Abstract:Objective: The adsorption performance and mechanism of Xanthoceras sorbifolia shell biochar activated by phosphoric acid for methylene blue was investigated in this study. Methods: With phosphoric acid as activator, the Box-Behnken center combination design was used to optimize the preparation conditions of biochar from Xanthoceras sorbifolia shell. The biochar obtained under the optimal preparation conditions was used to adsorb methylene blue in water. Through investigating the adsorption influencing factors, the adsorption characteristics of biochar on methylene blue were determined, and combined with the analysis of kinetic, the adsorption mechanism was discussed. Results: The optimum technological conditions for preparing biochar from Xanthoceras sorbifolia pericarp by phosphoric acid activation were as follows: impregnation ratio （m_{Pericarp powder}∶m_{Phosphoric acid solution}） 1∶21, pyrolysis temperature 530 ℃ and pyrolysis time 75 min. The optimal conditions for adsorption of methylene blue in water by sorbent biochar from Xanthoceras sorbifolia shell are as follows: initial pH of solution 12.6, dosage of biochar 1.0 g/L, initial mass concentration of methylene blue 200 mg/L, and adsorption equilibrium time 120 min. The adsorption of Xanthoceras sorbifolia shell biochar on methylene blue in water obeys the quasi second order reaction kinetics. The adsorption process consists of three stages: liquid film diffusion control, pore diffusion control and adsorption desorption equilibrium. Conclusion: Phosphoric acid activation can significantly increase the specific surface area and pore volume of sorbent biochar from Xanthoceras sorbifolia sheell, thereby significantly improving its adsorption capacity for methylene blue.

Abstract:Objective： Optimize the preparation process of salt-soluble porcine liver protein and improve the utilization rate of porcine liver by-products. Methods： Taking the extraction rate as the index, the effects of NaCl concentration, pH, extraction time and solid-liquid ratio on the extraction rate of SSLP were analyzed, and the optimal preparation process was determined by orthogonal rotation optimization test. Taking water soluble liver proteins （WSLP） as the control, the functional characteristics （solubility, foaming, foam stability, emulsification, emulsification stability, etc.） of SSLP were compared and analyzed, and Fourier transform infrared spectroscopy （FT-IR） was used, the structural changes were analyzed by low field nuclear magnetic resonance （LF-NMR） and differential scanning calorimetry （DSC）. Results： The optimum extraction process of SSLP was NaCl concentration 0.4 mol/L, pH 8, extraction time 12.95 h, solid-liquid ratio 1∶4.6 (g/mL), and the extraction rate was 10.60%. FT-IR analysis showed that the absorption peak of characteristic functional groups of SSLP was obvious and in the secondary structure β-The relative content of corner was 39.91%, α-The relative content of helix was 13.55%, β-The relative content of folding was 21.32%, and the relative content of random curl was 25.23%; LF-NMR analysis showed that SSLP had higher bound water and higher water retention; DSC results showed that the denaturation temperature of SSLP was 78.68 ℃. Conclusion： SSLP prepared under optimal process conditions has better solubility, foaming, emulsification and emulsification stability than WSLP, which is a high-quality source for the development of pig liver protein products.

Abstract:Objective: This study aimed to explore the optimum addition of buckwheat flour in buckwheat Chinese leavened pancakes. Methods: Farinograph, extensograph and viscometer were used to investigated the effects of different buckwheat flour additions on the rheological properties of the mixed flour dough. The hardness, gumminess and chewiness of the Chinese leavened pancake were measured by texture analyzer. The sensory quality of the Chinese leavened pancake was evaluated by the sensory evaluation score. Results: Adding 0~40% buckwheat flour to the flour, the rheological properties of the mixed flour dough became significantly worse with the increase of buckwheat flour content. The water absorption rate, development time and farinograph quality number of the mixed flour dough decreased gradually. When the addition of buckwheat flour was 40%, the farinograph quality number decreased by 69.1%, and the development time decreased by 70.7%. The extensibility and extensigram curve area of mixed flour dough decreased gradually with the increase of buckwheat flour content, and the extension resistance increased first and then decreased. When the addition of buckwheat flour was 20%, the hardness, stickiness and chewiness of the Chinese leavened pancakes were the lowest, and the sensory score was the highest, which increased by 19.4% compared with the blank control. Conclusion: The addition of buckwheat flour reduces the quality of the mixed flour, but an appropriate amount of buckwheat flour can impart a special flavor and nutritional value to the Chinese leavened pancakes. The rheological properties of the mixed flour and the quality of the Chinese leavened pancakes added within 20% are better.

