Abstract:Objective: A new type of static mixer to enhance the ozone gas-liquid phase mass transfer was established in this study. Methods: The effects of different ozone gas flow rates, liquid flow rates and liquid temperature on the concentration of ozone liquid phase and the generation of hydroxyl radicals were investigated, and were compared with the microporous aeration method and the circulating jet method. Results: With the increase of the gas-liquid flow rate, the ozone water saturation concentration and the hydroxyl radical concentration both increased; as the temperature increased, the ozone water saturation concentration decreased, but the hydroxyl radical concentration increased. With the gas flow rate at 2, the liquid flow rate at 12 L/min and the liquid temperature at 10 ℃, the saturated concentration of ozone water reached 12.67 mg/L, and the concentration of hydroxyl radicals in ozone water was 85.11 μmol/L. The output of hydroxyl radicals was higher than that of microporous exposure. The air method and the circulating jet method increased by 73.4% and 20.6%, respectively. Conclusion: The new static mixer has a significant strengthening effect on the ozone-water liquid phase mass transfer and the generation of hydroxyl radicals.

Abstract:Objective: To study the technological conditions of preparing rice bran dietary fibers by cellulase hydrolysis, and analyze the reasons for the difference in the functional properties of different rice bran dietary fibers. Methods: Single factor experiment was used to optimize the process conditions. The chemical composition, oil holding capacity and sodium cholate adsorption capacity of rice bran dietary fibers were measured. And the microstructures of rice bran dietary fibers were observed by scanning electron microscope. Results: When the dosage of cellulase was 100 U/g, the reaction time was 5 hours, and the ratio of material to liquid （m _{rice bran dietary fiber}∶V _water） was 1∶15 （g/mL）, there were no significant change in the yield of insoluble dietary fiber and soluble dietary fiber. After hydrolysis, the cellulose and hemicellulose content of rice bran dietary fiber decreased significantly （P＜0.05） from 26.23% and 28.71% to 18.29% and 25.24%, respectively. And the lignin content increased significantly （P＜0.05） from 20.22% to 31.46%. Scanning electron microscopy analysis indicated that the surface of the soluble dietary fiber was dense and smooth, without obvious pore structure, and the surface of the insoluble dietary fiber after hydrolysis showed more and deeper pore structure. The oil holding capacity of rice bran soluble dietary fiber, insoluble dietary fiber and dietary fiber without hydrolysis were 0.86, 5.21 and 4.15 g/g, respectively. And the adsorption rates of sodium cholate of rice bran soluble dietary fiber, insoluble dietary fiber and dietary fiber without hydrolysis were 15.17%, 24.04% and 20.84%, respectively. Conclusion: The differences in the functional properties of different rice bran dietary fibers are caused by the differences in their chemical compositions and fiber surface structures.

Abstract:Objective: The adsorption performance of the seed-shell biochar from Moringa oleifera prepared under different technological conditions on methylene blue was investigated in this study. Methods: The magnetic seed shelling biochar (Fe₃O₄-MOS) and modified seed shelling biochar (KOH-MOS) were prepared by ultrasonic-assisted K₂CO₃-Fe₃O₄ co-impregnation pyrolysis and KOH impregnation pyrolysis at 1 000 ℃, respectively. The physicochemical properties of the samples were characterized by XRD, SEM and FTIR. On this basis, the adsorption characteristics of the two kinds of biochar for methylene blue (MB) solution were determined by equilibrium adsorption method. Then the adsorption isotherm and kinetic model were used to fit the data to study the adsorption mechanism of biochar on MB. Results: It was found that under the experimental conditions, the adsorption efficiency of Fe₃O₄-MOS and KOH-MOS on MB was close to 100%, and the maximum adsorption capacity calculated by Langmuir model were 116.83 mg/g and 99.37 mg/g, respectively. Conclusion: The adsorption of MB by the two materials is a process of spontaneous endothermic entropy increase and chemical adsorption. Fe₃O₄-MOS showed good magnetic separation ability, while KOH-MOS showed good adsorption ability.

Abstract:Objective: To explore the best fixation method of purple bud green tea. Methods: Using two or three leaves and a bud of self-selected purple bud strain 9803 as raw materials, fresh leaves were treated by microwave, pan-frying, steam and hot air to prepare green tea, and the representative green tea samples were selected for sensory evaluation and quality analysis of taste and aroma. Results: Among the four methods of fixation, the comprehensive score of sensory evaluation of microwave green tea was the highest (89.65), and the main physical and chemical components of microwave green tea, water extract, tea polyphenols, anthocyanins, amino acids, and caffeine remained significantly higher than the other three green tea(P<0.05); the phenol ammonia ratio, ratio of ester catechin to total catechin were the lowest, and were 12.18 and 0.72, respectively. Conclusion: The quality of purple bud green tea prepared by microwave method was the best among the four methods.

