Abstract:Objective:Alkaline electrolyzed water (AEW) produced by drinking water electrolysis with three different negative REDOX potential values was used to study its physical and chemical properties, antioxidant and gastric acid relieving capacity.Methods:The pH value, oxidation-reduction potential (ORP), total dissolved solids (TDS) and mineral content of AEW were determined, and the free radical scavenging rate and anti-lipid peroxidation ability of AEW were studied by spectrophotometry. The acid capacity of different water samples in vitro was studied by artificial gastric model.Results:The negative ORP value of AEW is positively correlated with the pH value (P＜0.01). The scavenging rates of superoxide anion, hydroxyl radical, ABTS+ and anti-lipid peroxidation of alkaline electrolyzed water were significantly different from those of tap water (P＜0.05), and the antioxidant capacity of AEW was positively correlated with the negative ORP value (P＜0.01). The neutralization ability of AEW to artificial gastric acid in vitro was significantly different from that of tap water (P＜0.05), and tap water has a certain dilution effect on gastric acid.Conclusion:AEW with different negative ORP value produced by electrolysis of tap water has antioxidant activity, which gradually increases with the increase of negative ORP value, and has the ability to relieve gastric acid excess, with equivalent effect of 0.2% NaHCO3.

Abstract:Objective: This study aimed to investigate the effect of tea water extract on liver deodorization of giant salamander. Methods: The changes of volatile components in liver of giant salamander treated with tea water extract for 0, 5, 10, 15 and 20 min, were analyzed by gas chromatography-ion mobility chromatography (GC-IMS) combined with sensory odor value. Principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) were performed on volatile compounds. Results: Compared with the control group, the fishy smell value of the liver of the giant salamander was significantly decreased after the treatment with tea water extract for 5 min (P＜0.05), and basically stable after the treatment for 10 min. A total of 32 volatile organic compounds were identified in the liver samples of the giant salamander at different deodorization times, including 10 kinds of alcohols, 8 kinds of aldehydes, 5 kinds of esters, 5 kinds of ketones, 3 kinds of alkenes and 1 kind of ether. The relative contents of alcohols, olefin, ethers and esters in the liver of the giant salamander decreased, while the relative contents of ketones and aldehydes increased. PCA results showed that the accumulative contribution rate of the first two principal components was 82%, which could achieve good differentiation between groups, while the aggregation degree was low within the sample group showing large difference within the group. Orthogonal partial least squares-discriminant analysis (OPLS-DA) and variable importance in projection (VIP) were used to screen out 10 potential feature markers (VIP＞1), including 4 kinds of ketones, 2 kinds of alcohols, 2 kinds of aldehydes, 1 kind of alkene and 1 kind of ether. In the deodorization process, with the extension of deodorization time, the relative contents of oct-1-en-3-ol, 2-butanone dimmer, 3-methylbutan-1-ol-monomer and 2-butanone-monomer decreased. The relative contents of hexanal-monomer, 3-methylbutanal-monomer and acetone increased. Conclusion: Treatment with tea water extract for 5~10 min can significantly reduce the liver fishy smell of giant salamander. GC-IMS technology combined with multivariate statistical analysis can distinguish the liver volatile organic compounds of giant salamander during the deodorization process.

Abstract:Objective:The effects of reheating methods on the quality of frozen cooked river crab were studied to provide a basis for the selection of reheating methods for frozen cooked crab. Methods:The crabs reheated with microwave and steaming without and with thawing were studied using reheating time, texture, flavor nucleotide, free amino acids and volatile flavor compounds. Results:The times of crabs reheated with steaming without thawing, steaming after thawing, microwave without thawing, and microwave after thawing to the center temperature of 75 ℃ were 720, 552, 173, 106 s, respectively. Compared with unthawed crabs, the reheated crab meat had lower reheating loss, hardness and chewiness. Compared with steaming, the crabs reheated by microwave had higher hardness, chewiness and higher contents of nucleotides and free amino acids. Compared with the thawed crabs, the unthawed reheated crabs had more volatile flavor compounds. Compared with steaming, the crabs reheated by microwave had more volatile flavor compounds. Thawed crabs had more taste compounds while unthawing could formatted more flavor compounds. Microwave could maintain taste compounds and formatted more flavor compounds. Conclusion:Reheating methods had no significant influence on texture of crabs. The crabs reheated with microwave had better flavor quality. The quality of crabs reheated with microwave after thawing was better.

Abstract:Objective: This study aimed to investigate the formation mechanism of starch-lipid complex. Methods: Using different fatty acids with carbon chain length of C12~C18 to complex with debranched / non-debranched high amylose corn starch, by measuring the thermal properties, crystalline structure and ordered structure of the complexes with differential scanning calorimetry, X-ray diffraction, and Fourier transform infrared spectrometer, the effects of fatty acid chain length and debranched/non-debranched high amylose corn starch on the structure and properties of starch-fatty acid complexes were explored. Results: The compound degree of debranched starch and fatty acid decreased with the increase of carbon chain length, and the composite rate of lauric acid (15.00%) was found highest. The degree of composite of non-debranched starch and fatty acids increased first and then decreased with the increase of carbon chain length, and the composite rate of palmitic acid (13.73%) was the highest. The thermal properties, crystal structure and ordered structure of the complexes were related to the compound degree. After forming complexes with fatty acid, the crystal structure of high amylose corn starch changed from B-type to V-type. Conclusion: Fatty acid chain length and starch debranching had great influence on the structure and physicochemical properties of starch-lipid complex.

