It has independently designed and completed core simulation components such as digestion/fermentation tanks， gastrointestinal emptying devices， digestive fluid secretion devices， absorption devices， and established key simulation technology for gastrointestinal digestion， fermentation， and absorption. It has also constructed an AI intelligent system for simulating， sampling， monitoring， and warning any part of the gastrointestinal tract， combined with centralized control devices to achieve automatic simulation of the digestion， fermentation， and absorption process， breaking through the bottleneck of intelligent control technology. Based on the aforementioned key technologies， it has achieved the full process simulation of oral cavity - stomach - small intestine - large intestine， and can systematically verify animal or clinical trial results. With the device， an evaluation technical system for gastrointestinal digestion and metabolism of different food nutrients was established， uncovering various modes of digestion and metabolism for different food nutrients， and facilitating the formulation of optimized products. This contributed to the development and industrialization of a series of new health products， in support of the national strategy of‘Healthy China 2030’， and was selected as one of the Top Ten Advances in Chinese Food Science and Technology in 2022.

Abstract:Abnormal methylation of RNA m6A is an important cause of the occurrence and development of many metabolic diseases， and flavonoids have the effects of preventing metabolic diseases， but the mechanism of action is not clear. In this study， unlabeled biomolecular interaction techniques were performed to investigate the interactions between the three common flavonoids (curcumin， fisetin and galangin) and demethylase FTO， and molecular docking technique was further used to reveal the mechanism of the interactions. The effect of the interaction of flavonoids with FTO on RNA m6A demethylation was investigated using an in vitro cell model of low-grade inflammation. The results showed that curcumin， fisetin and galangin could significantly quench the fluorescence of FTO protein， and increased the resistance to protease hydrolysis and thermal stability of FTO， suggesting that all the three flavonoids can directly bind to FTO. Molecular docking results showed that these three flavonoids bound to the catalytic cavity of FTO protein， and the key amino acid binding sites included Arg96， His231， His232， Asp233， His307， and Arg322， thus potentially activating the demethylation activity of FTO. Furthermore， in vitro low-grade inflammation led to an increase in intracellular RNA m6A methylation， and the direct binding of curcumin， fisetin and galangin to FTO， inhibited the inflammation-induced increase in RNA m6A methylation， of which curcumin had the most obvious effect. The results of this study provide a theoretical basis for FTO as a novel target of flavonoids in the prevention of metabolic diseases.

Abstract:Phytosterols have received an extensive attention owing to their excellent cholesterol-lowering activity and the role in cardiovascular diseases prevention. Phytosterol diacid monoesters， the important intermediates in the structural modification of free phytosterols， were often obtained by chemical method with catalyst. The aim of this research was to provide a synthesis technology of phytosterol adipate monoesters and explore the possible mechanism on reducing cholesterol level in vitro. β-Sitosterol vinyl adipate was hydrolyzed to β-sitosterol adipate monester in the presence of Lipozyme TL IM and tert-butanol， and the maximum hydrolysis rate was more than 99%. Compared with free β-sitosterol， β-sitosterol adipate monester possessed lower crystallinity and improved wetting properties. The contact angle was decreased from 131.4° to 98.6°. That was beneficial to dissolve in model cholesterol mixed micelles and swell micellar hydrophobic core. The microstructure of micellar and precipitation phase was observed and found further that β-sitosterol adipate monester kept the cholesterol-lowering activity in vitro due to its precipitation effect on model mixed micelles. This study has certain social value and practical significance to develop phytosterol dietary nutritional supplement.

Abstract:This work aimed to investigate the non-covalent interaction between lotus root polysaccharide (LRP) and ferulic acid (FA)， as well as the physicochemical and functional properties of LRP-FA complex. Based on single factor experiment and response surface experiment using the FA binding amount as evaluation index， the preparation conditions of LRP-FA complex were optimized. The results showed that， after 30 min low-speed mixing at temperature 0 ℃ and pH 7 with the FA-LRP mass ratio of 1∶2， the binding amount of FA to LRP was 110.22 mg/g. The interaction increased the average molecular weight of LRP from 191.8 ku to 297.4 ku. According to the effect of experimental factors on the FA binding amount and the spectral analysis of LRP-FA complex， it was found that the non-covalent interaction between LRP and FA mainly depended on hydrogen bonding. Low temperature was beneficial to maintain the stability of LRP-FA complex， and its FA dissociation rate was lower than 25% by the simulated digestion of mouth， stomach and small intestine. Tthe complex had a better DPPH free radical scavenging activity compared with LRP (P<0.05)， however， their stimulating abilities on the NO production of macrophages showed no significant difference (P>0.05). The results provide ideas for improving the functional activity of LRP and the bioavailability of FA.

Abstract:Objective: To study the protective effect of zeaxanthin on endoplasmic reticulum stress-induced apoptosis. The research was divided into blank control group， TM injury group (5 μg/mL)， zeaxanthin protection group (5 μmol/L) and injury plus protection group. The Caspase 3 activity detection kit is used for detecting changes of Caspase 3 enzyme activity. The apoptosis-related proteins PERK and CHOP， the downstream signal molecules elF2α and ATF4 of PERK， and the autophagy-related protein Beclin 1 were determined by Western Blot. The results showed that compared with the TM model group， the expressions of PERK and its downstream regulatory proteins elF2α and ATF4 after zeaxanthin treatment were significantly decreased (P<0.01)， and the level of Beclin 1 was significantly increased (P<0.01). The level of GRP78 in the zeaxanthin group was significantly higher than that in the absence of 3MA autophagy inhibitor (P<0.01). Compared with the control group， the CHOP protein expression level in the TM model group was significantly increased (P<0.01)， while the CHOP protein expression level in the zeaxanthin treatment group was significantly lower than that in the TM model group (P<0.01). Conclusion: Zeaxanthin can reduce the damage caused by endoplasmic reticulum stress and reverse the damage caused by TM to a certain extent. The mechanism is that by inhibiting the PERK pathway and further inhibiting the separation of GRP78 and ERS receptors， the level of pro-apoptotic factor CHOP is reduced， and alleviate ERS by regulating protective autophagy.

Abstract:Objective: In this study， the fermentation and storage characteristics of probiotic fermented milk (PFM) were evaluated. Methods: Bifidobacterium animalis subsp. V9 (Bifidobacterium animalis subsp. V9)， Lacticaseibacillus paracasei PC-01 (Lacticaseibacillus paracasei PC-01)， and Lactiplantibacillus plantarum P-8 (Lactiplantibacillus plantarum P-8) were mixed fermented with control group compared (containing Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus). Optical microrheometer was used to monitor the rheological parameters during fermentation， the content of free amino acids at fermentation termination， the viable cell count， titrable acidity (TA)， and other physical and chemical indexes during storage. Result: The fermented milk of probiotics showed high viscosity factor， high solid-liquid equilibrium value， low elasticity factor， and low flow state. Fourteen kinds of free amino acids were detected at the end of fermentation， among which eight kinds of amino acids were significantly increased， content of phenylalanine (0.93 mg/kg)， valine (3.3 mg/kg)， alanine (22.6 mg/kg)， lysine (12.6 mg/kg)， threonine (3.8 mg/kg)， serine (3.5 mg/kg)， proline (35.4 mg/kg) and leucine (5.4 mg/kg). The viable cell counts of Lactobacillus and V9 in PFM group was 2.34×108 CFU/mL at storage initial and 3.43×107 CFU/mL at the end of storage (28 d)， respectively. Compared with the control group (FM)， there were no significant differences in pH value， TA， and water holding capacity， and the viscosity was significantly reduced (P＜0.01)， and sensory taste score was significantly increased (P＜0.05). Conclusion: The PFM group has excellent fermentation and storage characteristics， which can provide data support and theoretical basis for the industrial production of probiotic fermented dairy products.