Abstract:Objective: This study focuses on obtaining a Lactobacillus strain for degrading triglyceride. Methods: Lactocillus was isolated from human breast milk and the faeces of healthy infants in this study, and their triglyceride degradability was determined by single reagent （GPO-PAP） method. The strains with strong degradation ability of triglyceride were selected for morphological, physiological, biochemical and 16S rDNA identification, and their tolerance to acid, bile salt and gastrointestinal juice was determined. Results: A strain of Lactobacillus Paracasei was isolated and then named as HCS17-040 （CGMCC No 19747）, and its degradation rate of triglyceride was （42.80±1.79）%; the survival rates of the strain were 89.35% and 87.18% after 17 h culture in pH 3.0 and pH 2.0, respectively, and then reached 94.75% and 92.97% after 17 h culture in 3 g/L and 5 g/L bile salts, respectively, the survival rate was 93.93% and 99.06% in artificial intestinal fluid for 4 hours. Conclusion: Lactobacillus Paracasei HCS17-040 has a certain ability to remove triglycerides, and has a good ability to resist acid, bile salt and artificial gastric and intestinal fluid.

Abstract:Objective: The organic acid content of green plum was determined, and the correlation between them was analyzed to provide basic data for further processing of products in Dazhou, Sichuan. Methods: The content of organic acids in green plum with different maturity was determined by HPLC, and the correlation of oxalic acid, tartaric acid, malic acid, ascorbic acid, L-lactic acid, acetic acid, citric acid, succinic acid, oleanolic acid and ursolic acid was analyzed. Results: In the same area, citric acid and malic acid in the fully ripe green plum in Jingshi town were higher than those in the seven ripe green plum, and citric acid in seven ripe green plum in Baijie town and Dushi town was higher than that in ripe green plum, while the malic acid was opposite. Correlation analysis showed that citric acid changed significantly with ursolic acid, L-lactic acid, acetic acid and oleanolic acid, whereas no significant correlation was found with malic acid. Conclusion: Citric acid (19.546%) of green plum is the highest content of organic acids in different areas of Dazhou, Sichuan, followed by malic acid (4.013%), which is higher than that in the green plum from other areas.

Abstract:Objective: To explore the changes of metabolites and antioxidant activity of soybean based plant fermentation broth during fermentation. Methods: The experiment was conducted to prepare the compound fermentation liquid from kidney beans and soybean by fermentation of yeast, Lactobacillus and other probiotics, The pH value, total acid, reducing sugar, soluble solids, total phenol, flavone content and antioxidant activity in the fermentation process were analyzed. Results: The pH value of fermentation broth decreased with the extension of fermentation time and gradually stabilized at about 3.55, the total acid content increased from 0.13 mg/mL to 0.43 mg/mL, and the soluble solid content decreased from 10.01% to 5.73%. The content of reducing sugar decreased at first and then kept fluctuating balance. The total phenol content increased rapidly in the fermentation process, and then stabilized at about 430 mg/mL. The content of flavonoids also increased with the fermentation, and then stabilized at 155.30 μg/mL. The reducing power and ABTS free radical scavenging capacity of fermentation broth showed a continuous growth trend, and reached a stable state in the late stage of fermentation, reaching the maximum value （0.608 and 3.404 mmol/L） at 48 h of fermentation, respectively. Conclusion: There is a certain regularity in the change trend of conventional metabolic components in kidney bean and soybean compound fermentation broth, and the fermentation broth has a certain antioxidant capacity.

Abstract:Objective: Studied the smoke emission characteristics of central electric heating cigarette. Methods: The release amount and stability of total and puff-by-puff mainstream smoke were investigated by taking seven domestic cigarettes （Cigarettes A-G） and one foreign cigarette （Cigarette H） as the samples. The factors that may influence smoke release stability were discussed. Results: ① The transfer ratios of nicotine and glycerol in Cigarettes H were the lowest; ② The smoke release stability of Cigarettes H was the highest; ③ The release behavior of TPM, nicotine and glycerol on a puff-by-puff basis all showed increase-decrease trend with the increase of puff sequence, which was different from the traditional cigarettes under ISO regime; ④ The tobacco retreated phenomenon when cigarette was inserted into its heating device had negative effect on the smoke release stability. Conclusion: The smoke release stability could be improved by reducing the tobacco retreated phenomenon of central electric heating cigarette.

Abstract:Objective: A high-precision, low-cost quantitative and rapid detection method of nitrite in food based on photoelectric detection principle was proposed, and a portable nitrite detector equipped with microfluidic mixer chip was constructed. Methods: The microfluidic mixer chip was designed to realize the rapid mixing of test samples. The mixing efficiency of the chip was verified by peristaltic fluid simulation. The influence of UV curing parameters on the microfluidic mixer chip channel accuracy was analyzed, the microfluidic mixer chip was prepared. The photoelectric detection system of nitrite was designed and established. The relationship between nitrite content and induced voltage was analyzed, the detection sensitivity of the system was determined. Results: The detection limit of photoelectric detection system could reach 95.7 μg/L at a confidence factor of 3. The fitting error of the linear index of the system was 0.996 7, the average detection time was 3 min. Conclusion: The UV curing technology can realize the high-precision fabrication of microfluidic mixer chip. The detection accuracy and sensitivity of the self-developed photoelectric detection system can meet the requirements of nitrite detection in food.