Abstract:Objective: Standardize the use of phoxim to ensure the safety of aquatic products. Methods: Taking freshwater crucian carp as the research object, Selecting phoxim, an organic phosphorus pesticide often used in agriculture, as the representative of exogenous environmental pollutants. The changes in normal physiological metabolism of crucian carp exposed to phoxim were studied by using the ¹H-NMR metabonomics method combined with PCA, PLS-DA, OPLS-DA and other multivariate statistical methods. Based on this, the toxic effects of phoxim on crucian carp and the toxicological mechanism of phoxim in the crucian carp were deduced. Results: Compared with the control group, the metabolites in the crucian carp serum sample of the phoxim group have a significant increase in concentration of 3-HB, glucose and phenylalanine, and a significant decrease of glutamic acid, alanine, asparagine, histidine, lactic acid, glycerol phosphate of choline, phosphoric acid, choline, choline and unsaturated fatty acids, lipids, guanine nucleoside, inosine(P<0.05). Conclusion: The results showed that phoxim can change amino acid metabolism, energy metabolism, disturbance of neurotransmitter balance and oxidative stress in crucian carp.and the endogenous metabolites change may be related to Ⅱ metabolic reactions of phoxim in crucian carp.

Abstract:Objective: Preferred biomass hydrolysis for preparation of arabinose and its kinetic analysis during the hydrolysis process. Methods: Single factor experiment and response surface methodology were used to optimize the conditions for the preparation of arabinose from gum Arabic by dilute acid hydrolysis, and the kinetics of the hydrolysis process was studied. Results: The optimum hydrolysis conditions were as follows: reaction time 237 min, sulfuric acid concentration 0.16 mol/L, reaction temperature 91 ℃. Three parallel experiments were carried out under these conditions. The average concentration of L-arabinose in the hydrolysate was 35.45 g/L. The kinetic parameters of arabinose formation and degradation were obtained by Saeman model fitting. The hydrolysis of Arabic gum is an internal diffusion controlled reaction process. Conclusion: The hydrolysis process of gum Arabic is a continuous pseudo homogeneous first-order reaction process, and the Saeman model can better describe the hydrolysis process of gum Arabic to arabinose.

Abstract:Objective: This study aimed to investigate the antioxidant properties of wheat germ protein glycosylation product. Methods: The glycation product (WGP-G) of wheat germ protein (WGP) and glucose was prepared by ultrasonic assisted moist heat method. Different ultrasonic time (10, 20, 30, 40, 50 and 60 min) and reaction temperature (70, 80 and 90 ℃) were measured. The browning degree, grafting degree, reducing power, hydroxyl radical scavenging capacity, superoxide anion radical scavenging capacity, DPPH radical scavenging capacity and ABTS+ radical scavenging capacity of WGP-G at 90 ℃ were evaluated comprehensively. Results: The browning degree of WGP-G increased with the increase of ultrasonic time and reaction temperature. The grafting degree, reducing power, hydroxyl radical scavenging ability, superoxide anion radical scavenging, DPPH radical scavenging ability and ABTS⁺ radical scavenging ability all increased with the increase of reaction temperature, but showed a trend of first increasing and then decreasing with the extension of ultrasonic time. Conclusion: The antioxidant properties of WGP-G were affected by ultrasonic time and reaction temperature.

Abstract:Objective: This study aimed to investigate the pollution of heavy metals in Astragalus membranaceus in the main producing areas of Gansu, and to evaluate the potential health risks of edible Astragalus membranaceus. Methods: The contents of five heavy metal elements Pb, Cd, As, Hg and Cu in Astragalus membranaceus were determined by inductively coupled plasma mass spectrometer （ICP-MS） by random sampling method, and the data were analyzed. Estimated Daily Intake （EDI）, Target Hazard Factor （THQ） and Lifetime Carcinogenicity Risk （LCR） were used for health risk assessment. Results: The average contents of Pb, Cd, As, Hg, and Cu elements in 58 batches of Astragalus membranaceus samples were 0.148, 0.024, 0.139, 0.011 and 4.569 mg/kg, respectively. According to the limited standards stipulated in the 2020 edition of the Chinese Pharmacopoeia, although the detection rate of individual elements was high, but none of them exceeds the standard. The health risk assessment model showed that EDICu>Pb>Hg>Cd, and all less than 1, LCR was also less than 1×10^-6. Indicated that the overall level of Astragalus membranaceus samples in this study was safe. Conclusion: The content of five heavy metals in Astragalus membranaceus produced in Gansu will not cause potential risks to the health of adults and children, and there is no potential carcinogenic risk.