Abstract:Objective: In the simulated system， bacteriostatic agents and their active ingredients can exert a good inhibitory effect when in direct contact with the bacteria. However， when added to complex food systems， the inhibitory effect is less than that in the simulated environment. The purpose of this study was to explore which components in the complex meat system affect the antibacterial activities of nisin and carvacrol， and to determine the effect. Methods: AGAR diffusion method was used to determine the diameter of antibacterial zone and broth dilution method was used to determine the total number of bacteria to explore the effects of meat components on the antibacterial activities of nisin and carvacrol， respectively. Results: Both water-soluble myoglobin and water-insoluble myofibrillar protein had adverse effects on the antibacterial activities of nisin and carvacrol. Linoleic acid also had a certain inhibitory effect on nisin and carvacrol. However， various free amino acids and glycogen had no significant effect. Conclusion: Higher concentrations of protein and fat components have negative effects on the antibacterial activities of nisin and carvacrol， while various free amino acids and glycogen have almost no effects.

Abstract:Rhodococcus sp. 11-3 is a high-yielding chitin deacetylase (CDA) strain. The enzyme catalyzes chitin to produce chitosan， which plays an important role in the green production of chitosan. However， the CDA produced by Rhodococcus sp. 11-3 is an intracellular enzyme， which has become a major obstacle to the catalytic reaction. In order to improve the release efficiency of CDA， different physical methods (repeated freezing and thawing， ultrasounding， ball milling， homogenization and liquid nitrogen grinding)， chemical methods (surfactants treatment， chloroform treatment) and biological method (lysozyme treatment) were used to disrupt the cell wall of Rhodococcus sp. 11-3. The enzyme activity and release efficiency of CDA were determined， and the changes of cell morphology was observed by scanning electron microscope. The results showed that different methods had very different effects on the cell wall breaking. Among them， liquid nitrogen grinding was the best method. By using it， there were fine holes on the cell surface， the release efficiency of CDA was 45.13%， and the loss rate of total enzyme activity was 2.03%. Homogenization was next only to liquid nitrogen grinding， the release efficiency of CDA was 16.00%， and the loss rate of total enzyme activity was 9.18%. Then， Rhodococcus sp. 11-3 cell was treated with homogenization and liquid nitrogen grinding in succession. The results showed that more and larger pores were produced on the cell surface， the release efficiency of CDA was up to 86.17%， the loss rate of total enzyme activity was 9.11%， and the CDA activity in the supernatant was 480.2 U/mL， which was 1.48 times higher than that of liquid nitrogen grinding. Therefore， the combined treatment of homogenization and liquid nitrogen grinding could effectively disrupt the cell wall of Rhodococcus sp. 11-3 and improve the release efficiency of intracellular CDA. The results would promote the application of Rhodococcus sp. 11-3 CDA in the production of chitosan.

Abstract:The glass temperature (Tg) and melting temperature (Tm) of ethyl cellulose (EC) and cooling methods of oleogels which effected on the mechanical properties and oxidation characteristics of the gel were studied. Meanwhile， the relationship between hydrogen bonding and oxidative stability of EC oleogels were described. The results showed that the oleogels prepared at the glass temperature (135 ℃) and melting temperature (187 ℃) of EC (EC with viscosity of 40~50 mPa·s) all had solid-like behavior. Compared with Tg， the storage modulus and texture properties of samples prepared at Tm were higher. After stored at 25 ℃ for 30 days， the headspace oxygen consumption of the Tm sample was 0.71%. Polarization microscope and scanning electron microscope showed that EC could be better dissolved in the oil phase when oleogels prepared at Tm， and the gel network structure was more compact. The pore diameter of the oil droplets was 38.56% of the Tg. Fourier transform infrared spectroscopy showed that the hydroxyl stretching vibration peaks of EC oleogels prepared at Tg and Tm shifted from 3 472.48 cm-1 to 3 468.48 cm-1， which implied the hydrogen bond effect was enhanced. With the addition of EC from 4% to 10%， the headspace oxygen consumption decreased with the increase of the addition of EC. Compared with the fast cooling sample of 10%EC， the headspace oxygen consumption of the slow cooling sample was only 64.67% of it， and the hydroxyl stretching vibration peak shifted from 3 499.74 cm-1 to 3 471.78 cm-1 which showed the hydrogen bond effect was enhanced. The results showed that the enhancement of the hydrogen bonding during the preparation of EC oleogels formed a denser liquid crystal network structure and reduced the oxidation rate of the oleogels.

Abstract:The effects of different concentrations of gallic acid (0， 1， 2， 4， 6 mg/g) with the aid of ultrasound on the structural properties of myofibrillar proteins of Lateolabrax japonicas were investigated. The structure and gel information through Raman spectroscopy， endogenous fluorescence spectroscopy， surface hydrophobicity， differential calorimetric scanning (DSC)， dynamic rheology， molecular mass were analyzed. The results showed that ultrasound and gallic acid addition could change the secondary structure of myogenic fibronectin in Lateolabrax japonicas. The α-helix content of myogenic fibrillar protein increased from 52.81% to 74.68% and β-folding decreased from 21.3% to 5%. When the addition of gallic acid increased from 0 mg/g to 2 mg/g without ultrasound treatment， the β-turn and irregular curl content decreased； when the gallic acid content continued to increase， the α-helix content showed a decreasing trend. After ultrasonic treatment， the α-helix content increased further， and the highest α-helix content reached 80%， when the gallic acid was added at 2 mg/g. Meanwhile， with the increase of gallic acid， the tertiary structure and gel properties of proteins were changed， the fluorescence intensity was decreased， but the surface hydrophobicity was significantly increased (P < 0.05). In addition， the thermal denaturation temperature of myofibrillar proteins， and the enthalpy change and rheological properties were also increased， which showed that ultrasound-assisted gallic acid could change the structure of proteins， thus promoting the formation of more viscoelastic gels of myofibrillar proteins. The protein structure was changed by ultrasound-assisted gallic acid， thus promoting the formation of a more viscoelastic gel network structure， which led to the improvement of protein gel properties.

Abstract:Objective: Taking the rice protein hydrolysates/wheat starch complexes as the object to study the effects of high pressure processing (HPP) on its physicochemical properties and digestibility in vitro， and to explore its change mechanism. Methods: The effects of HPP on the physical and chemical properties of the complexes， such as crystallinity， gelatinization properties， water distribution and rheological properties were analyzed. The effect of HPP on the in vitro digestion characteristics of complexes was analyzed. Results: The order of molecules in the system was increased and the co-crystallization was more extensive under 350 MPa pressure. After HPP， the relaxation time of the complexes was shortened， the water fluidity was weakened， the gelatinization time was delayed， the peak viscosity was significantly reduced， and the viscoelasticity was improved. The digestibility of the complexes was reduced under 350 MPa pressure conditions because HPP promoted the infiltration of RPH into the starch and its distribution was more uniform. Conclusion: HPP can enhance the interaction between starch and protein in the complexes system， and has the potential to further reduce its in vitro digestibility.