Abstract:Objective: The study focused on investigating the electrochemiluminescence properties of graphene quantum dots. Methods: By doping heteroatoms into graphene quantum dots (GQDs), the surface chemical reactivities and optical characteristics of GQDs could be effectively improved. Nitrogen and sulfur co-doped graphene quantum dots (NS-GQDs) were prepared using a one-step solonthermic method. Based on its excellent luminescent properties, an “off-on” electrochemiluminescence (ECL) sensor was constructed for the simultaneous determination of Fe³⁺ and F^-. Results: Under the optimal conditions, the quenched ECL value of NS-GQDs was linearly related with the Fe³⁺ concentration in the range 0.1~460.0 μmol/L, and the detection limit was 0.028 μmol/L; Meanwhile, the restored ECL value was linearly related with the F- concentration in the range 1~5 600 μmol/L, and the detection limit was 0.62 μmol/L. Conclusion: The quenching and restoring of the ECL signal had good reversibility. The proposed method was successfully applied to the determination of Fe³⁺ and F^- in water samples, suggesting its potential and significance in food analysis in the future.

Abstract:Objective: A new method for the rapid detection of chloramphenicol in eggs was established, by preparing the aptamer magnetic bead complex, based on the mechanism of inhibiting the catalytic color reaction between the DNase and heme. Methods: The aptamer and DNase was combined through complementary base pairing, and it was combined with aptamer composite magnetic beads. Furthernore, by adding different concentrations of chloramphenicol solution, the DNase and chloramphenicol nucleic acid adaptation was disintegrated by dissociation of DNase catalytic chromogenic reaction combined with hemoglobin. Results: The linear range of chloramphenicol was 0.001~100.000 mg/kg, and the absorbance was linearly correlated with the concentration of chloramphenicol. The recoveries of the colorimetric method were 98.4%~101.1% at 5, 10, 25 mg/kg, and the relative standard deviations were all less than 10%. Conclusion: By introducing DNASE and magnetic nanoparticles, this method can effectively overcome the false positive results caused by non-specific adsorption of traditional rapid detection methods, and is more suitable for rapid detection of chloramphenicol residues in eggs.

Abstract:Objective: The uncertainty of HPLC method for determination of 6-benzyladenine in a soybean sproutswas evaluated by QuEChERS pretreatment method. Methods: A mathematical model was established by analysis of uncertainty sources. Then the individual components of uncertainty were evaluated and the combined uncertainties and expanded uncertainties were calculated. Results: The results showed that the uncertainty caused by serval factors, including the configuration of standard solutions and gradient standard solutions, the fitting of the standard curve, the pretreatment process, the recovery rate and repeatability, and the instrument itself. The content of 6-benzyladenine was 0.335 mg/kg in agricultural products （soybean sprouts）. The relative combined standard uncertainty of the method was about 0.026 mg/kg, k=2. Conclusion: The main sources of uncertainty were the fitting of the standard curve, the configuration of gradient standard solutions and the recovery rate. QuEChERS method can simplify the pretreatment steps and reduce the solvent consumption and the uncertainty of the test.

Abstract:Objective: Solve the problems of low and inaccurate evaluation accuracy of the existing food safety risk evaluation methods. Methods: Based on the construction of food safety risk index, a food risk assessment method combining hidden Markov model and cuckoo search algorithm was proposed. The cuckoo algorithm was used to search the global optimal solution as the initial value of the hidden Markov model, and the Baum Welch algorithm was used for local correction to make it quickly converge to the global optimal solution. The superiority of this method was verified by the experimental analysis of dairy product data. Results: Compared with that before the improvement, the improved evaluation method was more accurate and effective, which could more accurately predict food quality and safety under the time characteristics, and the detection accuracy was more than 97.5%. Conclusion: This method combines time characteristics to predict, has high detection accuracy, and can provide effective risk assessment results for enterprises.

Abstract:Objective: This research aims to analyze the working condition of the material in the flow channel of the improved coaxial variable speed optimization twin-screw extruder. Methods: Used ANSYS/CFX to simulate and analyze the flow channel value, obtained the movement of the material, and compared it with the traditional screw twin screw. The performance of the two types of screws was compared and analyzed through the macro pressure field, macro speed field, velocity streamline diagram, and velocity vector diagram. Results: After the study, it was found that the pressure building capacity and mixing performance of the coaxial variable speed optimized twin screw were significantly better than that of the traditional twin screw, and the material transportation time could be effectively extended through the decelerated conveying in the middle section. Conclusion: The new optimized twin-screw, while retaining the advantages of the traditional twin-screw, additionally improves the pressure building capacity and mixing performance.

