Abstract:The use and cognition of food mechanical lubricants in food processing enterprises in China were investigated. The standards and regulations related to food mechanical lubricants at home and abroad were summarized and compared. And the composition and possible hazards of food mechanical lubricants and common edible oil used for lubrication were preliminarily explored. The necessity and safety feasibility of correct and reasonable use of food grade lubricants in food processing were demonstrated, and suggestions for food enterprises to use food grade lubricants reasonably and legally were put forward.

Abstract:This review summarized the research progress on the preparation methods of nano-delivery systems, the types of proteins used to construct plant polyphenol nano-delivery carriers, and the modification of nano-delivery carriers by cross-linking agents domestically and internationally. The development of protein-based plant polyphenol nano-delivery carriers in the food field was also prospected.

Abstract:Objective:In this paper, the inhibition of protein degradation in autolysis of white shrimp (Penaeus vannamei) surimi by extracts from the coelomic fluid of sea cucumber (Stichopus japonicus), a by-product of sea cucumber processing, was studied.Methods:The protein degradation in autolysis of white shrimp was studied by SDS-PAGE assay. Furthermore, the effect of sea cucumber coelomic fluid and its extracts on white shrimp protein degradation was determined by SDS-PAGE and TCA-soluble oligopeptide assay.Results:The optimal conditions of white shrimp autolysis were incubation at pH 3.0, 50 ℃ for 2 h. The bond intensities of myosin heavy chain around (200 kDa) and actin around (44.3 kDa) decreased suggesting the protein degradation of white shrimp. The sea cucumber coelomic fluid showed inhibitory effect on protein degradation in autolysis of white shrimp. When the concentration of coelomic fluid extract of sea cucumber was in the range of 6.25%~25.00%, the protein degradation was significantly inhibited. The release of TCA-soluble oligopeptide was also significantly inhibited by coelomic fluid extract at 12.50%~25.00%.Conclusion:Sea cucumber coelomic fluid extracts possess inhibitory effect on protein degradation of white shrimp, indicating suppression of white shrimp surimi autolysis.

Abstract:Objective:In order to explore the dynamic changes of volatile flavor components and their precursors during low temperature cooking of beef.Methods:Beef with central temperature of 98 ℃ was used as control group. Nucleotides, free amino acids, free fatty acids, total sugars and volatile flavor components in beef with central temperature of 60, 65, 70, 75 and 80 ℃ were determined, and sensory evaluation was carried out.Results:The results showed that the content of fresh flavor nucleotides, equivalent fresh flavor concentration and taste activity in the low temperature group were significantly higher than those in the control group (P＜0.05), and the inosinic acid content was the highest when the central temperature of beef was 65 ℃. The total amount of free amino acids was as high as 739.01 mg/100 g, and the content of free fatty acids in beef with central temperature 65 ℃ was significantly higher than that in other temperature groups (P＜0.05). The total sugar content decreased with the increase of beef central temperature, and aldehydes appeared in large quantities when the beef central temperature was 65~75 ℃. By calculating the odor activity values of the main flavor components, it was found that hexanal, nonanal, heptanal, octanal, benzaldehyde, ethyl acetate, pinene and p-xylene were the key volatile flavor compounds (ROAV≥1). Sensory evaluation showed that the beef with a central temperature of 70 ℃ had the highest comprehensive score and rich flavor.Conclusion:The above indexes fully show that the edible and flavor quality of beef is better when the central temperature is 65~75 ℃.

Abstract:Objective:This study aimed to explore the relationship between the structure and antioxidant activity of purified red date polysaccharide ZJP-1 and sulfated red date polysaccharide S-ZJP-1.Methods:Using remnant jujube as raw material, jujube polysaccharide (ZJP-1) was purified by hot water extraction, and then separated by DEAE-52 ion exchange chromatography and Sephadex-200 dextran gel column chromatography. Thereafter, red jujube polysaccharide sulfated derivative (S-ZJP-1) was obtain through chlorosulfonic acid-pyridine sulfated modification.Results:Both ZJP-1 and S-ZJP-1 are composed of three monosaccharides: glucose, arabinose, and galactose, but the ratios are different. The two polysaccharides had characteristic absorption peaks of polysaccharides, and S-ZJP-1 had characteristic absorption peaks of sulfate groups, indicating that the sulfation modification was successful. No triple helical structure was found in ZJP-1 or S-ZJP-1, while a sheet-like structure was detected. The results of the activity test confirmed that the polysaccharides ZJP-1 and S-ZJP-1 had significant scavenging activity on DPPH free radicals with reducing ability. When the mass concentration of the two kinds of polysaccharide was 0.5 mg/mL, the DPPH free radical scavenging activities were 40.4% and 47.6%, and the reducing ability is 0.419 and 0.531, respectively.Conclusion:The sulfate- modification jujube polysaccharide has higher antioxidant activity and is a good natural antioxidant.