Abstract:Objective: A COI sequence-based full-length DNA barcoding technology was established to identify adulteration of seven animal-derived components （including pigs, cows, sheep, chickens, ducks, geese and rabbits） in edible blood products. Methods: After the blood products were extracted and purified by DNA extraction and PCR amplification, the clone sequencing results were submitted to the DNA barcode local database of the 7 blood products for sequence comparison. The pretreatment method, DNA extraction method and PCR amplification conditions of the blood products were also selected and optimized, and various common blood product adulteration models were established to study the lowest adulteration detection rate of the models. Results: The results showed that the DNA amplification efficiency of seven edible blood products was 100%, and the minimum adulteration detection rate in various adulteration models was 5%; 25 batches of commercially available edible blood products were identified as adulterated using the method, and 21 batches were found to be adulterated with other animal-derived ingredients. Conclusion: The method is simple, reliable and can be used as a testing method for daily quality supervision of edible blood products.

Abstract:Objective: It was the method of evaluating regional food safety status through food safety evaluation index model. Methods: In the index model, various factors affecting food safety, such as the size of the city, the types of food, the hazards of the test items, the place of production, etc., were comprehensively considered, and a variety of data sources were used to support the model. Using this model, the results of food safety index could be calculated from multiple angles and different levels, such as region, food category, region and food category. Results: Sampling data of Guangxi food safety assessment in 2021 had been utilized for empirical research. The classic large sample estimation method and empirical Bayesian estimation method had been applied for model calculation. It was found that the results from these two methods had a certain differences, but both methods got the same results showing that restaurant and catering food safety was significantly poorer than other food categories. In addition, the Bayesian estimation method could effectively solve the calculation problem when the pass rate was 100% or the values were largely close. Conclusion: The model could calculate the food safety index results from multiple angles and different levels, such as regions, food types.

Abstract:Objective: This study aimed to investigate the residues and risk assessment of pesticides in peach gum. Methods: The quantitative analysis of 44 pesticide residues in peach gum was established based on liquid chromatography tandem-mass spectrometry （LC-MS/MS）, and the pesticide residues in 173 peach gum samples were detected as well as the risk assessment of pesticide residues. Results: The limits of detection （LOD） and the limits of quantification （LOQ） of 44 kinds of pesticides in this quantitative method were between 0.05~1.80 μg/kg and 0.20~2.42 μg/kg, respectively. Recoveries of these pesticides ranged from 61.77%~119.48%. In 173 peach gum samples, 22 out of 44 pesticides were detected and the total detection rate of pesticides in peach gum was 98.8%. The detection rate of difenoconazole was the highest （95%）, followed by chlorpyrifos （54%）, carbendazim （34%）, furamethoxam （32%） and pyraclostrobin （19%）. The average residue of difenoconazole in different peach gum samples was the highest （0.332 mg/kg）, followed by furamethoxam （0.093 mg/kg）, carbendazim （0.061 mg/kg） and chlorpyrifos （0.033 mg/kg）. Conclusion: Pesticide residues in peach gum were related to the usage of pesticides in peach production and were at a low risk level. It is recommended to pick peach gum from August to October.