Abstract:Objective: In view of the problems of low human-computer interaction, insufficient modeling aesthetics and lack of design characteristics in the production line of steamed bread machine, the fuzzy evaluation method combined with AHP and TRIZ is used for the innovative design. Methods: The key areas of positioning design were obtained by analytic hierarchy process. The TRIZ standard engineering parameters were used to analyze the contradiction and construct the contradiction matrix. The invention principle was used to find the optimal solution of the design scheme, and the matter field analysis method was introduced to solve the specific practical problems of the steamed bread machine production line. Results: The fuzzy evaluation method was used to score the three modeling design schemes of steamed bread machine, and the relatively optimal scheme was obtained. Conclusion: According to the analysis of application examples, the rationality of this method to evaluate the design scheme of steamed bread machine production line is verified.

Abstract:Objective: In view of the fact that material selection for large-scale processing of jujube-clamping-peanut cannot be guaranteed and the food hygiene of manual operation cannot reach the standard, a small integrated machine for jujube-clamping-peanut was designed. Methods: The research status of jujube kernel removal was analyzed, the design index of small jujube-clamping-peanut integrated machine was formulated, and based on the process flow of jujube kernel removal and jujube-clamping-peanut, the mechanical structure of the jujube-clamping-peanut integrated machine was designed. Results: The prototype experiment shows that the jujube automatic charging and positioning rate was 94%, The peanut automatic charging and positioning rate was 97%; the average rate of production yield was 91%. Conclusion: The machine has the characteristics of accurate feeding positioning, simple structure, portable and easy operation, high yield, stable operation and so on. The machine can meet the technological requirements of jujube positioning and jujube-clamping-peanut.

Abstract:Objective: To improve the accuracy and comprehensiveness of permanent magnet motor stator winding fault diagnosis. Methods: A fault diagnosis model of permanent magnet motor stator winding based on stack autoencoder （SAE） was proposed, and a neural network composed of SAE and Softmax classifier was used to train the network with fault sample data. The simulated annealing particle swarm optimization （SAPSO） algorithm was used to optimize the connection weight and bias of the network, and determined the optimal network structure. Results: The network had been used to realize the fault diagnosis of inter-turn short-circuit, inter-phase short-circuit, inter-phase insulation reduction, and poor contact of the terminals of the permanent magnet motor stator windings. Compared with wavelet analysis +Softmax, spectrum analysis +Softmax and SAE+Softmax, the diagnostic accuracy of this method was the highest, and the diagnostic rate was 99.40%. Conclusion: The optimized SAE+Softmax fault diagnosis model has good robustness and is less affected by motor speed and load changes, which can improve the accuracy of permanent magnet motor stator winding fault diagnosis.

Abstract:Objective: At present, mechanical screening method is widely used in cigarette capsules size separation, which has some problems, such as low size detection accuracy, unable to separate different color capsules, leakage capsules and so on. Aiming at the quality detection of cigarette capsules, a quality detection system of cigarette capsules is designed and constructed, which integrates the functions of feeding transmission, machine vision image processing and rejection of unqualified products. Methods: In the detection system, the improved inter class variance method was used to extract the single shot image, and the automatic detection of shot quality was realized by gray analysis, unlimited transformation and improved minimum circumscribed circle algorithm. After the automatic image inspection was completed, and it would be rejected by the designed rejecting mechanism for unqualified products. Results: Through repeated experiments and application analysis, the total false detection rate of diameter or shape or worn capsules of unqualified capsules was less than 3%. It was showed that the proposed method could accurately eliminate unqualified capsules, which verified the feasibility and reliability of the system. Conclusion: The design of online detection system for cigarette capsules based on machine vision can complete the automatic online detection of the quality of the capsules, improve the detection speed and accuracy, and have reference value for improving the competitiveness of the market of the explosive capsules.

Abstract:Objective: To solve the problem of easily oxidized and high content of trans fatty acid the vegetable oil instead of solid fat. Methods: Soybean oil and rapeseed oil gels were prepared using sitosterol/soybean phospholipid as gel agent to replace solid fat. The oxidation stability was studied by the changes of primary oxidation products and fatty acid composition. The structural stability was observed by X-ray diffraction, and the shelf life was predicted by OXITEST method. Results: The contents of primary and secondary oxidation products of soybean oil gel and rapeseed oil gel were lower than those of crude oil. The oxidation of polyunsaturated fatty acids occurred mainly in vegetable oils and their gels during storage, and the fatty acid content of the gels changed little. The X-ray diffraction results showed that both soybean oil gel and rapeseed oil gel had stable β and β’crystal structure. The results of OXITEST showed that the lipid gel could effectively prolong the oxidation induction period （IP） and further prolong the shelf life of the lipid. Conclusion: Lipid gel has good structural stability and oxidation stability, can effectively prolong the shelf life of vegetable oil, and can be an effective substitute for solid fat.