Abstract:Objective:This article is aimed to explore the influence of closed/open conditions on the flavor compounds of Maillard reaction.Methods:The species and amounts of flavor compounds produced from Tyrosine-based Maillard reactions under closed/open conditions in different solvents and reaction temperatures were determined by GC-MS.Results:The results showed that the species and contents of flavor products are quite different under closed and open conditions. The amounts of alcohol flavor compounds were higher in closed system, while the amount of esters and ketones were higher inopensystem.Conclusion:The amounts of active oxygen and intermediates produced during the reactions likely result in the difference between closed and opensystems from the proposed mechanisms.

Abstract:Objective:This study aimed to understand the astringency perception difference and formation mechanism of different varieties of Chrysanthemum tea during drinking, and provide new research ideas and theoretical basis for the astringency perception and sensory research of edible flowers.Methods:5 different varieties of Chrysanthemum were selected to determined the main astringent chemical constituents by UV-Vis spectrophotometry. The perceiving intensity of the astringency of five different varieties of Chrysanthemum was measured and evaluated by using the intelligent taste analysis system of electronic tongue and the traditional sensory evaluation method. The interaction between the main astringent chemical constituents in Chrysanthemum and saliva BCA method was analyzed by SDS-PAGE method, Coomassie bright blue method and fluorescence spectrophotometer method.Results:Among the five kinds of Chrysanthemum, emperor Chrysanthemum and Bozhou Chrysanthemum had the highest content of polyphenols and flavonoids, and the corresponding characteristic value of astringency was also the strongest. The content of polyphenols and flavonoids was positively correlated with the astringency intensity of the Chrysanthemum tea.Conclusion:As the main astringent substance, the difference of polyphenols and flavonoids in different varieties of Chrysanthemum tea significantly affects the astringent taste, and the astringent substance in Chrysanthemum tea combines with proteins in saliva and precipitates, which is one of the main reasons for astringent.

Abstract:Objective:To understand bacterial composition and obtain isolated fermentative strains found in kombucha.Methods:The bacterial composition and dominant strains were analyzed using 16S rDNA high-throughput sequencing technology and traditional microbial culture method.Results:High-throughput sequencing showed that the bacterial community is richer and more diverse than the fungi community. Komagataeibacter,Acetobacter and Lactobacillus were the dominant bacterial strains, while Dekkera and Zygosacchaormyces were the dominant fungal strains. At the same time, 7 strains of acetic acid bacteria, 3 strains of yeast and 1 strain of lactic acid bacteria were isolated by traditional plate culture method, including 1 strain of Komagataeibacter saccharivorans, 1 strain of Acetobacter malorum, 4 strains of Komagataeibacter xylinus, 1 strain of Acetobacter, 2 strains of Zygosaccharomyces bailii, 1 strain of Dekkera bruxelensis and 1 strain of Lactobacillus plantarum.Conclusion:The results from high throughput sequencing were consistent with those obtained from traditional culture method.

Abstract:Objective:This study aimed to reveal the composition differences and antioxidant activities of kernel and peel from raw and fried semen from Ziziphi spinosae.Methods:Using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical, hydroxyl radical (·OH), superoxide anion radical (O-2·), 2,2'-amino-di (3-ethyl-benzothiazoline-6-sulphonic acid) ammonium salt (ABTS) free radical scavenging ability and ferric reducing antioxidant power (FRAP) to determine the antioxidant activity of peel, kernel and jujube benevolence from different semen. Moreover, the components of peel, kernel and jujube benevolence were also studied by UV spectrophotometer.Results:The results showed that the peel, kernel, and jujube benevolence of all the semen had certain antioxidant effects, and the order of their antioxidant capacity was peel＞ jujube benevolence＞ kernel. The composition study showed that the contents of total flavonoids, total saponins and total phenolic acids in the semen peel were higher than those in jujube benevolence and kernel, and there was no significant difference in the content of total polysaccharides among samples. Therefore, the pharmacodynamic material basis of antioxidant activity in the peel was verified to be flavonoids, saponins and phenolic acids. However, there was no significant difference in antioxidant activity, total saponins, total flavonoids, total phenolic acids and total polysaccharides between the raw and fried semen.Conclusion:The peel, kernel and jujube benevolence of raw and fried Ziziphi spinosae semen all have antioxidant activity, and this provides a theoretical basis for the further development and market application of Z. spinosae semen.