Abstract:In order to improve the nutritional value of metric staple food， rice flour and potato snowflake whole powder were mixed according to different proportions. The microstructure， chemical structure， crystal structure， particle size， gelatinization property， thermal stability and rheological properties of the powder were analyzed and studied by means of scanning electron microscope， infrared spectrometer， X-ray diffractometer， particle size analyzer， viscometer， differential thermal analyzer， rheometer and texture analyzer. The results showed that the surface of rice flour and potato snowflake powder was smoother than that of potato flour. The surface of potato flour was damaged in the process of production， so the surface of rice flour looked irregular and rough. The infrared spectral peak position of different proportions of mixed powder was basically the same， and the structure of functional groups did not change significantly. The crystal structure of rice flour and potato flour both belong to A-type crystal， and the crystallinity of mixed flour increases with the increase of the proportion of potato flour. The average particle size of rice flour was 82.35 μm， and that of potato whole meal was 280.8 μm. With the increase of the proportion of potato whole meal， the average particle size of mixed meal increased. With the increase of the total flour proportion， the gelatinization temperature and gelatinization enthalpy， the energy storage modulus and energy dissipation modulus， the solubility and swelling degree， the resilience， cohesion， viscosity， decay value and recovery value， the hardness， elasticity and chewability of the potato decreased， and the freeze-thaw stability decreased. The mixing ratio of rice flour and potato flour has a significant effect on the grain structure and physicochemical properties of the mixed flour， which provides reference data for the development of mixed rice staple food.

Abstract:Objective: The hepatoprotective effect of bound phenolics from Lycopus lucidus Turcz. was investigated using an in vitro CCl4-induced hepatocyte damage model. Methods: The cell viability was determined by MTT method and the levels of ALT， AST and LDH were determined using a clinical automatic biochemical analyzer. The levels of MDA， SOD， GSH， TNF-α， IL-6， IL-8 and the activation of Caspase-3 were measured by kits. Meanwhile， apoptosis was determined by flow cytometry and the change of mitochondrial membrane potential was detected using a mitochondrial membrane potential assay kit with JC-1. Correlation analysis was carried out by Pearson correlation program. Results: The results showed that no cytotoxicity was found of the bound phenolics from Lycopus lucidus Turcz. within the tested dose range (0.2~1.6 mg/mL). The bound phenolics inhibited the CCl4-induced reduction of cell viability， SOD and GSH. Meanwhile， the bound phenolics pretreatment reduced the CCl4 -induced elevation of MDA， ALT， AST， LDH， TNF-α， IL-6， IL-8 and Caspase-3 activation. Moreover， the bound phenolics pretreatment significantly improved the apoptosis and the decrease of mitochondrial membrane potential caused by CCl4. The results of the correlation analysis showed a significant positive correlation was observed between ALT， Caspase-3， TNF-， IL-6， and IL-8， and a significant negative correlation was found between GSH and SOD and ALT， Caspase-3， TNF-， IL-6， and IL-8. Conclusions: The bound phenolics from Lycopus lucidus Turcz. exerted a protective effect against CCl4-damaged hepatocytes through antioxidation， inhibition of inflammatory response and apoptosis and protection of mitochondria.

Abstract:In order to explore the effects of different factors on the characteristics of Dendrobium officinale polysaccharide gel， the effects of polysaccharide concentration， gelation temperature， alkali and ion on the characteristics， water retention， acetyl group content of Dendrobium officinale polysaccharide gel were studied. The properties of polysaccharide were characterized by differential scanning calorimetry (DSC)， Fourier infrared spectroscopy (FTIR) and diffractometer (XRD). The results showed that when the mass concentration of polysaccharide increased from 5 mg/mL to 25 mg/mL， its gel strength increased from 70.87 g to 206.39 g， and its water holding capacity increased from 78.52% to 94.25%. When the temperature reached 40 ℃， the maximum strength of gel was 129.29 g， and the corresponding water holding capacity was 90.58%. With the increase of the mass concentration of different alkalis (NaOH， Na2CO3， KOH， K2CO3)， the strength of gel continuously increased at first and then decreased， and the water holding capacity of gel gradually decreased. Under the condition of the same amount of alkali addition， the strength of gel formed was in the order of Na2CO3>K2CO3>NaOH>KOH. In terms of electrolyte， sodium ion could improve the strength and water retention of gel， while urea could significantly reduce the strength and water retention of gel. FTIR spectra showed that the absorption peak intensity of acetyl group group decreased with the increase of Na2CO3 addition. The degree of deacetylation of polysaccharides was related to their alkali content. The XRD results indicated that the diffraction peak intensity was related to the amount of alkali added， and the higher the amount of alkali added， the stronger the diffraction peak. The DSC results indicated that as the amount of alkali increases， the peak temperature of the water absorption peak increases， and the enthalpy value of the peak increases. The mechanism of gel formation may be related to the hydrolysis of acetyl group group promoting the interaction between polysaccharide molecules.

Abstract:The antimicrobial activity and DNA binding mechanism of a novel antimicrobial peptide (AMP) PV13 against Vibrio parahaemolyticus from Penaeus vannamei were explored. The sequence of the peptides were identified by using ultra-high-performance liquid chromatography-high resolution mass spectrometry， and the cationic antimicrobial peptide PV13 (ALPWVLPWALPRALPRVLPR) was screened by using in silico tools. The antimicrobial activity of AMP PV13 against V. parahaemolyticus was evaluated by minimum inhibitory concentration (MIC) and time-kill curve， the MIC of PV13 was 62.5 μg/mL and killed V. parahaemolyticus within 2 h. The antibacterial mechanism of PV13 against V. parahaemolyticus was evaluated using transmission electron microscopy (TEM)， intracellular membrane permeability， DNA gel retardation and circular dichroism. The results shows that PV13 increases bacterial cell membrane permeability and binds bacteria genomic DNA concentration dependently. Moreover， AMP PV13 exhibited a random coil structure in PBS and SDS solutions， while its structure changed significantly after binding with DNA of V. parahaemolyticus. The antimicrobial activity of peptide PV13 could be due to the presence of four leucine-proline repeat regions. The above results provide new insight into screening and designing AMPs from P. vannamei， and offer a theoretical basis of AMP PV13 for their potential applications in food preservation.

Abstract:AI-2 signal molecule could regulate the biofilm formation and probiotic property of lactic acid bacteria (LAB). In this study， the strain with high production AI-2 were screened from 16 strain lactic acid bacteria derived from traditional fermented food and carp intestines. The ability of biofilm formation， antioxidant and aroma-producing of high production AI-2 LAB were analyzed. The results showed that the relative fluorescence intensity of the high production AI-2 strain DBM2-4 was 9.69. The strain DBM2-4 was identified as Lactiplantibacillus plantarum by physiological and biochemical and 16S rRNA sequencing analysis. Compared with the low production AI-2 strain YF-7， strain DBM2-4 was cultured at 37 ℃ for 24， 48 h， and 72 h， the production of biofilm formation increased by 85.48%， 135.54%， 63.03%， respectively. Meanwhile， the free radical scavenging capacity of DPPH for complete cell and cell-free extracts of strain CY1-2 increased by 24.49% and 11.37%. The production of diacetyl and acetaldehyde increased by 3.42 mg/L and 5.86 mg/L， respectively. These results indicated that AI-2 signal molecule regulated the biofilm formation， antioxidant activity and aroma-producing activity of Lactiplantibacillus plantarum DBM2-4， The screening of LAB with high production of AI-2 would provide a theoretical basis for improving the probiotic， antioxidant and aroma-producing activity of LAB starters.