Abstract:Objective: To study the microwave freeze-drying kinetics and product quality of Cornus officinalis. Methods: The microwave freeze-drying technology was used to analyze the drying characteristics, quality changes of total flavonoids and total phenols of Cornus officinalis under different microwave power （100, 200, 300, 400, 500 W）, and the related kinetic model was established. Results: The drying process of Cornus officinalis could be divided into two stages: rising rate and decreasing rate, and there was no obvious constant rate stage. The increase of microwave power could improve the drying rate and shorten the drying time. Data fitting showed that page model could accurately predict the change of moisture content in the drying process of Cornus officinalis. In the whole drying process, the total flavonoids content showed two stages of rapid decline and gentle decline, the total phenol content showed a rapid decline trend, and the higher the microwave power, the faster the total flavonoids and total phenol content decreased. The microwave power had significant effects on the rehydration ratio and color （P＜0.05）. Conclusion: Microwave power can increase drying rate and shorten drying time, but too high microwave power is easy to degrade the quality of dry products.

Abstract:Objective: A color change indicator card for visual detection of fresh sea bass was studied. Methods: Using 1% Papaver rhoeas L. pigment as indicator and methyl cellulose gel as film-forming substrate, the label was made to study the color difference（ΔE） of the indicative label. The response of ΔE to pH was studied. Meanwhile, the content of TVB-N, TBARS, pH value, indicator label color and the linear relationship among these factors and ΔE under 4 ℃ sea bass preservation were determined. Results: The results showed that the indicator label had good discoloration effect in the range of pH 2.0~9.0. The TVB-N of sea bass and indicator ΔE were significant. and the color change was pink-purple-chartreuse-sepia. Chartreuse means superior, and yellowish brown means qualified. When the intelligent label reached sepia, the sea bass was inedible. The color of indicator label could be clearly distinguished by naked eye. Conclusion: The results showed that the pigment indicator label could be used as the indicator label of sea bass freshness.

Abstract:Objective: This study aimed to optimize and improve the CenterNet method for detecting fruit defects. Methods: the lightweight convolutional neural network of MobileNetV3 was used to replace the original backbone network of CenterNet accelerate the detection speed, improve the module of MobileNetV3, enhance the detection ability of the model for small and medium-sized defective blocks of fruit, and optimize the pre detection stage of CenterNet to increase its detection accuracy. Results: The recognition rate of significant defects such as apples with diameter > 4 mm was 99.7%, and the detection speed was 113 FPS, with the model volume of 1.31 MB. Conclusion: Compared with models CenterNet _ Resnet18 and CenterNet_Shuffler, model MO-CenterNet has better balance in training time, detection speed and accuracy.

Abstract:Objective: To investigate the effect of storage time on the quality of paper-making reconstituted tobacco, the change of internal chemical components, tensile strength and thermogravimetric properties of paper-making reconstituted tobacco were studied. Methods: Continuous flow analyzer, tensile strength tester and thermogravimetric analyzer were introduced to analyze three kinds of paper-making reconstituted tobacco with different storage time. Results: The contents of total alkaloids, total sugar, total nitrogen and moisture of JS-A and JS-B samples changed significantly with the increase of storage time. While the content of total alkaloids and total nitrogen of JS-C samples didnt change much. Besides, storage time had a significant effect on the longitudinal tensile strength of the three kinds of reconstituted tobacco leaves. Further, for all of the samples, the maximum values appeared at 180 days. The weight loss rate and normalized enthalpy of the three samples in the second stage changed significantly with the increase of storage time, and reached the maximum value at 360 days. Conclusion:The suitable storage time of three kinds of reconstituted tobacco leaves was between 180 and 360 days.

Abstract:Objective: To study the drying shrinkage mechanism of tobacco leaves during the redrying process. Methods: Based on the theory of porous media and elasticity, combined with Fouriers law and Fick's law, the numerical simulation of the thermal expansion, hygroscopic expansion and temperature coupling process in the tobacco leaf drying process was realized. Results: During the redrying process, the maximum stress occurred when the tobacco leaves were dried for about 3 minutes. The moisture stress during the drying process was much greater than the thermal stress; During the low-temperature slow-curing process, the internal moisture evaporation rate of the tobacco leaves was low, so that the shrinkage rate of the tobacco leaves was not high; The shrinkage rate in the drying stage during the redrying process of tobacco leaves was 10%, and the maximum error was 3%. Conclusion: The moisture content is the main influencing factor of the drying shrinkage and deformation of tobacco leaves.