Abstract:Objective:This study aimed to analyze the differences of volatile compounds among fresh Gastrodia elata of different varieties and origins.Methods:Volatile components of fresh G. elata from six origin and three varieties were analyzed by gas chromatography-ion mobility spectrometry (GC-IMS) technology, and quantified and qualitatively from different angles using VOCal and Reporter, Gallery Plot and Dynamic PCA inserts and "nearest neighbor" fingerprint analysis.Results:In this study, a total of 75 kinds of volatile compounds were detected. Among them, 45 kinds of compounds were identified, including 16 aldehydes, 9 esters, 6 alcohols, 5 ketones and 3 acids. Principal component analysis (PCA) was used to effectively distinguish different varieties of fresh G. elata. However, it was not sensitive enough to distinguish the G. elata from different origins.Conclusion:GC-IMS can be used to quickly analyze the differences of volatile compounds in different varieties of fresh G. elata.

Abstract:Objective:To establish a method for the preparation of acetamiprid matrix reference material in cowpeas.Methods:Planted fresh blank cowpea which meets the requirements of reference material development was selected as the research object to obtain dry powder after crushed, freeze-dried, added, mixed, twice freeze-dried, crushed, screened, mixed, packaged and Co60 irradiation sterilized. The dry powder sample was determined by Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) and calibrated for quantitative determination by matrix standard solution. After homogeneity and stability studies, coordinated value was determined by 9 laboratories and the uncertainty was evaluated.Results:The prepared sample of cowpea freeze-dried powder had good homogeneity and stability, for which it was convenient to storage transport and preserve in stable status during the testing time. The property value and expanded uncertainty of acetamiprid was (0.283 7±0.008 5) mg/kg (k=2), certified by 9 independent laboratories.Conclusion:The matrix reference material prepared by this method has good homogeneity, stability and accuracy in request of the national metrology technical specification, which can be used in the quality control in process of testing, calibration of analytical instruments and development and verification of testing method, etc.

Abstract:Objective:In order to realize the rapid detection of the brewing age of mature vinegar.Methods:Electronic tongue (ET) and electronic nose (EN) combined with Densely Connected Convolutional Networks-Extreme Learning Machine (DenseNet-ELM) model were used to quickly detect the brewing age of mature vinegar. Two DenseNet models with different structures, ET-DenseNet and EN-DenseNet, were designed to extract the feature information of the electronic tongue and electronic nose signals respectively. And then the feature level information fusion method was used to obtain the fusion feature vectors of the two artificial sensory devices. Then Extreme Learning Machine (ELM) was used to classify and recognize the fused feature vectors.Results:DenseNet can effectively extract the deep features of electronic tongue and electronic nose signals, and its feature extraction ability was better than Discrete Wavelet Transform (DWT) and Convolutional Neural Network (CNN); Compared with the use of electronic tongue or electronic nose alone, the information fusion method had better accuracy and robustness for the detection of mature vinegar of different years. The Accuracy, Precision, Recall and F1-score of the test set reach 99.1%, 0.98, 0.99 and 0.99, respectively.Conclusion:The dense convolution network can alleviate the problems of model degradation and weak generalization ability caused by the increase of depth of the deep learning model, and can effectively classify seven kinds of aged vinegar with different brewing years.

Abstract:Objective:A detection method was developed for benazolin residual in rape and rapeseed by High performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS).Methods:The rape and rapeseed were extracted with acetonitrile reagent, purified by Pesti Carb-NH2, separated by C18 column, carried out with methanol-ammonium acetate aqueous solution, detected by HPLC-MS/MS.Results:The liner relation was good in the ranger of 0.01~1.00 μg/mL, and the coefficient of determination was 0.999, the limit of detection(LOD) was 0.008 mg/kg, with the limit of quantification (LOQ) of 0.027 mg/kg. At the spiking levels of 0.03, 0.06, 0.15 mg/kg, the recovery rate of the method was 73.3%~91.3%, and RSD was 4.4%~8.1%.Conclusion:The presedent treatment method is easily-conducing, efficient, and highly sensitive and selective, and it can be used to determine benazolin in rape and rapeseed.