Abstract:Objective: This study aimed to establish the methods for determining the content of sodium hyaluronate in solid drinks by reversed-phase high performance liquid chromatography. Methods: With sodium hyaluronate content as evaluation index, after the sample extract was precipitated by ethanol, hyaluronase was used to hydrolyze the precipitate. The optimal enzymolysis conditions obtained by single factor test and orthogonal test were as follows: enzymolysis, at 34 ℃ and pH 6.5, for 120 min. The determination was performed on Uliumate C₁₈ (4.6 mm×250 mm,5 μm) column with mobile phase: acetonitrile 10 mmol/L sodium octane sulfonate solution (V_acetonitrile∶V_{octane sulfonate} =10∶90) at flow rate of 0.6 mL/min. The detection wavelength was 232 nm and quantified by external standard method. Results: The correlation coefficient of sodium hyaluronate was 0.999 9. The recoveries of samples were between 96.1%~101%, and the relative standard deviation was 3.16%. The determination of limit was 0.062 g/kg. Conclusion: Ethanol precipitation combined with enzymolysis-reversed phase chromatography has strong specificity, high accuracy, good repeatability and less interference, which is suitable for the determination of sodium hyaluronate in solid drinks.

Abstract:Objective: This study aimed to optimize the performance of heat pump system and discuss the optimal exhaust pressure of carbon dioxide system under the control of different working conditions. Methods: By establishing a CO₂ trans-critical heat pump model, the relationship between exhaust pressure and heat production, inspiratory superheat, refrigerant mass flow rate and system energy efficiency was analyzed, and the influence of inlet and outlet water temperature and ambient temperature on the optimal exhaust pressure was deeply studied. Moreover, the reliability of the model was verified by the CO₂ heat pump test bench. Results: At the three effluent temperatures, the heat production increased with the increase of exhaust pressure, and the mass flow rate decreased with the increase of exhaust pressure. The cycle performance coefficient and superheat showed a trend of first increasing and then decreasing with the increase of exhaust pressure, the optimal exhaust pressure increased with the increase of inlet and outlet water temperature and ambient temperature, but the increase of inlet and outlet water temperature reduced the system cycle performance coefficient. Based on this, the optimal exhaust pressure correlation formula at the outlet temperature of 60 ℃ was fitted, and five groups of tests were designed to prove its reliability. Conclusion: The optimal exhaust pressure of the system is determined by a large number of simulation data, and compared with the test values, it is found that the error values are less than 5%, which meets the test and design requirements.

Abstract:Objective: To solve the problem that the thickness and tightness of the rhizopus brick by traditional mechanical stamping JIUQU starter press were different, so as to achieve the effect of manual trampling on the liquor. Methods: Through the analysis of the existing JIUQU starter press machine in the distillery, the transmission mechanism of the mechanical stamping JIUQU starter press machine was optimized, the original crank connecting rod mechanism that controlled the movement of the JIUQU starter die was replaced by the groove cam mechanism, and the cam profile curve was inversely calculated according to the relationship between the JIUQU starter press force and the compression amount of the JIUQU starter press material, and the eleventh degree polynomial cam profile curve that conforms to the compression deformation of the JIUQU starter press material was constructed. Results: Compared with the original mechanism, it can reduce the movement time of non working stage by 75.09% and increase the movement time of working stage by 192.60%. Conclusion: After the optimization design, the JIUQU starter press force is matched with the compression amount of JIUQU starter and the effect of the optimal of best JIUQU starter press is achieved.

Abstract:Objectives: To meet the requirements of high cleaning rate and low loss rate. Methods: A small negative pressure winnowing machine for walnut shell and kernel mixtures was developed. Single factor test and response surface optimization method were used to analyze the working parameters of winnowing machine based on such two separation effect indicators as cleaning rate and loss rate. Results: For 1/2 shell kernel, 1/4 shell kernel, 1/8 shell kernel and 1/16 shell kernel materials, the optimal feeding rates were 4.0， 3.5， 3.0， 2.5 kg/min, the fan frequencies were 40， 35， 30， 30 Hz, the feeding inlet heights were 400， 400， 300， 300 mm, respectively. It was seen from the separation effect of different grades of walnut shell materials that 1/2 and 1/4 shell kernel materials had the best separation effect. Conclusion: Shell and kernel separation can be effectively realized by controlling the working parameters of winnowing machine. It is difficult to separate 1/8 and 1/16 shell kernel materials for the overlapping range of suspension speed of shell and kernel materials.