Abstract:Objective:Zhangjiakou naked oats in Hebei province (HZ) and Qiqihar naked oats in Heilongjiang province (HQ) were selected as the research objects. The metabolites and differential metabolites of naked oats of the same variety in different regions were explored.Methods:Metabolomics research methods were used as the basis. Methanol was used to extract polar metabolic components, with Bis(trimethylsilyl)trifluoroacetamide (BSTFA) selected for derivatization, and the metabolites were determined through GC-MS technology and the NIST database.Results:A total of 56 kinds of metabolites were detected, including various carbohydrates and a small amount of secondary metabolites, in which HZ accounted for 38 kinds and HQ accounted for 45 kinds.Conclusion:The oat metabolites and their contents in the two regions were basically the same, which were common compounds. However, the concentrations of common compounds such as linoleic acid, elaidic acid, and palmitic acid were different, and metabolites such as D-gluconic acid and galactopyranose were specific.

Abstract:Objective:To study quality difference of different maize varieties based on amino acid content.Methods:16 Xinyumaize series varieties were used to be tested materials, amino acid content of corn kernel were measuredand used to be evaluation index and applied to principal component analysis and clustering analysis.Results:The affected order of maize varieties on 16 amino acid content was Met＞His＞Tyr＞Pro＞Thr＞Leu＞Glu＞Ser＞Phe＞Val＞Asp＞Ala＞Ile＞Gly＞Arg. 2 principal components were extracted by principal component analysis, its accumulative variance contribution rate reach to 90.227%, Ala, Ser, Glu, Leu, Asp, Phe and Met can be used to comprehensive assessment index of 16 maize varieties. Based on amino acid content, 16 maize varieties were divided into three groups by clustering.Conclusion:Comprehensive quality of both varieties Xinyu54 and Xinyu65 were better, those of Xinyu87 and Xinyu13 were relatively poor.

Abstract:Objective:This study aimed to enrich the source of natural antioxidants and antibacterial agents and explore the development potential of the biological activity of Aceraceae. Methods:The nutrition components ofAcer tegmentosum Maxim (AT) bark and the total phenols content and total flavonoid content of ethanol extract (ATEE) and water extract (ATWE) were measured, and the contents of salidroside and tyrosol were determined by HPLC. DPPH radical, ABTS cationic radical, hydroxyl radical scavenging ability and ferric reducing power of extracts were determined. The antibacterial activity was evaluated by measuring the minimal inhibitory concentration (MIC) againstStreptococcus mutans,Staphylococcus aureus andEscherichia coli. Results:The content of water, crude fat, crude ash, crude protein, carbohydrate and total dietary fiber of AT was 7.12%, 4.67%, 5.83%, 3.96%, 78.42% and 66.08%, respectively. The order of the contents of the four major elements was Ca＞K＞Mg＞Na, and the order of the contents of the six trace elements was Mn＞Fe＞Zn＞Al＞Cu＞Cr. The contents of TPC, TFC, salidroside and tyrosol of ATEE were higher than ATWE, and the contents were 315.66, 79.26, 183.26 and 26.89 mg/g, respectively. ATEE's DPPH radical, ABTS cationic radical, hydroxyl radical scavenging ability and ferric reducing power were higher than that of ATWE with not much different from VC and generally higher than BHA. The MICs againstS. aureus andE. coli were 128 and 16 μg/mL, respectively, but had no antibacterial activity againstS. mutans.Conclusion:The extracts of AT have good antioxidant and antibacterial activities.

Abstract:Objective:This study aimed to solve the problem of quantitative detection of adulteration of extracted camellia seed oil into pressed camellia seed oil.Methods:HS-SPME-GC-MS was used to determine and analyze the key aroma components of refined camellia oil and three kinds of extracted camellia oil with essence.The relative contents of aroma components in 4 kinds of original camellia oil and 10 kinds of roasted camellia oil were compared with those in extracted camellia oil. Fisher discriminant analysis was carried out with the characteristic data of aroma components in extracted camellia oil, and LDA model was established.Results:The key volatile components in tea oil extracted by refining were (E)-2-decenal, octanal, (E)-2-nonenal and nonaldehyde. The special aroma components of the three flavoring extracts were 2-methoxy-3-methylpyrazine, methyl cyclopentenolone and 2-methylpyrazine.The accuracy of LDA model was 84.0% and 83.6%, respectively, and it could identify the adulterated tea oil with 10% or more in the original and roasted tea oil.Conclusion:The LDA model of original camellia oil could well identify the extracted camellia oil with tea oil essence, but could not work in the model of roasted camellia oil.

Abstract:Objective:This study aimed to provides technical support for the risk prevention and control of nickel contamination in market soy milk powder.Methods:With concentrated nitric acid as digestion solution, the ultra-wave digestion was utilized for preprocessing, and then the ICP-MS, with Rhodium as internal standard to eliminate matrix interference and in the KED mode, was used to determine the content of nickel in soybean milk powder. Moreover, the conditions for ultra-wave digestion and ICP-MS were also optimized.Results:The linear relationship of the standard curves was located within the mass concentration of 0~10 μg/L, with correlation coefficient of 0.999 9, and the detection limit was 0.002 mg/kg. The recovery percent ranged form 94.5% to 100.6% and the relative standard deviation (RSD)was 1.8%~2.3%. The proposed method was validated on the quality control sample of soy milk powder (ZKQC5210) and the determination result was in the certification scope.Conclusion:The proposed method was correct and reliable, so it was suitable for the determination of the nickel content in soybean milk powder.