Abstract:To explore the bacterial strains suitable for fermented meat products， Xinyang Bacon， Sichuan Bacon， Yunnan Bacon and Hunan Bacon were used as materials， based on the safety， production adaptability and fermentation performance of the strain， the species of bacteria in naturally fermented bacon were determined through isolation， screening， 16S rDNA sequencing and basic fermentation characteristics， and the suitability of each strain as a starter. The results showed that 5 strains with high salt tolerance， nitrite tolerance， acid tolerance and excellent fermentation performance were isolated and identified， Streptococcus lactis， Staphylococcus saprophyticus， Staphylococcus xyloides， Staphylococcus equi and Leuconostoc enteritidis. The 5 strains screened are expected to be used as fermentation strains in bacon production.

Abstract:The effects of sugar beet pectin (SBP) on the short-term and long-term retrogradation of wheat starch were investigated by rheological analysis， texture analysis， Fourier transform infrared spectroscopy， X-ray diffraction and scanning electron microscopy， respectively. The results showed that with increasing of SBP concentrations， the peak viscosity， final viscosity and relative breakdown viscosity of wheat starch significantly increased (P<0.05)， while relative setback viscosity remarkably decreased (P<0.05). SBP reduced the sedimentation rate， and the volume fraction of supernatant after 48 hours of standing decreased from 76.03% to 6.01%. After adding SBP， the increment of starch gel hardness during storage significantly decreased from 356.02 to 178.19 g (P<0.05)， the ratio of 1 047 cm-1/1 022 cm-1 decreased from 0.72 to 0.61， and the relative crystallinity decreased from 10.11% to 8.06%. Moreover， scanning electron microscopy results showed that the higher addition of SBP could reduce the surface roughness of starch gel and maintain honeycomb structure after retrogradation. These results demonstrate that the addition of SBP plays a crucial role in interfering with retrogradation of wheat starch. Adding appropriate amount of SBP can reduce the retrogradation degree of starch based food during processing.

Abstract:Objective: To investigate the improvement effect of chestnut shells pigment (CSP) on lipid metabolism disorder in obese mice and its molecular mechanism. Methods: Male C57BL/6J mice were divided into normal diet group (N)， high fat diet group (HFD)， high fat diet +20 mg/kg CSP group (HFD-L)， high fat diet +50 mg/kg CSP group (HFD-H)， high fat diet +20 mg/kg catechin group (HFD-C). The body weight and food intake of mice were measured every week. After 14 weeks， the weight of liver and epididymis fat of mice and lipid levels of serum were detected. The morphology of fat and liver was analyzed and the expression of key proteins of fat metabolism in liver was detected. Results: Compared with HFD group， the gain of body mass in HFD-L and HFD-H groups decreased by 28.67% and 39.16%， respectively. Fat mass of epididymis decreased by 23.63% and 42.80%， respectively. CSP can reduced food intake and accumulation of liver fat， reduced serum TG， TC， LDL-C， ALT and AST levels， increased HDL-C. The expression levels of p-AMPK/AMPK， p-ACC/ACC and PPARα in liver tissue were significantly increased， however， the expression levels of SREBP-1C and HMGCR were significantly decreased， which were better than those of pure catechin. Conclusion: CSP can improve lipid metabolism in obese mice， which is related to the activation of AMPK signaling pathway.

Abstract:Purpose: To investigate the alleviating effects of three grapefruit peel pectins extracted by alkali (P10)， cellulase (C)， and alkali + cellulase (P10+C)， on dextran sodium sulfate-induced acute colitis of the mice. Methods: The mice were randomly divided into normal group， model group， P10 group， C group and P10+C group. The changes of tissue structure， inflammatory factors， gut microbiota and short-chain fatty acids were analyzed by staining， ELISA， 16S sequencing and gas chromatography， respectively. Results: The alleviating effects were most significant for P10+C， followed by P10 and C. P10+C significantly reduced disease activity index and spleen hypertrophy in DSS induced colitis mice， alleviated colon shortening and redness， colonic mucosa damage， crypt destruction and goblet cell reduction， and effectively protected the intestinal barrier. P10+C significantly increased the levels of anti-inflammatory cytokines (IL-10) and inhibited the secretion of pro-inflammatory cytokines (IL-6， IL-1β， TNF-α). Meanwhile， P10+C improved the richness and diversity of gut microbiota of colitis mice， increased the relative abundance of beneficial bacteria Akkermansia， Clostridium_sensu_stricto_1， Lachnospiraceae_NK4A136_group， Lactobacillus， and Ruminococcaceae_UCG-014， and promoted the production of short chain fatty acids， thus alleviating intestinal inflammation. Conclusion: P10+C can be used as a potential prebiotic to alleviate acute colitis.

Abstract:Objective: This experiment was conducted to investigate the hypoglycemic effect of polyphenol extract from germinated mung bean on type 2 diabetic mice and the effect on intestinal flora of mice. Methods: According to the weight of C57BL/6 mice， they were randomly divided into normal group， T2DM model group， positive control group， and low (50 mg/kg)， medium (100 mg/kg) and high (150 mg/kg) dose group of germinated mung bean polyphenols extract. A model of type 2 diabetic mice was established by high fat diet combined with intraperitoneal injection of streptozotocin (STZ). After 5 weeks of intragastric administration， fasting blood glucose (FBG)， glucose tolerance， insulin (INS)， and the concentrations of inflammatory cytokines interleukin IL-6， IL-10， tumor necrosis factor (TNF-α) and C-reactive protein (CRP) were determined. The feces of mice were collected. The 16S rRNA platform was used to carry out high-throughput sequencing to detect the changes of intestinal flora in diabetic mice under the intervention of polyphenol extract. Results: Germinated mung bean polyphenol extract could significantly reduce fasting blood glucose， improve glucose tolerance and reduce insulin resistance in T2DM mice. The levels of IL-6， TNF-α and CPR were significantly decreased， and the levels of IL-10 were increased， thus alleviating the inflammatory response caused by diabetes. Repair mouse liver tissue cell morphology. Regulate flora abundance and species diversity to improve the dysfunctional intestinal flora. Conclusion: The polyphenol extract of germinated mung bean can improve the type 2 diabetes in mice by reducing the inflammatory response and regulating the abundance of intestinal flora.