Abstract:Objective:In order to develop a method, an easy handling of samples and accurate and rapid detection of erythrosine by ultrahigh performance liquid chromatography (UPLC) was established.Methods:The analysis was as follows: chromatographic column of ACQUITY UPLC BEH C18(100 mm×2.1 mm,1.7 μm), diode array detector with detection wavelength at 530 nm, column temperature at 40 ℃, mobile phase with acetonitrile and0.02 mol/Lammonium acetate solution (acetic acid to adjust pH 6.25), gradient elution including acetonitrile 0 min-5%, 2 min-25%, 3 min-45%,6 min-70%, 6.5 min-5% and 8 min-5%, flow rate at0.3 mL/min, and with injection volume of 5 μL. The pH of samples was adjusted to 7.00 by ammonia. Then 5% acetonitrile aqueous solution was used to extract with ultrasonic for 30 min. After filtration by0.20 μmfilter membrane, it was directly measured by UPLC.Results:The correlation coefficient of erythrosine standard curve was greater than 0.999. The spiked recoveries ranged from 92% to 109%. The relative standard deviation (RSD) was lower than 3.2%. The limit of detection (LOD) was0.01 mg/Land the limit of quantification (LOQ) was 0.03 mg/L.Conclusion:The method was suitable for accurate and rapid determination of erythrosine in a large number of beverages.

Abstract:Objective:The element content and physical and chemical quality were analyzed from the nutritional quality of Selenium (Se)-enriched rice in Ningxia.Methods:25 rice samples from different brands in Ningxia were selected as the research object, and 26 mineral elements in which were determined by inductively coupled plasma mass spectrometry (ICP-MS), and multivariate statistical analysis of these elements was conducted.Results:Through the analysis of the difference of element content between Se-enriched rice and ordinary rice, the quality of Se-enriched rice was distinguished. Moreover, it was found that Se-enriched rice was rich in four kinds of elements such as Ca, Sn, K and Mg. Other quality indexes of Se-enriched rice were analyzed. It was found that Se-enriched rice was imperfect, with low grain, low yellow grain, low chalkiness, high head rice rate, high amylose, high taste value, high freshness score, suitable hardness, elasticity and adhesion, good palatability, and high appearance quality and edible quality.Conclusion:Se-enriched rice can be distinguished by the difference of element content, and the Se-enriched rice in Ningxia has high nutritional value and eating quality.

Abstract:Firstly the research background and the current status of online food safety research were introduced, and then the current status and problems of online food supervision were analyzed in this review. Finally, some supervision strategies were proposed in four ways, i.e., the construction of a smart collaborative supervision platform, the reform of supervision organization and power reshaping, the breaking information asymmetry and the strengthening of consumer rights protection.

Abstract:Objective:To explore the influence of different screw configurations of intermeshing co-rotating twin -screw extruder on the flow field and improve the material properties of PLA.Methods:The geometric model of double threaded element was established by using Solidworks software, and the numerical simulation was carried out in Polyflow. The post-processing analysis of the simulation results was carried out with the help of Fieldview software. The shear rate field, pressure field, velocity field, viscosity field and the residence time distribution RTD were compared to obtain the influence of screw groove depth on the flow field.Results:When the center distance was the same, the depth of the screw groove was changed by changing the ratio of the outer diameter to the inner diameter of the threaded element, physical fields and mixing performance had great differences in the flow field of intermeshing co-rotating twin-screw extruder under the same process conditions. Compared with configuration 2, configuration 1 had stronger shear effect, but configuration 2 had better pressure building ability. In the extrusion process, configuration 2 had good axial mixing ability but poor self-cleaning ability, while configuration 1 had poor axial mixing ability and good self-cleaning ability.Conclusion:The change in screw groove depth has certain effects and rules on the mixing performance of the flow field, which can effectively guide the design of threaded element for twin-screw extruder.

Abstract:Objective:Solve the problems of low working efficiency and low filling accuracy of beer filling machine.Methods:The structure and working principle of beer filling machine were analyzed, and the control mode based on the weight deviation of secondary supplementary filling was determined; On the basis of PLC controller, using the characteristics of strong anti-interference ability of fuzzy algorithm and good self-adaptability of neural network algorithm, a PID control strategy based on fuzzy neural network was proposed, and simulation analysis and filling test were carried out.Results:Within the set target range, the maximum deviation of filling weight was only 1.7 g, and the filling qualification rate was 100%. Compared with the traditional PID control, the response speed of the algorithm was improved by 55% and the filling accuracy was improved by 50%.Conclusion:The test method can effectively improve the filling accuracy and filling efficiency, and can meet the requirements of stable, fast and reliable operation of automatic production line.

Abstract:Objective:To study the physical and geometric factors that affect the extrusion effect between particles in the spiral extrusion dewatering device for kitchen waste, and to provide reference for selecting the parameters of the spiral extrusion and dewatering device.Methods:Based on the discrete element method, the state of the extruded particles was analyzed, and the extrusion situation of the material particles in the device was simulated by changing the filling coefficient, spiral speed and inclination angle.Results:When there was some inclination angle in the screw extrusion dehydration device with variable pitch, the filling coefficient increased and the rotation speed up, and the extrusion pressure between the material particles increased accordingly.Conclusion:When the filling rate was 60%, the screw speed was 60 r/min, and the angle was 15°, the extrusion performance of the screw extrusion device could be significantly improved.