Abstract:Objective:This study aimed to establish UPLC method for simultaneous determination of seven kinds of saponins in Panax japonicus and evaluate its quality combined with chemometrics analysis.Methods:ACQUITY UPLC BEH C18 column (2.1 mm×100 mm, 1.7 μm) was used, and the mobile phase was water (A)-acetonitrile (B) with gradient elution. The flow rate was 0.4 mL/min, at 30 ℃, and the injection volume was 1 μL detected 203 nm. Cluster analysis, principal component analysis (PCA) and quality fluctuation analysis in chemometrics were used to identify the content determination results, in order to analyze the similarities and differences between Panax japonicus in different regions.Results:Seven saponins (ginsenoside Rg1, ginsenoside Re, ginsenoside Rb1, chikusetsusaponin Ⅴ, chikusetsusaponin Ⅳ, chikusetsusaponin Ⅳa and pseudoginsenoside RT1) had good linear relationship within the approved range (R2≥0.999 4). The average recovery rate was 99.00%~104.37%. The contents of ginsenoside Rg1, Re, Rb1, chikusetsusaponin Ⅴ, Ⅳ, Ⅳa and pseudoginsenoside RT1 were 0.21~18.85, 0.59~2.82, 1.25~8.12, 59.14~97.16, 22.21~47.19, 15.97~32.66 and 0.07~34.09 mg/g, respectively. According to the results of cluster analysis and principal component analysis, nine batches of P. japonicus samples were divided into three categories: S6 was classified as I; S3, S7 and S8 were classified as II, and S1, S2, S4, S5; S9 were classified as III. The quality fluctuation analysis showed that the contents of ginsenoside Rg1 and pseudoginsenoside RT1 fluctuated greatly.Conclusion:Simultaneous determination of seven saponins in P. japonicus by UPLC combimed with chemometrics comprehensive evaluation could be used for quality evaluation of P. japonicus.

Abstract:Through the application of blockchain technology to the construction of the organic food traceability system, the use of blockchain technology features such as decentralization, tamper-proof modification, and security insufficient network integration and inconsistent technical standards, combined with the construction of the organic food traceability system, proposed a sound organic food traceability safety system, perfect organic food traceability credit system, optimization of blockchain and organic food internet of things integration, and the establishment of a unified standard countermeasures and suggestions for organic food traceability standards.

Abstract:Objective:Aiming at the present situation of low efficiency, low accuracy and high cost in the sorting and processing of fishery industry in China, the intelligent sorting equipment and system of seafood based on robot was developed.Methods:Using the combination of intelligent robot and traditional machinery to develop a new mechanical structure to classify seafood, an intelligent recognition technology based on machine vision was used to classify seafood (the improved novel Faster R-CNN algorithm was adopted for seafood), and an equipment system that could automatically sort seafood intelligently, efficiently was constructed.Results:The improved novel Faster R-CNN algorithm has high detection accuracy in seafood detection.Conclusion:The equipment system can replace the traditional manual operation mode and complete the intelligent sorting process of seafood.

Abstract:Objective:In order to better plan the motion trajectory of the food sorting robot, reduce its vibration amplitude, and enable the food sorting robot to complete the task with high precision.Methods:Based on the delta parallel robot, combined with NURBS curve interpolation algorithm and improved genetic algorithm, a path planning method of food sorting robot aiming at the optimal motion time was proposed. The NURBS curve was optimized by improved genetic algorithm. The feasibility of the optimization method was verified by the comparative analysis before and after optimization through simulation.Results:Compared with before optimization, the proposed optimization method can reduce the motion time of food sorting robot to a certain extent, from 3 230 ms before optimization to 3 070 ms after optimization. The robot curve in joint space was also smoother, which can give full play to the performance of parallel robot.Conclusion:The trajectory planning method can effectively improve the sorting stability and efficiency of food sorting robot.

Abstract:Objective:To solve the problems of unstable grasping operation and low sorting efficiency of sorting robot in food production line.Methods:Based on the architecture of high-speed parallel food sorting robot, a multi-objective motion optimization strategy based on improved particle swarm optimization algorithm was proposed for the dynamic target grasping control method of food sorting robot. By coordinating the grasping sequence and sorting trajectory, the shortest path model was established. Establish the mechanism stability optimization model with the end acceleration, and optimized the target by improving the particle swarm optimization algorithm.Results:Through experimental verification, when the conveying speed was 100 mm/s, the grasping success rate was increased from 96.8% to 100%, and the sorting rate was increased from 1.62 to 1.98 s-1.Conclusion:This control method can effectively improve the operation stability and sorting efficiency of the food sorting robot.

Abstract:This paper located and planned the construction of the smart kitchen from the global and systematic levels, and put forward the overall functional framework of the construction of the smart kitchen system. Relying on the development status of existing kitchen equipment and from the aspects of basic selection principle, intelligent grade division and intelligent selection principle, the overall scheme of selection and upgrading of kitchen equipment was given in order to give full play to the functions of kitchen and effectively solve the pain points of traditional kitchen. Finally, the hot issues in the future development of intelligent kitchen system were prospected.