Abstract:Highland barley， as a characteristic grain in the Qinghai Tibetan region of China with more abundant active substances compared with common crops. And the future development prospects of highland barley are considerable. In this study， three kinds of highland barley powder were selected for frying and processing. The purpose of this study was to explore the effects of different kinds of highland barley powder on anti-fatigue， hypoglycemia and anti-hypoxia in mice. Compared with the control group， the weight-bearing swimming time of mice in the black highland barley fried powder group was 1.9 times higher than that in the control group， and the blue highland barley fried powder group was 1.28 times higher than that in the control group. The anti-fatigue effect of highland barley fried powder was significantly improved (P<0.05)， and different kinds of highland barley could inhibit the contents of urea nitrogen (BUN) and creatine phosphokinase (CK) in mice. The results of normal pressure hypoxia tolerance test in mice showed that different kinds of highland barley powder and highland barley fried powder had no toxic effect on heart and brain tissue of mice. The level of HIF-1 in brain tissue of mice in yellow highland barley powder， blue highland barley powder， yellow highland barley fried powder and blue highland barley fried powder group was higher than that of the control group， which was more beneficial to the improvement of hypoxia tolerance of mice. In the hypoglycemic experiment of diabetic model mice， on the one hand， highland barley powder does not produce toxic effect， on the other hand， blue highland barley fried powder has a certain effect on the improvement of biochemical indexes such as TC， MDA， GHb and so on. This study provides a scientific basis for analyzing and comparing the efficacy evaluation of different varieties of highland barley， and also provides a new idea for the development of functional food for diabetic people and potential diseased people in plateau areas.

Abstract:Zunyi black tea (ZBT) is a kind of Congou black tea originating from Zunyi city of Guizhou province in China. Currently， there are few reports about the chemical compositions and bioactivity of ZBT. Herein， the characteristic chemical compositions and hypolipidemic activity of ZBT are explored for clarifying its quality characteristics. As a result， it was observed that the content of K (22 655.89 mg/kg) was the most abundant element in ZBT， and the contents of toxic elements including As， Cd， Cr and Pb were all below the limits. Alcohols were the main volatiles accounted for 56.49%， and volatiles with floral and fruity aroma were detected， such as linalool (36.58%) and geraniol (10.91%). The content of total amino acid in ZBT was 10 396.67 mg/kg. High levels of theanine， glutamate， aspartate， asparagine contributed to the umami taste were existed in ZBT. It was showed that no astringent and bitter tastes was detected in ZBT through using electronic tongue system. In addition， the hypolipidemic activity of ZBT was investigated by high-fat zebrafish model， and water extract of ZBT at 800 μg/mL significantly reduced lipid level by 54.98% of high-fat zebrafish (P < 0.05). Hence， the above results revealed the quality characteristics of ZBT and provided further insights into bioactivity of ZBT.

Abstract:In this paper， magnetic nanoparticles Fe3O4-SiO₂-HPG-COOH was prepared as immobilized carrier to covalently immobilize horseradish peroxidase (HRP)， and applied to the degradation of zearalenone (ZEN). The immobilized HRP was characterized by Fourier transform infrared spectroscopy， X-ray diffraction and scanning electron microscopy， which verified that HRP was successfully immobilized on the carrier. The prepared nanoscale carrier Fe3O4-SiO₂-HPG-COOH has uniform size and shape， good dispersion and strong magnetic properties. The saturation magnetization value was 25.80 emu/g， and the average particle size was 103.15 nm. Compared with free enzyme， the magnetically immobilized HRP indicated higher acid-base tolerance and thermal stability， the optimal pH value was increased from 6.5 to 7.0， the optimal temperature was increased from 30 ℃ to 35 ℃. Magnetic immobilized HRP was applied to ZEN degradation， and the relationship between solution pH， reaction temperature， hydrogen peroxide concentration and reaction time with ZEN degradation rate was investigated using single-factor experiments. The results showed that under the conditions of reaction temperature of 35 ℃， hydrogen peroxide concentration of solution 26 mmol/L， pH 7.0 and reaction time 480 min， the removal efficiency of ZEN was 68%. The immobilized HRP had good repeatability， and the relative enzyme activity remained above 79.85% after 5 cycles. This research shows that magnetic immobilized HRP has good degradation ability to ZEN.

Abstract:In this study， porous corn starch (PS) was prepared by compound modification of corn starch with α-amylase and glucoamylase， and the PS was modified by octenyl succinic anhydride(OSA). The optimum preparation conditions were investigated with oil absorption ratio and degree of substitution(DS)， and the absorbability and sustained-release properties of OSA-PS as curcumin microcapsule wall material were discussed. The results showed that the optimum preparation conditions of PS were as follows: enzyme dosage 3%， enzyme ratio 1∶5(g/g)， reaction time 10 h， reaction temperature 50 ℃， pH 6.0， under which the oil absorption ratio of PS was 139.37%. The optimum synthesis conditions of OSA-PS were as follows: substrate mass fraction 25%， pH 8.5， anhydride 3.5%， reaction time 4 h， reaction temperature 40 ℃. Under these conditions， the substitution degree of OSA-PS was 0.02026， and the oil absorption ratio was 120.05%. SEM results showed that the modified starch formed obvious pore structure. The carbonyl structure in the FT-IR results indicated that the esterification reaction was successfully carried out. The results of XRD spectrum showed that the modification process occurs in the amorphous region. The OAS-PS/CS-Cur microcapsule has good encapsulation efficiency and sustained-release properties.

Abstract:Physicochemical properties of trimmed old leaves from tea trees were analyzed in comparison with normal and older large-leaf sun-dried tea (Camellia sinesis Var. assamica). Moreover， water extract was prepared from trimmed old tea leaves， which was then inoculated with Aspergillus tubingensis for theabrownin (TB) production via submerged fermentation. Results showed that there was little difference in nutritional components between normal and older large-leaf sun-dried tea. However， contents of water-soluble polysaccharides， amino acids， protein， total polyphenols， total flavonoids， catechins， theaflavins， thearubigins and TB of trimmed old tea leaves were significantly lower than those of normal and older large-leaf sun-dried tea (P<0.05). In contrast， its total water-soluble carbohydrates were significantly higher than that of normal and older large-leaf sun-dried tea. The optimum condition for TB production from water extract of trimmed old tea leaves by A. tubingensis was as follows: mass concentration of water extract 10 g/L， temperature 40 ℃， shaking speed 150 r/min. Under this condition， TB concentration reached 5.78 g/L， production rate 0.026 g/L·h， and yield 3.922 g/g. This study can provide basis for comprehensive utilization of trimmed old tea leaves and reducing production cost of TB.

Abstract:A method for γ-aminobutyric acid (GABA) production was studied using highland barley bran combined with adding sodium glutamate and pyridoxal 5'-phosphate (PLP). Based on the influences of different varieties on GABA bioconversion and the single test of factors including solution pH， initial whole flour concentration， reaction temperature and time， initial concentrations of sodium glutamate and PLP， the optimal reaction conditions of GABA production through the orthogonal experiment were developed. This research further showed that a strong influence of peeling level of barley bran on GABA enrichment. A safe and highly efficient preparing conditions without any buffer was determined as follows: bran peeling rate 4.23%-6.43%， barley bran concentration 140∶1 (g/L)， reaction time 12 h， reaction temperature 35 ℃， 8 mmol/L and 18 μmol/L supplemental level of sodium glutamate and PLP， respectively. The optimal reactions produced 19.57 mmol/L GABA from 8 mmol/L sodium glutamate， with a GABA conversion rate up to 97%.