Abstract:Objective: The extraction process of collagen peptides from the skin of swordfish （Xiphias gladius） was optimized in order to efficiently obtain collagen peptides with hyaluronidase inhibition activity by single factor and response surface method. Methods: The response surface method was used to optimize the preparation of collagen peptide with hyaluronidase inhibition activity. In this paper, the enzyme-soluble collagen was extracted from swordfish skin by pepsin, and then the salting-out method was carried out to purify the collagen initially. The specie of collagen was identified by polyacrylamide gel chromatography with 7.5% separation gel. After the basic test carried out by single-factor method according to the degree of hydrolysis and hyaluronidase inhibition rate, the hyaluronidase inhibition rate was selected as the response value for the optimization of hydrolysis conditions of collagen peptide derived from the skin of swordfish via Box-Behnken response surface experimental method. Results: The results showed that the pepsin-soluble collagen was identified as the type I collagen. The optimized hydrolysis conditions for the type I collagen peptide with hyaluronidase inhibition activity were: 6 h of hydrolysis time, 8∶2 of complex enzyme ratio, 32 ℃ of hydrolysis temperature and 6% of enzyme mixture addition. The hyaluronidase inhibition rate of the type I collagen peptide under these conditions was 42.35%. According to the statistical analysis, the response surface model fitted well and there was no significant difference between the predicted and actual values of hyaluronidase inhibition rate （P>0.05）. Conclusion: Therefore, this hydrolysis process could be applied to the production of type I collagen peptide with hyaluronidase inhibition activity derived from the skin of swordfish.

Abstract:Objective: To study the antibacterial activity and stability of Polygonum chinense Linn extracts against standard strains of Staphylococcus aureus in vitro. Methods: The antibacterial activity of Polygonum chinense Linn extracts on the Staphylococcus aureus were determined by oxford cup test and microdilution broth method. The OD_{600 nm} value of S. aureus was used as an index, and the influence of pH, temperature, ultraviolet radiation and metal ions on its stability was explored. Results: The results showed that Polygonum chinense Linn extracts had certain inhibitory activity on Staphylococcus aureus, and the minimum inhibitory concentration was 8 mg/mL. In addition, Polygonum chinense Linn extracts had good antibacterial stability in the presence of heat treatment, acidic and basic condition, ultraviolet irradiation, but it was sensitive to metal ions. The antibacterial effect of metal ions on the Polygonum chinense Linn extracts was different,0.1 mol/L Na⁺ and K⁺ could reduce its antibacterial effect, but under the treatment of 0.1 mol/L Ca²⁺, the antibacterial activity was lost. Conclusion: Polygonum chinense Linn extracts had stable inhibitory activity against S. aureus in vitro.

Abstract:Objective: This study focuses on exploring the effect of perilla leaf extract on hypoglycemic in type 1 diabetic mice. Methods: Streptozotocin （STZ） was used to induce the establishment of type 1 diabetes （T1DM） mouse model, and then the normal group, model group, perilla leaf extract high-dose group （400 mg/kg）, perilla leaf extract low-dose group （200 mg/kg）, positive group （150 mg/kg） were investigated. During the test, the food intake and water consumption of the mice were recorded, and the fasting blood glucose （FBG） of T1DM mice was measured every week, and the glucose tolerance level （OGTT） was measured on the 28th day of gavage. Blood is taken from the eyeball later, the heart, liver, spleen, lung, and kidney are taken after dissection to determine the organ coefficient. Determination of total cholesterol （TC）, triglycerides （TG）, glycosylated hemoglobin （GHb）, superoxide dismutase （SOD）, catalase （CAT）, malondialdehyde （MDA） related indicators. Results: The results showed that compared with the model group, the food intake and water intake of T1DM mice treated with perilla leaf extract decreased, food titers increased significantly （P＜0.05）, and the FBG of T1DM mice treated with perilla leaf extract decreased significantly （P＜0.05）, the levels of TC, TG, and MDA were also significantly reduced （P＜0.05）, SOD, CAT significantly increased （P＜0.05）. Conclusion: The perilla leaf extract can hypoglycemic in type 1 diabetic mice.

Abstract:Objective: In order to study the effect of biotransformation of aroma producing bacteria on volatile components of Siraitia grosvenorii extract. Methods: Raoultella planticola VP4-4 was used to biotransform the extract of Siraitia grosvenorii, and the volatile component of Siraitia grosvenorii before and after fermentation were analyzed by simultaneous distillation extraction and gas chromatography-mass spectrometry（GC-MS）. Results: The main aroma components or aroma precursors in the fermentation products of Siraitia grosvenorii were hexadecanoic acid, （z）-6-octad ecenoic acid, （z,z）-9,12-octadecadienoic acid，methyl-Butanoic acid, hexanoic acid, （Z）-9-Octadecenoic acid ethyl ester, hexadecanoic acid ethyl ester, benzeneacetaldehyde, 5-methyl-2-furancarboxaldehyde, benzaldehyde, nonanal, 2-furanmethanol, Ethenyl-2-methoxy-phenol, etc. In addition, vanillin with strong milk flavor was produced by biotransformation. The number of acids increased from 6 to 11, and the relative content increased to 60.07%. The relative contents of esters, carbonyls, alkanes, alcohols and phenols were reduced to 30.72%, 4.07%, 0.81%, 0.34% and 0.29%, respectively. And the compounds increased from 50 to 64 after fermentation. Conclusion: Biotransformation endows Siraitia grosvenorii fermented products with rich natural aroma such as flower aroma, fruit sweet aroma and milk aroma, reduces the types and relative content of macromolecular irritant components, and plays a role in increasing aroma and reducing impurities.