Abstract:Objective:To solve the problems of low automation level and low security of coconut meat digging machine in China.Methods:The coconut meat extraction device was designed by using several mutually fitting curved blade, electric push rod, compression spring, crank and rocker mechanism, pressure sensor and other mechanisms, and the automatic control system was designed according to the process of coconut meat digger, the coconut meat digger run stably.Results:The experimental device of coconut meat extraction can operate safely and stably, when the rotating motor speed was 130 r/min and the lifting motor speed was 150 r/min, and the average effective weight of coconut meat extraction exceeded 95% of the total weight of coconut meat.Conclusion:The experiment device of coconut meat extraction works stably and runs safely, which can improve the automation degree of coconut processing industry and has the value of popularization.

Abstract:Objective:In order to realize the intelligent grasping of tobacco stem in tobacco grading process, prevent the manipulator in the intelligent tobacco grading system from damaging the leaf surface during grasping tobacco leaves, and reduce the manual operation in the production of intelligent tobacco grading equipment.Methods:An automatic tobacco stem identification and location model based on improved YOLOv3 convolution neural network was proposed for the identification and classification of single tobacco leaf and the storage of corresponding single tobacco leaf in tobacco grading system. The model changed the structure of the unit module and introduced the attention mechanism module based on the original YOLOv3 model, which optimized the model parameters and used swish activation function to realize the target location and recognition of all the information of tobacco leaf images, and then the tobacco stem target detection model was constructed.Results:The results showed that the loss of improved YOLOv3 model could converge faster, with its mAP increased from 90.46% to 97.48% and its accuracy increased from 95.33% to 97.35%; its regression rate increased from 84.65% to 95.65%, which laid the foundation for the automatic classification of tobacco leaves.Conclusion:Compared with YOLOv3, Faster-rcnn, YOLOv4, Efficientdet algorithm, the proposed algorithm is lighter and more effective. It can reduce the hardware configuration requirements of tobacco stem test platform, improve the economic benefits of tobacco classification system, and provide accurate location information for tobacco feeding and storehouse separation in tobacco classification system.

Abstract:This study summarized the content, characteristics and development experience of nutrinform battery labeling which launched in 2020 through the official website of Italian government, relevant reports and literatures. The labeling adopted the nutrient profile of specific nutrient system showing contents of energy, fat, saturated fatty acid, sugar, salt and their percentage of adults? reference intakes (RIs) indicated with the battery content. As a voluntary labeling, nutrinform battery labeling which matched the Mediterranean diet pattern, popular in Italy. However, it is counterintuitive to be criticized as "Higher electricity lower nutritional quality" when applying for EU FOP labeling. The practical experience of developing the manual for the use of FOP labeling, planning the application of FOP labeling to unpackaged foods, and carrying out the comparison with other FOP labeling are important enlightenments for FOP labeling in China.

Abstract:Objective:In order to solve the problems of high failure rate of cigarette package steering mechanism of YB25 soft box packaging machine and easy to cause cigarette package damage, etc.Methods:Through the analysis of the wear of the parts of the cigarette package steering mechanism, the design defects of the mechanism were found. The three-point symmetric eccentric planetary gear train with more stable performance is designed, and the special clutch was improved to ensure its overload protection.Results:After the improvement, the failure rate of steering mechanism was reduced, with the single maintenance time 54 minutes reducing, the equipment noise 46 dB reducing, and the related quality defect cigarette packs 275 packs reducing within half a year, and the lower potential quality hazards.Conclusion:The improved cigarette packet steering mechanism achieves high-efficiency operation, effectively solves the problem of high failure rate of YB25 soft box cigarette packet steering mechanism.

Abstract:Objective:To solve the problems of consuming time and destroying samples in the process of detecting the sealing degree of cigarette packaging.Methods:A nondestructive testing method for sealing degree of cigarette cartridge was proposed based on non-contact deformation measurement technology and dynamic pressure difference. The cigarette package was placed in a sealed negative pressure environment, and the relationship between the maximum out-of-plane displacement and the cigarette cartridge leakage diameter was studied by quantitative analysis of the leakage aperture of the cigarette cartridge during volume expansion.Results:When the diameter of the leakage hole was0.2~0.8 mm, the deviation between the diameter of the leakage hole and the maximum out-of-plane displacement of the cigarette pack, and the deviation between the diameter of the leakage hole and the maximum out-of-plane displacement of the cigarette pack showed a trend of gradually decreasing. The difference could be clearly distinguished according to the diameter of the leakage hole. At 0.4~0.8 mm, the diameter of the leakage hole can be quickly obtained according to the deformation after 3~7 s of detection, and the correlation coefficient between the maximum out-of-plane displacement and the diameter of the leakage hole is more than 0.9, showing a strong correlation. The accuracy of the method is88.1%.Conclusion:The new cigarette packaging seal degree of nondestructive testing method is verified to be effective for real-time measurement in the production of cigarette carton industrial packaging.