Abstract:The preparation conditions including transaminase (TGase) activity， treatment time and casein/ hemp protein isolate (HPI) ratios were optimized through response surface methodology (RSM). The in vitro digestibility， allergenicity and microstructure of the optimal complex were determined. The optimal cross-linking conditions were as follows: TGase activity was 31.90 U/g， treatment time was 2.06 h， and casein/HPI ratio was 10.51∶1.49. In this case， casein-HPI complex showed enhanced resistance to digestive enzymes and lower allergenicity before digestion or mild hydrolysis. In addition， TGase cross-linking changed the microscopic morphology of the protein， confirming the interaction between casein and HPI.

Abstract:In order to optimize the enzymatic digestion process of soybean meal， soybean meal peptides of moderate molecular mass and easy to digest and absorb were obtained. In this study， the effects of trypsin， alkaline protease， neutral protease， papain and keratinase on the hydrolysis degree， peptide yield， molecular mass and bitterness value of soybean meal during the semi-solid enzymatic digestion process were compared. A single-factor experiment was carried out using trypsin， which has a better enzymatic effect， and three conditions (liquid to solid ratio， soybean meal quantity and temperature) were selected to optimize the preparation process. The results showed that the peptide was produced in high yield (18.87%) by trypsin digestion at 40 mg/g， 36 h， 1 mL/g liquid to solid ratio， 30 g soybean meal and 50 ℃.

Abstract:In order to develop egg soy sauce， Aspergillus oryzae HN3.042 was used for Koji-making， and the processing conditions were optimized by single factor and response surface methods. The volatile organic compounds (VOCs) in egg sauce were studied by GC-IMS. The results showed that the optimum conditions of raw material steaming were as follows: moisture content of the raw material was 50%， temperature of the raw material was 95 ℃， and time of raw material steaming was 52 min. Under these conditions， the neutral protease activity was 2 418.5 U/g， and the sensory score was 81.9. The optimum conditions for Koji-making were as follows: ambient humidity was 86%， time of Koji-making was 54 h， addition amount of wheat bran was 32%. Under these conditions， the neutral protease activity was 2 970.3 U/g， and the sensory score was 94.5. The results of GC-IMS analysis showed that there were 87 kinds of Volatile organic compounds in egg soy sauce， including esters， alcohols， ketones， aldehydes. The flavor components of egg soy sauce are different from that of soybean soy sauce. The relative main flavor components of egg soy sauce are 1-pentene-3-ol， 2-hexanol， 2-methyl-butanol， 2-pentanol， 2， 3-pentanedione， 3-pentanone， methyl 2-methyl butyrate， pentyl acetate， ethyl acrylate， methyl butyrate， oxolane， furfural， hexanal， trans-2-octenonal， butyric acid and other substances. The results showed that it is feasible to make soy sauce koji with eggs， which laid a foundation for the subsequent fermentation of egg soy sauce.

Abstract:Objective: This study aimed to produce a high-quality walnut direct drinking oil. Methods: The walnut direct drinking oils were based on the recommended fatty acids intake of FAO， MATLAB software was used to program five walnut direct-drinking oil formulas， and the best formulas was obtained by physicochemical parameters， micronutrient content， sensory evaluation and GC-IMS flavor analysis. Results: The walnut direct drinking oil was in line with national standards， and its fatty acid composition was reasonable. The main flavor substances were 2-pinene， 2-furfurylthiol， methyl hexanoate and 2-ethyl pyrazine. The walnut direct drinking oil prepared with 36% walnut oil， 52% flavoured rapeseed oil， 10% sesame oil and 2% DHA algal oil had the lowest peroxide value (3.99 mmol/kg) and viscosity (61.67 mPa·s)， higher OSI (4.72 h)， the highest content of tocopherol (758.39 mg/kg) and phytosterol (1 588.79 mg/kg)， and good sensory evaluation (16 points)， which was the best walnut direct drinking oil formula.

Abstract:In this work， Litopenaeus vannamei was used as a raw material to study the changes of muscle protein quality characteristics at different storage times under partial freezing condition (-3 ℃)， and the radial basis function neural prediction model was established based on related protein indexes. The results showed that compared with fresh shrimp samples， after 30 d of partial freezing storage， the surface hydrophobicity， carbonyl content， TCA soluble peptide， myofibril fiber fragmentation index， hydrophobic interaction force， and disulfide bond content significantly increased to (68.12 ± 0.19) μg， (2.02 ± 0.08) nmol/mg pro， (6.29 ± 0.14) μmol tyrosine/g muscle， 55.11 ± 2.79， (7.82 ± 0.17) mg/mL， (5.77 ± 0.06) mg/mL， respectively. Ca2+-ATPase， total sulfhydryl content， ionic bonding， hydrogen bonding content， and endogenous fluorescence intensity significantly decreased to (0.13 ± 0.13) U/mg pro， (68.45 ± 0.47) μmol/g pro， (3.12 ± 0.48) mg/mL， (1.67 ± 0.14) mg/mL， 579.71 ± 20.67， respectively. Shrimp muscle proteins were denatured， oxidized and degraded in varying degrees， and the tertiary structure of proteins changed. The results of sodium dodecyl sulphate-polyacrylamide gel electrophoresis showed that the storage time was prolonged， and the large molecular weight proteins were degraded. Meanwhile， electrophoresis results showed that the storage time was prolonged and the large molecular weight protein was degraded. The error between the predicted value of the radial basis function neural prediction model and the experimental value was within ±10%. The results showed that the model could predict the protein quality of L.vannamei during partial freezing storage.

Abstract:In order to clarify the effects of protein oxidation on the quality of longissimus dorsi muscles from Qinchuan beef during chilled storage at 4 ℃， the contents of carbonyl and sulfhydryl groups， pH value， meat color， shear force， purge loss， centrifugal loss and moisture content were measured at different storage periods (0， 2， 4， 6 and 8 d). The results showed that with the increase of time storage， the content of carbonyl gradually increased， and the content of thiol gradually decreased. Muscle pH and centrifugal loss decreased from 0 d to 4 d and increased after 4 d. Purge loss increased gradually with increasing time postmortem. The value of L increased from 0 d to 4 d and then decreased after 4 d， the value of b gradually increased from 0 d to 8 d， and the value of a decreased with increasing time postmortem. The shear force increased before 4 d and then decreased after 4 d. With prolonging of time storage， the bound water (P2b) and the immobilized (P21) water decreased， while the content of the free water (P22) increased significantly. The results of Pearson correlation analysis showed that the content of carbonyl groups were significant negatively correlated with muscle pH， the value of a and the shear force (P<0.01)， and significant positively correlated with the value of b， the purge loss and the centrifugal loss (P<0.01). The content of sulfhydryl groups were significant positively correlated with muscle pH， the value of a and the shear force， and negatively correlated with the value of L， the value of b， the purge loss and the centrifugal loss (P<0.01). The results of this study provide theoretical guidance for the quality control of chilled beef.