Abstract:Objective:In view of the existing rubber seed shelling machine, which have poor shelling and whole-kernel rate, is not enough to meet the needs of rubber seed shelling under different condition, a combined rubber seed shelling machine was designed. Through the combination of cutting and shearing of rubber seeds between the groove plate and the rotary blade, as well as extrusion and collision of the rotary blade roller, the shell is removed.Methods:The discrete element software EDEM was used to establish the discrete element model of rubber seed and shelling machine, and to simulate the separation process. Response surface method (RSM) was used to analyze the influence of shear extrusion clearance, blade roller speed and blade-roller installation phase on rubber seed shelling and whole-kernel rate. The best working parameters were optimized and verified by experiment.Results:The designed combined rubber seed sheller can achieve better shell kernel separation and obtain a higher kernel rate. When the shear extrusion clearance was 12.6 mm, the blade-roller speed was 300 r/min, and the blade-roller installation phase was 40.5°, the shelling rate and whole-kernel rate of rubber seed were 94.09% and 96.47%. According to the best parameter combination, the shelling rate and whole-kernel rate of rubber seed were 89.67% and 91.33%.Conclusion:In the design process of rubber seed shelling, the discrete element method can be effectively used to analyze the influence of different structural parameters on the performance indicators.

Abstract:Objective:This study focus on solving the problems that the current beverage bottle cap detection system has simple functions, large volume and low color recognition rate.Methods:A design scheme of small beverage bottle cap color recognition system based on ARM processor was proposed. By using the LineSim tool of the simulation software HyperLynx, a four-layer PCB board was designed and impedance matching simulation analysis was obtained after setting transmission line parameters. Through using the compilation software Jupyter Notebook to achieve threshold setting, target contour detection, target frame out and other functions.Results:Under bright and low light conditions, the bottle cap targets of red, green and blue were tested, and the recognition rate of the design scheme for the three colors could reached more than 92.7%.Conclusion:Compared with the Fourier descriptor, the scheme has higher recognition accuracy and precision, and the system also has the function of face recognition, which is suitable for various intelligent application scenarios.

Abstract:According to the perceptual engineering research paradigm, rock tea packaging design research framework of perceptual engineering is used as a guide to determine the typical samples and core perceptual vocabulary of rock tea packaging through various methods such as literature search, expert evaluation, KJ method, questionnaire survey, etc. The semantic difference method is used to quantify user perceptions and conduct principal component analysis to arrive at rock tea packaging presenting four core perceptual attributes: bright, environmentally friendly, exquisite and the mapping relationship between the core perceptual vocabulary and design elements was obtained through class category analysis to obtain a rock tea packaging design that fits the perceptual cognition of young consumers.

Abstract:Objective:This study aimed to provide strategy for controlling the fungal diseases of postharvest blueberry in Sichuan province.Methods:The pathogenic bacteria from 14 planting bases in Sichuan Province were isolate, identified, pathogenicity determination. Moreover, the effects of temperature and light on mycelia growth of the dominant and subdominant strains of blueberry after harvest were studied, and the effective natural antibacterial components against them were screened.Results:The blueberry postharvest rot diseases were caused by the following nine kinds of fungi:Aspergillus niger,Aspergillus tubingensis,Neofusicoccum parvum,Neopestalotiopsissp.,Fusarium graminearum,Alternaria alternata,Mucor fragilis,Penicilliumsp.,Cladosporium xylophilum.Aspergillus niger was the dominant species with the highest isolation frequency and the most pathogenic, andNeopestalotiopsissp.,Alternaria alternata,Penicilliumsp.,Cladosporium xylophilum were the subdominant species with isolation frequencies greater than 10%. The optimum growth temperature ranged from 20 ℃to 35 ℃of dominant and subdominant strains of blueberry postharvest. The effects of light on the mycelia growth ofA. niger，Neopestalotiopsissp., A. alternata,and C. xylophilum were significant，but that was insignificant on the growth ofPenicilliumsp.strains. Thymol showed good broad-spectrum antibacterial activity, the EC50 values of dominant and subdominant strains of blueberry postharvest was 30~50 mg/L, while the thymol applied directly to blueberry postharvest fungal control in aqueous solution should not be higher than 50 mg/L.Conclusion:Thymol is more effective on postharvest diseases of blueberry in Sichuan province.