Abstract:Objective: This study aimed to improve the accuracy and feeding speed of the cap arranging unit. Methods: Using SolidWorks to build a virtual model and manufacture a real object, and the kinematic simulation of bottle cap and capping machine was carried out in Adams. Moreover, the results of different speeds were compared and analyzed. ANSYS Workbench was used to carry out engineering simulation of the device components and obtain their natural frequency and vibration mode, and the structural performance was optimized. Results: The cap arranging unit had the minimum damage to the caps at the optimum speed. The optimal speed of the designed new cap sorter mechanism was 15 r/min, and the average number of caps unscrambling was 402 pieces/min. Conclusion: The operation of the new cap sorter mechanism exceeds the scheduled workload stably, which meets the operation requirements of the cap sorter mechanism.

Abstract:Objective: To solve the problems of poor recognition accuracy and low efficiency of existing automatic recognition methods for packaged food. Methods: Based on the automatic identification system of packaged food, an improved YOLOv3 model was proposed for the automatic identification of soft packaged food. The Kmeans++algorithm was introduced into the model to solve the problem of small target insensitivity, the Mish activation function was introduced into the model to improve the accuracy of recognition, and the attention mechanism Senet was introduced into the model to improve the ability of feature extraction. The performance of the recognition model was analyzed through experiments, and the superiority of the model was verified. Results: Compared with the conventional recognition methods, the proposed method can more accurately and efficiently realize the automatic recognition of flexible packaging food, the recognition accuracy rate was 95.40%, and the recognition efficiency was 23.80 f/s, which meets the needs of packaging food recognition. Conclusion: By optimizing the existing food recognition model, the performance of the recognition model can be effectively improved.

Abstract:Objective: To explore the theoretical relationship between interactive availability thinking in the design of nutrition labels for prepackaged foods； To improve consumer awareness and trust, guide consumers' healthy choice behavior, and construct a design framework for prepackaged food labels based on interactive availability model. Methods: Based on the two-tier result model of interactive availability and the empirical evidence of knowledge, this paper analyzes how the design can help the nutrition labels of prepackaged food to effectively convey information and improve the labels' value and its guidance role. Results: Four interactive design strategies were proposed: enhancing the influence of unconscious interaction intention between consumers and food nutrition labels, improving the information awareness of consumers and food nutrition labels through multiple channels, constructing the unconscious public concept mechanism between consumers and food nutrition labels, and constructing the interaction mode of consumer value cognition. Conclusion: Interactive availability is helpful to explore how to improve the practical value of nutrition labeling of prepackaged foods under the interdependence of consumers and prepackaged food nutrition labels, and achieve the expectation of guiding the healthy dietary habit of consumers via nutrition labels.

Abstract:Objective: The research aimed to reveal the changes of biogenic amines in cheese made from different refrigerated milk during ripening and evaluate its quality safety. Methods: The hard cheese made from yak milk refrigerated for 24, 48 and 72 hours was taken as the research object, and the biogenic amines in cheese during ripening were determined by high performance liquid chromatography. Results: During the ripening period from 0 to 6 months, the content of biogenic amine in hard cheese made from different refrigerated yak milk showed an increasing trend. When the cold storage time of yak milk was extended from 24 h to 72 h, total biogenic amines, 2-phenylethylamine, cadaverine, tyramine and putrescine in cheese also increased in turn. The biogenic amines in the cheese made from raw milk refrigerated for 72 hours after ripening for 4 months were significantly higher than those in the other two groups of cheese. The contents of total biogenic amines and tyramine yak milk hard cheese matured for 6 months were （212.94±8.03） mg/kg and （81.04±3.92） mg/kg respectively. Conclusion: With the prolongation of the cold storage time of raw milk and the ripening time of cheese, the biogenic amine content in cheese increased. However, when the cold storage time of raw milk was less than 72 h, the biogenic amine content in its cheese was lower than the content recommended by scholars.

Abstract:Objective: This study aimed to investigate the effect of cold storage temperature on the quality of plant-based bacon. Methods: The effect of cold storage temperature (-40, -20, 4 ℃) on texture characteristics, cooking loss, water activity, protein content, total number of colonies and microstructure of plant-based bacon were investigated, and the optimal cold storage conditions of plant-based bacon were explored. Results: During the period of refrigeration (0~30 d), the hardness, cooking loss rate and number of microorganisms of plant-based bacon increased, while the water activity decreased with the extension of refrigeration time. As refrigerated temperatures dropped, the plant-based bacon became more structurally stable and lose less water, retaining a higher percentage of protein and a lower microbial population. Conclusion: The optimum refrigeration temperature of plant-based bacon is -40 ℃.