Abstract:To study the effects of salicylic acid on the storage quality and fruit softening of blueberry. 'powderblue' was as the experimental materials， the blueberry was treated with different concentrations of salicylic acid (1.0，2.0，3.0 mmol/L) before harvest. The storage quality and fruit softening changes of blueberry were studied under the condition of (0.5±0.5) ℃ cold storage. The results showed that pre-harvest salicylic acid treatment could reduce the decay rate of fruits， especially the decay rate of fruits treated with 2.0 mmol/L salicylic acid was 21.88% lower than that of the control group after 80 days of storage. Compared with other treatment groups， 2.0 mmol/L salicylic acid treatment group effectively maintained fruit firmness， soluble solids， titratable acid， total phenol， vitamin C and anthocyanin content at a high level， and could effectively delay the increase of pectin methylesterase activity (PME)， polygalacturonase activity (PG)， galactosidase activity (β-Gal) and cellulase activity (Cx)， thereby effectively inhibiting the hydrolysis of fruit protopectin and reducing the accumulation of water-soluble pectin. Conclusion: Preharvest treatment with 2.0 mmol/L salicylic acid can effectively reduce the occurrence of fruit softening by regulating the cell wall metabolism of blueberry fruit， and can better maintain the storage quality of fruit.

Abstract:The present research was undertaken in order to study the effects of ozone on ROS and disease resistance of apricot fruits. Apricot fruits of "Saimaiti" was fumigated with ozone at 200 mg/m3 and stored in cold storage at (1.0±0.5) ℃. Natural incidence， MDA， cell membrane permeability， O₂-· production rate， H2O₂， CAT， SOD， POD， APX of apricot fruit were determined every seven days during storage. The results show that 200 mg/m3 ozone treatment could significantly reduce the natural morbidity of apricot fruit. On day 49 of storage， compared with the control group， the natural incidence in ozone-treated apricot fruits were 17.0%， which were reduced by 61.94% (P<0.05). Ozone increased the activities of CAT， SOD， POD and APX， effectively reduced H2O₂ content and O₂-· production rate， balance the antioxidant system of apricot fruit， delay the increase of MDA and cell membrane permeability， and slow down the degree of membrane lipid peroxidation. At the end of storage， the activities of CAT， SOD， POD， APX of the ozone-treated group were 47.5， 4.14， 1.98 U and 12.0 U， respectively， which were 1.48， 1.14， 1.15 and 1.58 times as high as those in the control group. Compared with the control group， the H2O₂ and O₂-· production rate in ozone-treated apricot fruits were 22.04 μmol/g， and 264.44 nmol/min·g， which were reduced by 20.61% and 37.04% (P<0.05). It shows that 200 mg/m3 ozone could regulate the activity of enzymes related to active oxygen metabolism and enhance the disease resistance of postharst apricot fruits. It is expected to provide theoretical reference for ozone's widely used storage and preservation of fruits and vegetables.

Abstract:S. aureus has a high detection rate in fresh pork， which is one of the main foodborne pathogens that pollute fresh pork， and poses a great threat to food safety and human health. In this study， Congo red Agar method was used to determine the quality， 96-well microplate quantitative analysis combined with scanning electron microscope to detect the film-forming ability， PCR method was used to detect the film-forming genes and adhesion genes. Finally， the isolates were analyzed by multi-site sequence typing (MLST). The results showed that the qualitative test of Congo red Agar method showed that 84.93% (62/73) of the strains were biofilm positive， and the 96-well microplate quantitative test showed that 94.52% (69/73) of the strains were biofilm positive. Scanning electron microscope showed that the strains with different adhesion ability were enriched in gradient on the steel plate. PCR test found that all the strains contained multiple adhesion genes， which carried icaD， clfA， clfB， fnbA and fnbB at the same time. The strains of icaD， clfA， clfB， fnbA， fnbB， cna； icaA， icaD， clfA， clfB， fnbA， fnbB and cna had the largest number of multiple adhesion genes， which were 30.14% (22/73)， 20.55% (15/73) and 15.07% (11/73)， respectively. In MLST test， 73 strains were divided into 26 ST types， 20 in summer and 12 in winter. CC1 and CC5 were dominant clones in summer and CC15， CC1 and CC5 were dominant in winter. In the phylogenetic tree， the isolates were correlated with domestic food， iatrogenic and animal isolates， showing genetic diversity. The results can provide a scientific basis for the safety supervision of fresh pork， the transmission and the traceability investigation of S. aureus.

Abstract:Taking Chinese cabbage as raw material， pickled cabbage was produced by natural fermentation at 22 ℃ with 2.5% salt. Collected the brine at different time during the fermentation process to measure the pH value， detect the number of lactic acid bacteria and total bacteria， isolate and identify the dominant lactic acid bacteria strain， analyze the microbial diversity and the succession of bacterial community during pickled cabbage. The results showed that during the natural fermentation of kimchi， the pH value of kimchi decreased from 6.0 to 4.15， the total number of lactic acid bacteria increased from 4.65 lg (CFU/mL) to 7.86 lg (CFU/mL)， and the total number of bacteria decreased from 9.11 lg (CFU/mL) to 8.65 lg (CFU/mL). A total of 27 strains of lactic acid bacteria were isolated from different stages， including 10 strains of Leuconostoc， 7 strains of Weissiella， 4 strains of Lactococcus lactis， 4 strains of Lactobacillus Campylobacter and 2 strains of Lactococcus pentosus. During the 7-days fermentation of kimchi， the dominant species of lactic acid bacteria gradually changed from Wessella to Lactococcus lactis， and finally the mesenteric candida successively became the dominant lactic acid bacteria. The heteromorphic lactic acid fermentation bacteria occupied the dominant position in the whole kimchi fermentation stage， and the homologous lactic acid fermentation bacteria participated in the kimchi fermentation in the middle and later stage of fermentation.

Abstract:Pyrophosphate can seriously affect human health. Therefore， it is necessary to control the content of pyrophosphate in food. In the acid medium， copper ion (Cu2+) can effectively catalyze the redox reaction between hydrogen peroxide and ninhydrin， leading to produce a strong fluorescence. When a small amount of pyrophosphate was added into the hydrogen peroxide-ninhydrin system， the above-mentioned fluorescence was obviously reduced. Based on this observation， a fluorescence strategy for the quantitative analysis of pyrophosphate was developed. Several experiment parameters， such as hydrogen peroxide concentration， ninhydrin concentration， Cu2+ concentration， reaction time and reaction temperature were optimized to investigate the effect of these factors on the fluorescence intensity. The result showed that， the optimized experimental conditions was set as follows: 3.0×10-5 mol/L of hydrogen peroxide， 2.0×10-3 mol/L of ninhydrin 6.0×10-5 mol/L of copper ion， 40 min of reaction time and reaction temperature at 30 ℃. Under the conditions，the relative fluorescence intensity displayed a good linear relationship with the logarithm value of pyrophosphate concentration in the range of 3.0×10-7-8.0 ×10-6 mol/L. And the detection limit and the relative standard deviation were 3.2×10-8 mol/L and 4.9% (C=1.0×10-6 mol/L， n=11)， respectively. The content of pyrophosphate in the shelled shrimp and hairtail samples were quantified by the proposed method， and the average recoveries were between 93.00% and 97.80%. This result showed that the developed method can be applied in the accurate detection of pyrophosphate content in the practical food samples.