Abstract:Objiective: In order to improve the extraction efficiency of polysaccharide from Ampelopsis grossedentata. Methods: Ultrasound-assisted enzymatic extraction method was used in this study to optimize the extraction process of polysaccharide from Ampelopsis grossedentata. The effects of ultrasound temperature, ultrasound extraction time, enzymolysis pH, ultrasound power and the addition of complex enzyme on the extraction efficiency of polysaccharide from Ampelopsis grossedentata were investigated by single factor test. And the significant factors, including enzymolysis pH, ultrasonic power and he addition of complex enzyme were by Plackett-Burman test. The optimal extraction conditions were obtained through the steepest climbing test and Box-Behnken test. Results: The optimal extraction conditions were as follows: the value of pH 4.30, ultrasound power 104 W, the addition of complex enzyme 1.20%, ultrasonic time 40 min, ultrasonic temperature 50 ℃. Under these optimized conditions, the yield of polysaccharide from Ampelopsis grossedentata was （7.22±0.06）%. And compared with that of hot water extraction, ultrasound extraction and complex enzyme extraction method, the yield was increased by 106.83%, 86.35%, 54.46%, respectively. Conclusion: Ultrasound-assisted enzymatic extraction method can obviously im-prove the yield of polysaccharide from Ampelopsis grossedentata.

Abstract:Objective: This study aimed to improve the hard texture and rough taste caused by the addition of whole wheat in the baking food. Methods: The effects of instant tea powder, whole wheat flour, baking time and β-glucoside on the quality of whole wheat flour bread were investigated with texture characteristics and sensory evaluation as indicators. Results: The results showed that there was no significant effect on the texture properties and sensory score of wheat flour bread when the volume of addition of instant tea powder was within 3%, andit was negative when the volume reached 4%. Meanwhile, whole wheat flour, baking time and β-glucoside also had significant influence on whole wheat flour. Conclusion: The optimized process of whole wheat flour bread is as follows: β-glucoside 0.12%, instant tea powder 2%, whole wheat flour 25%, baking time 35 min. Under the control of these conditions, bread hardness and chewiness were lower, resilience was better, and sensory score was higher.

Abstract:Objective: The hyperlipidemia rat model was established to study the hypolipidemic effect of compound kelp meal substitute powder rich in dietary fiber and unsaturated fatty acids. Methods: Male SD rats were divided into blank control group, model control group and high, medium and low dose groups: 6.58, 3.29 and 1.65 g/kg (equivalent to 10, 5 and 2.5 times of the recommended dose of human body respectively). The blank control group was fed with basic diet, and the other groups were fed with high-fat diet, and the three dose groups were given the corresponding concentration of compound kelp powder suspension by gavage. After four weeks of continuous intragastric administration, the serum levels of total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were measured, and the atherosclerosis index (AI) was calculated. Results: The three doses of compound kelp powder could reduce serum TC (low dose group P＜0.05, medium and high dose group P＜0.01), TG (P＜0.05) and LDL-C level (low dose group P＜0.05, medium and high dose group P＜0.01), and increase HDL-C level (medium and high dose group P＜0.01) showing dose-dependent. Moreover, it could effectively inhibit the increase of atherosclerotic index in hyperlipidemic rats (P＜0.01). Conclusions: Compound kelp meal substitute powder had a good effect on reducing blood lipid and anti-atherosclerosis.

Abstract:Objective： To enhance the content of aroma substances in burley tobacco after baking. Methods: Established the model between the content of reducing sugar after baking and the temperatures of the three drying zones, and optimized the temperatures of the three drying zones by the total amount of aroma substances of burley tobacco after baking. Results: The R² of the model was 0.947, and the fitting effect was excellent. The effects of temperature in drying zone 2 and 3 on aroma enhancement of burley tobacco was greater than that in drying zone 1, and the best baking conditions were 110 ℃ （3 min） of zone 1, 145 ℃ （3 min） of zone 2 and 135 ℃ （3 min） in zone 3. Conclusion: Under the optimum baking temperature, the content of reducing sugar in burley tobacco was lower and the total amount of aroma substances was the highest, which has the better aroma enhancement effect of baking.