Abstract:Objective:To understand the effects of changing the arrangement and position on the freezing characteristics of potato mash and the energy consumption of refrigeration equipment.Methods:Gambit was used to complete the establishment of the three-dimensional numerical model for the air blast freezing of mashed potato. At the same time, fluent 6.3 was used for unsteady state simulation, and Pr.c-15 pronton high-efficiency fresh-keeping refrigerator was used for the freezing test of mashed potato. In the test, the mashed potato was arranged in a row and fork row, and on this basis, the position of mashed potato was changed (rotated 180° clockwise) to validate the numerical model.Results:The numerical model is consistent with the actual situation. The relative error of freezing time is only 2.7%. Compared with the sequential arrangement, the cross arrangement had obvious advantages, the freezing time was shortened by 8.5% at most, the energy consumption was reduced by 4.5%, and the temperature variation coefficient and the non-uniformity of freezing time were also obvious; When the potato mash was arranged in a fork row, change the position at t=60 min and t=120 min, respectively. Compared with the same position, the change of position can further shorten the freezing time and reduce the energy consumption of the equipment on the premise of ensuring the quality of frozen products. Compared with no optimization measures (arranged in a row and the position remains the same), the energy consumption of the equipment can be reduced by 11.8% by adopting the measures of fork row and secondary position change.Conclusion:Changing its arrangement and position in the process of blowing freezing of potato puree will affect the flow field distribution around the potato puree, strengthen the heat transfer effect in the freezing process, and then affect the freezing characteristics of potato puree, such as shortening the freezing time, reducing the temperature variation coefficient and the non-uniformity of freezing time, The energy consumption of refrigeration equipment can be effectively reduced without affecting the quality of frozen products. Therefore, the above measures can be considered for optimization in actual production.

Abstract:Objective:This study aimed to compare and analyze the physical and chemical properties, texture changes and lipid oxidation of sauced beef by irradiation sterilization and high-temperature kettle sterilization.Methods:The irradiation dose was 2, 4, 6, 8 kGy, and the sterilization was performed at 121 ℃for 20 minutes in high temperature kettle.Results:The results showed that irradiation with a dose of 6 or 8 kGy had the same sterilizing effect as high temperature kettle, and could prolong the shelf life of beef. With the increase of irradiation dose,L*(brightness value) of soy sauce beef showed a downward trend as a whole, and theL*value of the sample in the irradiation group was higher than that in the sauced beef without sterilization, with thea*value increasing first and then gradually decreased. When the irradiation dose was ＜ 6 kGy, theb*value of the sample increased gradually with the increase of the irradiation dose, but when the irradiation dose was ＞ 6 kGy, theb*value of the sample decreased again. Moreover, the b*value of soy sauce beef in irradiation group was significantly higher than that in control group (P＜0.05); The hardness and elasticity maintenance of the irradiation group was better than that of high temperature kettle sterilization. The peroxide value and acid value of irradiated beef increased significantly with the increase of irradiation dose (P＜0.05), and high temperature autoclair sterilization had no significant effect on peroxide value of beef sauce. The acid value of irradiation dose of 8 kGy group and high temperature kettle sterilization group were significantly higher than that of other groups (P＜0.05), and the irradiation increased the initial malondialdehyde value of samples.Conclusion:Compared with the control group, the shelf life of soy beef in the 6 kGy irradiation group was longer and the irradiation treatment was more easily accepted by consumers.

Abstract:Objective:The effects and correlations of different concentrations of 1-MCP combined with (10±1) ℃ storage on flavor and texture of fruit were discussed.Methods:Soft solute' Hujingmilu' peach was used as test material. The concentration of 1-MCP treatment was 3.24, 6.48 and 12.96 μL/L respectively, then were stored at (10±1) ℃. The fruits stored at (10±1) ℃ and (1±1) ℃ without any treatment were used as control. The ethylene release rate, respiration intensity, fruit texture, sugar and acid content, five flavors of fruits in different treatment groups were measured every 4 days during cold storage. The fruit of different treatment groups that have been stored for 28 days were taken out and placed at a temperature of (20±2) ℃ and a relative humidity of 65% ~ 70% for 3 days, and the shelf quality was determined.Results:Compared with CK1, different concentrations of 1-MCP treatment stored at (10 ± 1) ℃ can delay the occurrence of ethylene release peaks, inhibit the ethylene release rate and breathing strength of the fruit, but still significantly higher than CK2; The sugar and acid content of that was significantly higher than CK2. 1-MCP treatment with a concentration of 6.48 μL/L combined with (10±1) ℃ storage can keep high TSS, sugar and acid content of fruits, inhibit the loss of sweetness, sourness, umami, and have good comprehensive flavor; It can significantly reduce the ethylene release rate and respiration intensity of fruits, and keep the inherent texture of fruits well.Conclusion:1-MCP with the concentration of 6.48 μL/L combined with (10±1) ℃ can not only delay the softening of fruits, but also make the secondary substances of fruits metabolize normally, and keep the inherent flavor and texture of fruits well. It can prolong the safe storage period of 'Hujingmilu' peach fruit to 20 days, which can be used as one of the fresh-keeping techniques instead of single low temperature storage.

Abstract:Objective:This study aimed to investigate the drying characteristic of Chaenomeles sinensis by using vacuum pulsed drying technology and establish BP neural network model.Methods:The single factor experiment of drying temperature (50, 60, 70 ℃), constant atmosphere time (2, 4, 8 min) and vacuum time (5, 10, 15, 20 min) on drying time, rehydration ratio, VC and general flavone content as well as microstructure of Chaenomeles sinensis during vacuum pulsed drying technology were investigated.Results:All the drying temperature, constant atmosphere time and vacuum time had significant influence on drying time(P＜0.05). The moisture effective diffusion coefficient (Deff) ranged from 6.044 8×10-10 to 12.008 6×10-10 m2/s in different drying conditions and increased with drying temperature increasing. BP neural network mode consisted of input layer, hidden layer and output layer. The input layer included four neurons named drying time, drying temperature, constant atmosphere time and vacuum time. The hidden layer included seven neurons and the output layer included one neuron named moisture content. The maximum error between simulated and experimental values was 4.77%. Rehydration ratio decreased as drying temperature increased and increased first and then decreased with the extension of atmospheric pressure time and vacuum time. VC and general flavone content increased first and then decreased with the increasing of drying temperature, atmospheric pressure time and vacuum time. The microstructure indicated that when drying temperature was70 ℃, the material surface crusted due to a large amount of water loss. In this case, the water migration channel collapsed and blocked. When drying temperature was 50 ℃, the surface of the material appeared a cellular porous structure, which was conducive to water diffusion and migration.Conclusion:The optimal drying process was drying at temperature 60 ℃, with atmospheric pressure for 5 min and vacuum for 15 min. In this circumstance, the drying time, rehydration ratio, VC and general flavone content were 12.1 h,6.28±0.05, (71.26±0.74)×10-2 mg/g and (19.27±0.33) mg/g, respectively. BP neural network model can describe the vacuum pulsed drying process of Chaenomeles sinensis.