Abstract:Objective:Using Xinjiang melon as raw material, explore melon slices in weak microwave-assisted hot air drying in the process of drying characteristics.Methods:UsingR2,χ2 and RMSE as evaluation indexes, compare melon slices of wet basis moisture content under different conditions, the drying rate, moisture content than the distinction, and melon dry dynamics model was set up, and the drying characteristic curve of melon slices was gotten at different slice thickness, the cycle time of microwave, the hot air cycle time.Results:The thinner the slice, the longer the circulation drying time of microwave and dry hot air, the faster the moisture content of the dry base decreased. The faster the drying rate, and the more the moisture ratio changes. The drying process of melon slice can be divided into two stages, accelerated drying and reduced drying, and accelerated drying was the main drying stage. Different slice thickness, microwave circulation time and dry-hot air circulation time, the Thompson equation can better reflect the drying characteristics and laws of melon slices. TheR2 ranged from 0.992 9~0.999 9,χ2 ranged from 9.55×10-6~1.51×10-3, RMSE ranged from 0.002 68~0.027 47. The predicted values of Thompson equation were similar to the true ones,R2 was 0.995 0,χ2 was 3.93×10-4, and RMSE was 0.016 58.Conclusion:The model can be used to predict the moisture variation during the dry-hot air drying of melon slices.

Abstract:Objective:Improve the quality of dried okra products.Methods:The rehydration ratio, shrinkage rate, vitamin C content, drying time and sensory score were used to analyze the effects of different pretreatment methods on the quality of dried okra products, and the coefficient of variation method was used for comprehensive weighted evaluation.Results:The results showed that blanching and ultrasonic pretreatment can significantly increase the rehydration ratio of the dried sample (P＜0.05). The shrinkage rate was most affected by blanching. The vitamin C content of the pretreatment group was lower than that of the control group, and the ultrasound treatment group had the least loss. The blanching and ultrasonic pretreatment can shorten the drying time, and sensory scores of samples pretreated by ultrasound and color protection were significantly higher than those pretreated by blanching (P＜0.05). The comprehensive evaluation by the coefficient of variation method showed that the quality of the okra pretreated by ultrasonic was the best, followed by the color protection treatment, and the blanching treatment had the lowest comprehensive score. When the ultrasonic pretreatment temperature was 20 ℃, the comprehensive score of the dried sample obtained was the highest, which was 0.907.Conclusion:The research showed that the ultrasonic pretreatment was a better pretreatment method with hot air drying of okra.

Abstract:Objective:In order to resolve a lot of redundant information and low precision of apple internal quality evaluation existed in apple near infrared spectroscopy, improving the precision of apple internal quality evaluation.Methods:A new apple inner quality evaluation model based on deep belief network (DBN) and grey wolf optimization algorithm was proposed. According to the characteristic of high dimension and complexity of apple spectral data, the method of selecting characteristic wavelengths of apple spectral data was determined by comparing the results of selecting characteristic wavelengths of full-band, principal component analysis and continuous projection. The parameters of DBN model were optimized by GWO Algorithm, and a continuous projection method for feature wavelength selection and GWO-DBN model for apple inner quality evaluation were proposed.Results:Compared with PSO-DBN, GA-DBN and DBN, the accuracy of apple inner quality evaluation based on GWO-DBN was the highest.Conclusion:This algorithm can effectively improve the accuracy of apple inner quality evaluation and provide a new method for apple inner quality evaluation.

Abstract:Objective:This study aimed to explore the best parameters of buckwheat noodle composite preformed powder.Methods:Single factor experiment, multi-index comprehensiveevaluation method and orthogonal experiment were used to optimize the special composite preformed powder recipe of buckwheat noodles.Results:The best parameters of buckwheat noodle composite preformed powder were 45% of buckwheat flour, 8% of modified starch, 1.2% of compound phosphate and 3% of gluten powder. In this situation, the tensile area of composite flour dough was 3 378.6 g·mm; the stabilization time was 7.23 min, the content of wet gluten was 23.71%; the sensory score was89.2; the comprehensive score of multiple indexes was 0.926 5.Compared to the groups of single factor test and orthogonal test, the quality of composite powder in each test group was significantly improved (P＜0.05), and its application in non-fried instant noodles had a good effect. Conclusion:The optimized composite powder can be used as the raw powder of various kinds of noodles, such as buckwheat coarse grain noodles, semi-dry noodles and new-type non-fried coarse cake.