Abstract:In order to demonstrate the flavor characteristics of brown rice with various colors， the differences in volatile profiles of five-pigmented brown rice (black， red， purple， yellow， and green) originated from Yang County， Hanzhong were compared by gas chromatography-ion mobility spectroscopy (GC-IMS). Results showed that 62 volatile odorants were detected by GC-IMS from 75 peaks of five-pigmented brown rice samples， including 30 aldehydes (63.48%-70.39%)， 10 alcohols (8.47%-16.81%)， 10 ketones (10.13%-15.09%)， 6 esters (1.64%-6.15%)， 2 furans (2.39%-4.94%)， 2 acids (0.35%-1.34%)， and 2 ethers (0.35%-0.79%). Principal component analysis showed that the accumulated contribution ratio of the first two components was 72.2%， indicating that GC-IMS data can distinguish the volatile components of five-pigmented brown rice raw materials in Yang County. By establishing the odor fingerprint of pigmented brown rice in Yang County， the volatile profiles of brown rice with different colors are visualized， which contributes references for the brand and quality characteristics of pigmented rice in Yang County.

Abstract:In this study， the changes of muscle quality of pearl Gentian grouper were analyzed under different keep alive time of waterless preservation， and Near Infrared Spectroscopy (NIRS) analysis technology was used to establish SIMCA qualitative analysis model of keep alive time without water for pearl Gentian grouper during water-free preservation. The quantitative analysis model of muscle glycogen was established by Partial Least Squares (PLS). The results showed that the hardness and cohesiveness of pearl Gentian grouper decreased significantly with the extension of preservation time (P < 0.05)， and the pH decreased from 7.0 to 6.7. The centrifugal loss rate increased from 5.83% to 8.55%， and the cooking loss increased from 21.7% to 30.5%. The low-field NMR analysis results revealed that， after 12 hours of waterless preservation， the peak area of T22 in grouper decreased by 2.53%， while the peak area of T23 increased by 111.63%. This indicates a decrease in non-mobile water content and an increase in free water content， with limited transformation from flow to free water. Consequently， muscle water holding capacity was reduced compared to fresh grouper. The correct discrimination rate of SIMCA qualitative analysis model was 93.3%， and it had the ability to distinguish fish with different retention time. The square root error of validation set of muscle glycogen quantitative analysis model established after Mean Phoebe preprocessing was 0.24， and the correlation coefficient of validation set was 0.89. The relative deviation between predicted values and actual values was between 0.01 and 0.15， indicating that the model has high accuracy and good prediction ability. It can be used for rapid detection of glycogen content in fish samples of grouper after preservation.

Abstract:In this study， a TaqMan real-time PCR method was established for rapid detection of black truffle derived ingredients. Specific primers and probes were designed according to conserved sequence of ITS gene of Tuber indicum complex to test the target gene fragment in the samples， and species-specific detection， sensitivity detection and practical application detection were carried out. Results showed that this real-time PCR method had strong specificity， only showed specific amplification curves for black truffle genomic DNA， but there was no amplification curve for other edible fungi， animal and plant materials. The limit of detection was 1.0×10-3 ng/μL genomic DNA or 0.01% (mass fraction) per reaction. The feasibility of the method was further verified by detecting 120 commercial black truffles (fresh， frozen， dry and powder)， black truffle products (black truffle sauce and black truffle seasoning powder) and miscellaneous bacteria bags without black truffle components. The black truffle components were detected in 70 black truffles and 10 black truffle products. This method has the characteristics of strong specificity， high sensitivity， rapidity and high sufficiency， and is suitable for rapid identification of black truffles ingredients.

Abstract:Ethyl Carbamate (EC) is a genotoxic and highly carcinogenic metabolite produced during the fermentation and storage of fermented foods and alcoholic beverages. Therefore， the control of EC content in fermented foods is an essential topic in the field of food safety research. In this study， strains degrading ethyl carbamate in vinegar brewing mass and fermented grains of Baijiu were isolated using EC as the sole carbon source. Forty-eight ethyl carbamate degrading strains were obtained， which were identified as 14 different genera， including Candidaethanolis， Rhodium magnolia， Delftia sp.， Enterococcus durans， Bacillus sq. and Enterococcus faecium， etc. The isolated Lysinibacillus fusiformis and Candida ethanolica were embedded and applied to remove EC from Chinese liquor after embedding and fixation. Strikingly， the concentration of EC in liquor decreased significantly. The results showed that the EC concentration in Chinese liquor decreased from 230.37 μg/L to 78.12 μg/L (L. fusiformis) and 86.97 μg/L (C. ethanolica) in both treatment groups at 12 h， with EC degradation rates of 66.09% and 62.25%， respectively. The results of this study can provide a reference for the excavation of acid-tolerant， ethanol-tolerant， ethyl carbamate hydrolase producing strains.

Abstract:The application of natural astaxanthin in antioxidant， immunity enhancement， anti-cancer， photoprotection and other physiological functions is limited by problems such as poor water solubility and easy degradation. The researchers ameliorated these problems to a certain extent through a variety of stabilization techniques， while enriching the types of astaxanthin products. In this paper， the literature on the stabilization technology of improving the bioavailability of astaxanthin through molecular structure modification and delivery system was reviewed， and the application of nanoencapsulation technology in the targeted delivery of astaxanthin was introduced. On this basis， the research status and existing problems of astaxanthin stabilization technology are considered and summarized， providing theoretical support for the development of astaxanthin-related foods and drugs.

Abstract:The protein kinase B is significant serine/threonine protein kinase in eukaryotic cells. It is also a pivotal downstream signal molecule of phosphatidylinositol 3-kinase. Akt can play a crucial role in protein metabolism by regulating the activity of mammalian target of rapamycin， glycogen synthesis kinase 3 or forkhead box； glycogen synthesis or glycolysis can also be regulated by phosphorylation of FoxO and GSK-3. It can also regulate sterol regulatory element-binding transcription factor and mTOR signaling pathway to promote lipid synthesis. In addition， it can phosphorylate FoxO， precursor apoptotic proteins (such as bad， Bcl-2) or Caspase-9 to inhibit the apoptosis pathway and ultimately affects meat quality. In conclusion， Akt and its downstream signaling pathways may be an significant target to improve meat quality. In this article， the activation mechanism and cascade effect of Akt as well as its effect on meat quality were reviewed， with the aim of providing a foundation for improving the meat quality.

Abstract:For a better understanding of the current status and development trend of food nutrition discipline， a bibliometrics approach was used to analyze the papers published in SCI-E database over the last 10 years. The results showed that the overall research achievement of global food nutrition has an annual growth trend， especially in the last 5 years increased significantly. The United States ranked first in the number of papers in the world， and China ranked second. Budging from the average cited times， the influence and quality of Chinese papers still lagged far behind that of the United States. Among the top 15 research institutes， the United States and France had the largest number of seats， but China had only one and the phenomenon of low the average cited times. At present， the development of food nutrition shows a trend of interdisciplinary integration， and nutrition and dietetics are the most important direction in food nutrition. The research hotspots around the world mainly focus on the bioactivity and mechanism of food effective components， dietary patterns and disease prevention， intestinal microflora and microflora， food safety and preventive policy. Anaerobic digestion， ultra-processed food， cardiovascular disease， biomas， food toxicity and safety， conventional agriculture and livestock， alternative feed， bioactivity， nutrients， malnutrition， microencapsulation， food frequency questionnaire， biomarkers are frontiers of food nutrition research.