Abstract:Objective:The study aimed to research the characterization, rheological properties and antioxidant activities of polysaccharide from Azolla.Methods:The polysaccharide was obtained through hot water extraction. The molecular weight, monosaccharide composition, microstructure, rheological properties and antioxidant activities were analyzed by gel-permeation chromatography (GPC), FT-IR spectrometric, scanning electron microscopy (SEM) and so on.Results:The polysaccharide from Azolla containing two groups of molecular weight (2 338.00 and 1.60 kDa) was an acidic heteropolysaccharide, which was mainly composed of mannose, glucuronic acid, galactose, xylose and glucose. The sample had the typical absorption peaks of polysaccharide, which connection mode of heterocephalic carbon was β-configuration. The micro level presented the network structure, and the molecules mainly existed in the form of flexible chains. The polysaccharide solution was the pseudoplastic fluid with shear thinning and had weak gel properties. The IC50 values of polysaccharide from Azolla for DPPH radical, ABTS radical and hydroxyl radical were 0.32, 1.00 and 0.96 mg/mL respectively.Conclusion:Polysaccharide from Azolla had good rheological properties and potential antioxidant activities.

Abstract:Objective:This study aimed to develop new rice bran products.Methods:The ACE inhibition rate was used as an indicator, and the rice bran protein was optimized by single factor and response surface experiments. The optimal enzyme hydrolysate peptides were separated by ultrafiltration, activity evaluation and amino acid composition analysis were performed.Results:The optimal process conditions were as follows: pH 7.2, mass substrate concentration 8.2 g/100 mL, enzymolysis at 46 ℃ for 3 h, and enzyme addition 0.3 g/100 g rice bran protein. Under the control of these conditions, the ACE inhibition rate of the enzymatic hydrolysate was (73.15±0.64)%, and enzymatic hydrolysate was rich in hydrophobic amino acids (23.09 g/100 g). Activity analysis showed that the ACE inhibitory activity (81.68±1.08)% of ＜3 kDa active peptide component at the same concentration (1.0 mg/mL) was better than those of ＞3 kDa active peptide component (58.65±2.21)% and (72.64± 1.61)%.Conclusion:The rice bran proteolysate obtained under the optimal process conditions has significant ACE inhibitory activity, and the molecular weight of the active peptide component significantly affects its ACE inhibitory activity.

Abstract:Objective:The protective effect and mechanism of seabuckthorn polysaccharides on insulin-resistant HepG2 cells against oxidative stress was investigated.Methods:The seabuckthorn polysaccharide was extracted by water extraction and alcohol precipitation method, and the polysaccharide content was determined by the phenol sulfuric acid method. The CCK-8 method was used to determine the effects of different concentrations of sea-buckthorn polysaccharides on the viability of HepG2 cells. HepG2 cells were induced with a medium containing 5×10-8 mol/L insulin for 24 hours to establish a HepG2 cell insulin resistance model. A kit was used to determine glucose consumption and relative glycogen content, and to determine the content of superoxide dismutase (SOD) and malondialdehyde (MDA). Western Blot method was used to determine the expression of oxidative stress-related proteins.Results:The content of sea-buckthorn polysaccharide was 88.46%. When the concentration of sea-buckthorn polysaccharide reached 800 μg/mL, the cell viability decreased significantly (P＜0.05). The subsequent safe dose was 400 μg/mL. Glucose consumption and relative glycogen content after seabuckthorn polysaccharide treatment were significantly increased (P＜0.05), SOD level reached (79.31±2.16) U/mg, MDA level reached (2.15±0.12) nmol/mg. After seabuckthorn polysaccharide treatment, the expression level of Nrf2 and HO-1 was significantly increased (P＜0.05), and the expression level of Keap1 was significantly reduced (P＜0.05).Conclusion:Hippophae rhamnoides polysaccharide can improve the abnormal glucose metabolism and oxidative stress level of insulin resistance cell model, and can improve insulin resistance by regulating the Nrf2/Keap1/HO-1 pathway.

Abstract:Objective:To study the protective effects of exo-polysaccharide of Rhodotorula mucilaginosa on drug-induced liver injury in mice and analyze its potential molecular mechanism, so as to provide scientific basis for the application of exo-polysaccharide of Rhodotorula mucilaginosa in functional food and drugs.Methods:Based on the antioxidant activity of polysaccharides, the effects of exo-polysaccharide component RmEPS-11 from Rhodotorula mucilaginosa on liver toxicity induced by INH and RIF in mice were evaluated.Results:Compared with the mice treated with INH and RIF, the levels of ALT and AST in serum and the content of MDA in liver were significantly decreased, while the activity of SOD and the content of GSH in liver were significantly restored. In addition, the histopathological damage of liver and the number of apoptotic hepatocytes were also significantly improved. The mechanism study showed that the protective effect was mainly due to the regulation of CYP2E1 mRNA expression level, resulting in the reduction of harmful free radicals and ROS formation, accompanied by the significant induction of antioxidant capacity.Conclusion:The polysaccharide RmEPS-11 extracted from R. mucilaginosa CM-1 can protect mice from acute liver injury induced by INH and RIF.