Abstract:Objective:In order to study the optimal enzymatic hydrolysis process conditions of corneum galli gigerii endothelium, and analyze the amino acid composition, molecular weight distribution and antioxidant activity of the enzymatic hydrolysate.Methods:With the yield of polypeptide and the degree of hydrolysis as indicators, the orthogonal experiment was used to optimize the enzymatic hydrolysis conditions of corneum galli gigerii endothelium. Amino acid analyzer and high-performance gel permeation chromatography were used to determine the amino acid composition and molecular weight distribution of the enzymatic hydrolysate of corneum galli gigerii endothelium. The clear ability of corneum galli gigerii endothelium to DPPH free radicals and ABTS+radical were also investigated.Results:The results showed that the optimal enzymatic hydrolysis conditions of corneum galli gigerii endothelium were as follows: co-enzymatic hydrolysis with neutral protease and alkaline protease, enzymatic hydrolysis temperature at 60 ℃, enzymatic hydrolysis for 9 h at pH 11, and cooking time for 6 h. Under the control of these conditions, the yield of polypeptide was 75.68%, and the degree of hydrolysis was 14.43%. The ratio of the essential amino acid to the non-essential amino acid of the enzymatic hydrolysate was58.56%, which has high nutritional value. The proportion of enzymatic hydrolysate with a relative molecular mass of ＜1 000 Da accounts for 90.2%, which was easy to be digested and absorbed. When the concentration of the enzymatic hydrolysate was1.5 mg/mL, the scavenging rate of ABTS+free radicals reached 94.19%.Conclusion:Using the optimal enzymatic hydrolysis process strategy, the yield of corneum galli gigerii endothelium polypeptide is as high as 75.68%, and it has good antioxidant activity.

Abstract:Objective:Collagen was extracted from the skin of Micropterus salmoides and used to explore the effect of enzyme types on the antioxidant activity of collagen peptides.Methods:Four kinds of enzymes were used, namely alkaline protease, neutral protease, papain and trypsin. The enzymatic hydrolysis of collagen Alkaline protease enzymatically hydrolyze collagen peptide (APP), Neutral protease enzymatically hydrolyze collagen peptide (NPP), Papain enzymatically hydrolyze collagen peptide(PP), Trypsin hydrolysis of collagen peptide(TP), were obtained and compared their total antioxidant activity, including reducing activity, DPPH, ·OH and O-2·free radical scavenging ability, ferrous ion chelating ability and lipid Oxidation inhibitory activity.Results:Four kinds of proteases enzymatically hydrolyze collagen peptides all have antioxidant activity, and the antioxidant capacity was positively correlated with the concentration of collagen peptides. Among them, APP has the best antioxidant activity. The total antioxidant activity and reducing activity respectively were 1.725 and 0.958, and the scavenging rates for DPPH and O-2·radical respectively were 56.35% and 38.41%, respectively.Conclusion:The collagen peptides hydrolyzed by alkaline protease have better antioxidant activity.

Abstract:Objective:The research is to explore the enzyme inhibition of Perilla crude extract, and to preliminarily elucidate the pharmacological substance basis of them on hyperglycemia, hyperuric acid and hyperlipidemia.Methods:The content of flavonoids and phenolic acid in UV extract was determined and showed the active components associated with enzyme inhibition. In vitro experiments, the inhibition of Perilla extracts on different enzyme activity was determined and the inhibitory activity was evaluated by IC50. Molecular docking was used to predict the targets of Perilla crude extract on pancreatic lipase and amylase inhibition.Results:Flavone content in the crude UV extract was 0.309 8 mg/mg, and the total phenolic acid content was 58.59 mg/g. The IC50 values of Perilla crude extractd for α-amylase, xanthine oxidase, pancreatic lipase and acetylcholinesterase were 0.273, 0.244, 0.347 and 0.018 mg/mL, respectively.Apigenin-5-O-β-D-glucosine, xyrhinin-7-diglucosotide, apigenin-7-glucosine, cannol-3-O-ruassin, rosemary acid, rutin and others were the effective active components of perilla crude extracts.Conclusion:The Perilla crude extracts all have certain inhibitory activities on four enzymes, and presents a dose-effect relationship.

Abstract:Objective:This study aimed to compare the effects of different extraction methods including cold pressing extraction, soxhlet extraction and subcritical butane extraction on the yield, physicochemical properties, fatty acid composition and in vitro antioxidant activity of elderberry seed oil.Methods:Elderberry seed oils were extracted from elderberry seed by cold pressing extraction, soxhlet extraction and subcritical butane extraction. The physicochemical parameters and in vitro antioxidant activity of oil were determined with reference to national standards, and the fatty acid composition was analyzed by GC-MS.Results:Among the three extraction methods, the highest oil yield was obtained by subcritical butane extraction (28.8%), followed by soxhlet extraction (27.6%) and cold pressing extraction (18.8%). The acid value and peroxide value of elderberry seed oil obtained by subcritical butane extraction were the lowest, and its iodine value was the highest, compared to other methods. The fatty acid composition of elderberry seed oils obtained from the three extraction methods were similar, mainly including linolenic acid, linoleic acid and palmitic acid, whereas the contents were different, with the highest linolenic acid content (46.94%) in the elderberry seed oil obtained by subcritical butane extraction. The elderberry oils obtained by three extraction methods had good antioxidant activity, and the elderberry oils obtained by subcritical butane extraction had the strongest scavenging ability of DPPH free radicals and ABTS free radicals.Conclusion:Different extraction methods had certain influence on the quality of elderberry seed oil, and subcritical butane extraction had good effect on extraction rate and quality of elderberry seed oil, which was an ideal method for the extraction of elderberry seed oil.