Abstract:Objective: To establish a rapid method for the determination of stem content in finished tobacco by near infrared spectroscopy. Methods: The finished tobacco mixed with different proportion of stem silk （5%, 8%, 11% and 14%） was used as the test object. The near infrared spectrum information of pure stem silk, pure leaf silk and tobacco mixed with different proportion of stem silk was collected, respectively. Orthogonal Partial Least Squares Discrimination Analysis （OPLS-DA） was used to identify the overall difference of the near infrared spectral information of the above three kinds of samples. Variable Importance for the Projection （VIP） feature spectrum and full spectrum were used to establish linear non-negative regression models for stem silk samples of different proportions, respectively, and the accuracy and stability of the prediction models were evaluated. Results: ① The OPLS-DA pattern recognition analysis showed that there was a great difference in the overall NIR information of the three kinds of samples. ② Based on the VIP value greater than 1, the spectral wave number range was 4 000~4 165, 4 582~4 609 and 4 612~5 264 cm^-1. Wavelength range with large variance: 4 000~6 100 and 6 900~7 500 cm^-1. ③ The accuracy and stability of the prediction model established by the variance spectrum screening wavelength variable were superior to VIP algorithm and superior to the full wavelength variable. Conclusion: The method of NIR combined with linear non-negative regression coefficient regression for the rapid determination of the content of stem in finished tobacco has good stability and accuracy.

Abstract:Objective: The evaluation methods of cigarette quality stability based on different indexes are compared, which provides a theoretical basis for the selection of evaluation indexes of cigarette product quality stability. Methods: Used the heart-cutting two-dimensional gas chromatography （HC-2D-GC） to analyze the key components in cigarette smoke components. The fingerprint of qualified products was established, and the stability of cigarette product produced in different places within three years was evaluated by Euclidean distance similarity. The results were compared with the method based on the conventional parameters of cigarette smoke. Results: The smoke stability evaluation method based on the conventional smoke gas indicators cannot fully reflect the sensory changes caused by the changes of puffs. The similarity analysis based on puff-by-puff smoke components can more intuitively show the sensory quality fluctuations of cigarettes during puff-by-puff smoking. Using 3σ as the upper limit of control, and σ as the reasonable fluctuation range, and then use the sensory evaluation to determine the products in between, which is suitable as the method of evaluation of cigarette quality stability. Conclusion: The similarity analysis based on puff-by-puff smoke components is more effective in reflecting the sensory quality fluctuations of cigarettes than based on the smoke conventional parameters.

Abstract:The rapid detection methods of traditional probiotics， the next-generation probiotics based on immunological detection technology and molecular biology detection technology was reviewed, and the rapid detection technology development was prospected.

Abstract:This paper summarized the extraction process of fish oil, the method of non-stick oil sites, the health functions of docosahexaenoic acid （DHA） and eicosapentaenoic acid （EPA）, and the development of the oil industry in the future.

Abstract:The biological activities of Panax japonicus, including the effects on nervous system, digestive system, cardiovascular and cerebrovascular system, immune system, endocrine system and other systems were summarized and the quality control of saponins, nucleosides, polysaccharides and amino acids in Panax japonicus was analyzed in this paper. And its future research was prospected.

Abstract:The active compounds in sea buckthorn such as flavonoids, polyphenols, polysaccharides, vitamins, unsaturated fatty acids were introduced in this review, and their physiological functions such as anti-inflammatory, anti-cancer, immune regulation, anti-aging and anti-oxidation were discussed. Moreover, the problems faced during the development of sea buckthorn products, and the relative solutions were also summarized. This can help the development of sea buckthorn as functional products such as juice, wine, sea buckthorn oil, Jiaosu and yogurt, and contribute to improving the utilization value of various active compounds in sea buckthorn.

Abstract:This study carried out a case study on food GDAs （Guideline Daily Amounts） labeling in British. It was found that GDA_S labeling which has been implemented for over 20 years, changed from BOP （Back of Package） labeling to FOP labeling. The labeling shows the amount of energy, sugar, fat, saturated fat, and salt per serving, as well as the percentage of the recommended daily intake by using the specific nutrient system measurement model. The labeling lacks of color coding and visual icon, and its implementation is not as effective as most FOP labels. Therefore, it is suggested to display the nutrition information on FOP labeling in terms of food portion size units to facilitate consumers' attention and understanding.

Abstract:Objective: The influencing factors of blockchain application in food supply chain and the behavior problems of all participants in food supply chain are worth exploring. Methods: Using the evolutionary game method, the tripartite game model of food enterprises, government and consumers was constructed, and the replication dynamic equation was established; The effects of different initial values, access cost, premium coefficient and information authenticity on the choice of tripartite strategy were analyzed. Results: The steady state of the system was related to the proportion of the initial strategy population. The block link in cost had a great impact on the strategic choice of food enterprises. Too high access cost would inhibit the enthusiasm of food enterprises in information chain, which was not conducive to the application and promotion of block chain technology in food traceability system. The premium caused by accessing the blockchain would affect consumers' purchase enthusiasm. The none tamper ability of blockchain technology can improve the authenticity of food traceability information, which is conducive to the evolution of the three parties towards the ideal state. Conclusion: In order to fundamentally solve the authenticity of food traceability information, food enterprises should reduce the price of traceable food premium on the premise of ensuring the authenticity of traceability information, and the government should improve consumers' purchase enthusiasm on the premise of controlling the premium of traceable food.