Abstract:Objective:To study the preparation process of carboxymethylated pumpkin polysaccharide and evaluate its antioxidant and hypoglycemic activity in vitro.Methods:Monochloroacetic acid concentration, reaction temperature and reaction time were further optimized by single factor tests and response surface tests, and the antioxidant activity test and hypoglycemic test were also carried out.Results:The optimum preparation conditions of carboxymethylated pumpkin polysaccharide were as follows: the concentration of monochloroacetic acid of 1.9 mol/L, reaction temperature of 73 ℃, reaction time of 3 h. Under the preparation conditions, the substitution degree of carboxymethyl polysaccharide was 1.247. Studies on antioxidant activity have shown that, within a certain range of mass concentrations, there was a dose-dependent relationship between antioxidant ability and mass concentration of pumpkin polysaccharide (PP) and carboxymethylated pumpkin polysaccharide (CM-PP). Hypoglycemic test showed that carboxymethylation of pumpkin polysaccharides also increased the inhibitory activity of α-glucosidase compared with the pumpkin polysaccharides before modification.Conclusion:The optimized technology of carboxymethylated pumpkin polysaccharide is reasonable and feasible, and has strong antioxidant activity and hypoglycemic activity.

Abstract:Objective:To explore the difference in composition and antioxidant activity of crude extracts of fermented soya beans with different solvent extracts.Methods:70% ethanol was used the extraction solvent, the fermented soya beans powder was extracted by ultrasonic method. After the solvent was evaporated, the crude extract was obtained. The crude extract was dispersed in water and extracted with petroleum ether, dichloromethane, ethyl acetate, and n-butanol in turn to obtain different solvent extracts. The colorimetry was used to determine the content of total flavonoids and total polysaccharides in crude extracts and different solvent extracts, HPLC was used to determine the content of 6 kinds of soybean isoflavones including daidzein. Then their scavenging effects were studied on DPPH free radicals, ABTS free radicals and OH free radicals, and the correlation was analyzed between antioxidant capacity and total flavonoids, total polysaccharides, and 6 kinds of soybean isoflavones.Results:The ethyl acetate extract had the highest total flavonoid content, which was (92.912±1.130) mg/g extract; The n-butanol extract had the highest total polysaccharide content, which was (83.381±0.754) mg/g extract, and the total content of isoflavones in the n-butanol extract was higher than the crude extract and other extracts. The crude extract of fermented soya beans and various solvent extracts showed in vitro antioxidant activity, among which n-butanol extract had the strongest in vitro antioxidant activity. The content of total flavonoids was significantly correlated with the content of 5 soybean isoflavones and antioxidant activity (P＜0.05).Conclusion:The n-butanol extract had a strong scavenging effect on three kinds of free radicals and could be used as a natural antioxidant.

Abstract:bjective:This study aimed to explore the composition, antioxidant activity and stability of purple potato polysaccharides and improve the efficiency of separation purification.Methods:The free radical scavenging capacity, antioxidant capacity and chemical stability of the crude polysaccharides from purple sweet potato were compared and analyzed by fractional alcohol precipitation.Results:The contents of polysaccharide, protein, sulfate group and uronic acid in the three fractions were in the order of PPSP-80% ＞ PPSP-60% ＞ PPSP-40%. Among them, PPSP-80% fraction had the strongest scavenging ability on DPPH, ABTS and superoxide anion free radicals, while PPSP-60% fraction had the strongest scavenging ability on hydroxyl free radicals. Whereas, PPSP-40% fraction had the worst scavenging ability on free radicals. The order of antioxidant effect on rapeseed oil was PPSP-80%＞PPSP-60%＞PPSP-40%, and PPSP-40% fraction had the worst stability, PPSP-60% had the best stability under extreme alkaline conditions, and PPSP-80% had the best stability at 121 ℃.Conclusion:Fractional alcohol precipitation has certain separation effect on purple sweet potato crude polysaccharides, and different alcohol precipitation components have obvious differences in antioxidant effect and stability. Therefore, the high concentration alcohol precipitated component had better antioxidant effect and stability.

Abstract:Objective:The study aimed to analyze the influence of malolactic fermentation on the aroma and deacidification of Rosa roxburghii Tratt wine.Methods:The organic acid content and volatile compounds were qualitatively and quantitatively detected by ion chromatography, HS-SPME/GC-MS and sensory evaluation.Results:The results showed that the malic acid content decreased by 85.83% during malolactic fermentation, with the lactic acid content increasing by 87.75%, 114 kinds of volatile compounds were detected during malolactic fermentation, including 48 kinds of esters (12 011.60 μg/L), 26 alcohols (1 409.50 μg/L), 13 acids (2 490.60 μg/L) and 10 alkane (749.70 μg/L), which were increased by 10.81%, 15.49%, 58.23% and 22.90% respectively, compared to those before malolactic fermentation. The sensory analysis results indicated the malolactic fermentation could increase caramel and floral flavor, decrease plant odor and the acidity, and improve the overall scorement of R. roxburghii Tratt wine.Conclusion:Malolactic fermentation can enrich the aroma of R. roxburghii Tratt wine, reduce acidity and improve the balance of taste.