Abstract:Objective:The aim of this study was to improve the quality of Nongxiang flavor crude Baijiu.Methods:The effect of advancd removing Huangshui fluid in on the quality and yield of crude Baijiu was studied in multi-grain traditional Baijiu at different times during the cellar fermentation cycle.Results:When Huangshui fluid was removed at the 40th day of cellar fermentation of distilled alcoholic fermentative material, compared to the control group at 60th day, the yield of the crude Baijiu was higher (P＜0.05), and the high quality ratio of crude Baijiu, ethyl hexanoate content and ethyl hexanoate/ethyl lactate in superior crude Baijiu were significantly increased (P＜0.05). However, the content of the acetaldehyde and the higher alcohol of the crude Baijiu were significantly decreased (P＜0.05).Conclusion:The optimal time of advanced removing Huangshui fluid was at the 40th day of cellar fermentation of distilled alcoholic fermentative material. This study provides a new approach for improving the quality of Nongxiang flavor crude Baijiu by solid-state fermentation.

Abstract:Objective:The purpose of this study was to mix rice and proso millets and obtain high nutritional value, fantastic taste and flavor mixed rice.Methods:By adding different proportions of proso millets to rice, the nutritional value and fantastic taste of mixed rice were evaluated via the amino acid score (AAS), texture profile properties, sensory evaluations and flavor properties.Results:There were significant differences in the texture profile properties, sensory evaluations and flavor properties among cooked proso millets additions. The proportion of the cooked rice addition was significantly positively correlated to the gumminess and chewiness of rice, while it was significant negatively related to the sensory evaluations. Furthermore, the addition of the proso millets increased the variety, content of flavor compounds in mixed rice and obviously improved the scores of the sensory evaluations.Conclusion:The integral quality and nutritional value of the mixed rice were the most excellent when the addition of the Yushu 1 proso millet was 10%~20%.

Abstract:Objective:This study aimed to explore the best parameters of buckwheat noodle composite preformed powder.Methods:Single factor experiment, multi-index comprehensiveevaluation method and orthogonal experiment were used to optimize the special composite preformed powder recipe of buckwheat noodles.Results:The best parameters of buckwheat noodle composite preformed powder were 45% of buckwheat flour, 8% of modified starch, 1.2% of compound phosphate and 3% of gluten powder. In this situation, the tensile area of composite flour dough was 3 378.6 g·mm; the stabilization time was 7.23 min, the content of wet gluten was 23.71%; the sensory score was89.2; the comprehensive score of multiple indexes was 0.926 5.Compared to the groups of single factor test and orthogonal test, the quality of composite powder in each test group was significantly improved (P＜0.05), and its application in non-fried instant noodles had a good effect.Conclusion:The optimized composite powder can be used as the raw powder of various kinds of noodles, such as buckwheat coarse grain noodles, semi-dry noodles and new-type non-fried coarse cake.

Abstract:The development of food infrared heating theories were discussed in this review, and the advancement of infrared heating in food processing were summarized. Moreover, the principle of food processing and process optimum method in various food infrared thermal treatment technologies, including sterilizing, thawing, blanching, baking, peeling and drying processes were also discussed.

Abstract:This paper reviews the exogenous additives such as microorganisms, enzymes and excipients currently applied to cigar tobacco leaf fermentation and their research and application results to improve the quality of tobacco leaves, and prospects the research direction of cigar tobacco industrial excipient fermentation.

Abstract:In this paper, the research on the active components, dry processing methods, extraction of functional components and processed products of Flos Lonicerae at home and abroad in recent years were summarized and discussed, and the development direction of Flos Lonicerae in the future was prospected.

Abstract:The research progress on determination of freebase nicotine in tobacco and tobacco products in the past 30 years was reviewed and discussed, including solvent extraction method, headspace solid-phase microextraction method,1H NMR, Henderson-Hasselbalch method and spectroscopy method, etc. Advantages and limitations of each method were summarized and discussed and the development in this field was prospected.