Abstract:Objective:In order to improve the identification efficiency of cut tobacco.Methods:F-score feature selection method and AdaBoost ensemble learning method were used to recognize cut tobacco components. The texture, color and shape features of cut tobacco were extracted as the input of the model. The feature dimension is reduced by F-score feature selection method, and the support vector machine (SVM) was used as the base classifier, then AdaBoost ensemble learning method was used to get the classification model of cut tobacco.Results:This method could effectively distinguish different components of cut tobacco, and the recognition accuracy of each kind of cut tobacco was more than 95%.Conclusion:AdaBoost ensemble learning method is faster and more convenient than traditional methods, and also safer and more effective.

Abstract:Objective:In order to improve the quality of Agaricus bisporus bread, the appropriate additives were studied.Methods:In this study, vital wheat gluten, sucrose fatty acid ester and cellulase were used as additives to improve A. bisporus-wheat bread quality, and the study was optimized by using Box-Behnken experimental design.Results:By adding 3.35% of vital wheat gluten, 0.15% of sucrose fatty acid ester and 0.16% of cellulase, the comprehensive score of A. bisporus-wheat bread under optimal conditions can be improved. In addition, scanning electron microscopy detection results showed that the optimal A. bisporus-wheat bread could form a uniform and continuous network structure in the gluten matrix.Conclusion:The addition of vital wheat gluten, sucrose fatty acid ester and cellulase had significant effect on the comprehensive score of A. bisporus-wheat bread. The hardness decreased, specific volume and sensory score of the bread increased after optimization.

Abstract:Objective:This study aimed to provide a theoretical support for enhancing the quality of Hunan flavor marinated beef and improve the marinated process.Methods:The laws of beef quality and flavor change during pulse marinated, vacuum marinated micro pressure marinated and traditional marinated were investigated.Results:The NaCl content and percentage loss from cooked increased gradually in each marinated process beef with increased marinated time. The chromatic difference L* value decreased gradually, and the chewiness, hardness, elasticity increased first and then decreased. The sensory evaluation found the highest score and the time required to reach the highest score of pulse marination, vacuum marination, micro pressure marination and traditional marination were 89.6, 85.2, 86.1, 83.6, and 2.7 h, 3.0 h, 3.0 h, 4.0 h, respectively, Pulse marination had the highest sensory evaluation and the shortest time was required to reach the highest score. At the highest sensory score, the loss ratio of cooked was 23.18% in pulse marinated beef, which was lower than that of micro pressure marinated and traditional marinated (P＜0.05), and the chewability, hardness and elasticity were 5.15 N, 11.21 N and 0.782 mm, respectively,and these was superior to those of the other three marinated beef (P＜0.05), Muscle fiber bundles of pulse marinated beef were the least disruption in muscle tissue and the greatest gap between muscle fibers. The relative content of characteristic aroma compounds included Hunan flavor such as lauraldehyde, ethyl laurate and eugenol was highest at 12.3% in pulse marinated beef.Conclusion:Pulse marination is most suitable for Hunan flavor marinated production and can effectively improve the yield and food quality.

Abstract:Objective:The powder of purple yam was used as raw materials to replace part of wheat flour and then was applied to the production of steamed bread. The effects of purple yam flour on the quality and antioxidant activity of steamed bread were studied.Methods:The effect of different amount of purple yam powder on the texture and quality of steamed bread were investigated by measuring the specific volume, diameter-to-height ratio, color difference, texture, aging degree, moisture content, nutrient content and sensory evaluation. Moreover, the antioxidant capacity of steamed bread with purple yam powder was studied by measuring DPPH radical scavenging capacity.Results:The specific volume, diameter-to-height ratio and fat of steamed bread decrease, the color difference and protein increase, and the moisture content increased first and then decreased with the increasing amount of purple yam powder. Meanwhile, the addition of purple yam powder could help to delay the aging degree of steamed bread. On the other hand, the ability of DPPH radical scavenging rate for steamed bread showed an upward trend with the increase amount of purple yam powder.Conclusion:The addition of purple yam powder could improve the quality and the antioxidant activity of steamed bread. The research results could provide a scientific reference for improving the comprehensive utilization of purple yam powder and developing new functional steamed bread.

Abstract:Objective:This study aimed to investigate the effects of extruded mung bean powder, mushroom powder and egg powder on the quality characteristics of noodles and develop a nutritious vermicelli enriched with dietary fiber, polysaccharide and protein.Methods:The texture characteristics and sensory evaluation of extruded mung bean powder, mushroom powder and egg powder vermicelli were determined. Combined with the results of single factor, the optimal formula of vermicelli was optimized by orthogonal test.Results:The optimized formula parameters of nutritional vermicelli were as follows: extruded mung bean powder 4.00%, mushroom powder 1.20%, egg powder 2.00%; Under the control of these conditions, the optimum cooking time of vermicelli was (12.49±0.24) min, the water absorption was (204.72±3.09)%, the cooked strip breaking rate was (2.22%±3.85)%, and the cooking loss rate was (1.12±0.03)%.Conclusion:The vermicelli obtained under the optimized formula is smooth and neat, light brown green, and soft and smooth in taste, and also has a special flavor of mung bean and mushroom, with effectively increasing the content of multiple nutrients in the noodles.