Abstract:Objective: This study aimed to promote the deep development of safflower seed oil. Methods: Taking sterilization rate as an index, safflower seed oil/dragon fruits juice emulsion was treated by different processing distance, voltage and time. Response surface methodology was used to establish the conditions for low temperature plasma （LTP）sterilization of emulsion. The changes of physicochemical indexes (vitamin C and anthocyanin content, particle size and ζ potential, peroxide value and acid value) during storage were compared between thermal sterilization (at 80 ℃ for 20 min) and LTP sterilization. Results: The optimized process conditions of LTP sterilization were treatment distance at 5.1 cm and voltage of 6.4 kV for 151.0 s. Under the control of these conditions, the sterilization rate reached 98.2%. After storage for 20 days, the retention rate of vitamin C and anthocyanin in LTP-treated emulsion was higher than that in heat-treated emulsion, and the particle size was smaller than that in heat-treated emulsion; The ζ potential was higher than that in heat-treated emulsion, and the difference was significant（P<0.05）. However, the difference of peroxide value and acid value was not significant. Conclusion: LTP treatment can not only effectively kill the microorganisms in the emulsion, but also maintain the quality of emulsion better than heat treatment, and the invention relates to a new method for sterilizing the safflower seed oil/dragon fruits juice emulsion.

Abstract:Objective: To explore the changes of the total flavonoids, free amino acids and quercetin extraction amount with the brewing time and temperature during the brewing process of Penthorum chinense Pursh （PCP） leaf tea and fit the extraction kinetics equation of the three and calculate the kinetics parameters. Methods: The total flavonoids, free amino acids and quercetin were determined by ultraviolet spectrophotometry and high performance liquid chromatography （HPLC）. The second-order kinetic model and Arrhenius formula were used to fit the kinetics and calculate the kinetic parameters. Results: The leaching amount of total flavonoids and quercetin increased with the increase of the temperature and the brewing time in the range of 60～100 ℃ for 60 min. When brewing for 60 min at 60~90 ℃, the free amino acids had the same leaching law. When the temperature rised to 100 ℃, the heat loss of free amino acids was large after brewing for 20 min. The second-order kinetic model could fit the leaching amount of the three substances well with the high correlation coefficient. Linear relationship between temperature and second-order rate constant k was good. The activation energies of total flavonoids, free amino acids and quercetin were 16 628.201, 23 415.139 and 14 975.396 J/mol. Conclusion: The extraction amount of total flavonoids, free amino acids and quercetin in PCP leaf tea changed significantly with the brewing time and temperature, and the extraction amount of the three was in line with the second-order kinetic model in the range of 60~90 ℃, which can be used to predict the extraction amount.

Abstract:Objective: This study aimed to investigate the effect of far infrared radiation heating on the oxidase activity and conformation of polyphenol oxidase (PPO) of yam. Methods: By using different far infrared radiation temperatures, the effects of different far infrared radiation temperatures on yam PPO activity, browning degree, total phenol content and PPO conformation were studied. Results: When the radiation temperature is 260 ℃ PPO enzyme is not deactivated after 11 min. When the radiation temperature is higher than 260 ℃, PPO can be inactivated within 3~7 min. However, the browning degree and total phenol content did not change regularly with the increase of radiation temperature and treatment time. After far-infrared pretreatment, the contents of random curling and α-helix changed slightly with the increase of radiation temperature, while β-angle decreased and β-folding increased, indicating that far-infrared radiation changed the secondary structure of PPO. The ultraviolet spectrum of PPO shifted blue and fluorescence spectrum shifted red, indicating that the tertiary structure of PPO changed. Conclusion: Far-infrared radiation heating can change the conformation of yam PPO and eventually deactivate it.

Abstract:Objective: This study aimed to investigate the antioxidation and synergistic effect of flavonoid extract of Zanthoxylum armatum DC. Methods: DPPH radical and ABTS radical scavenging methods were used to evaluate the antioxidant activity of flavonoids extract from Z. armatum, and the synergies of flavonoids extract with vitamin C and rutin complex were studied by adding method. Results: The semi-inhibitory concentrations of DPPH free radical and ABTS free radical IC₅₀ were 0.03 and 0.062 mg/mL, respectively, showing strong antioxidant activity. The antioxidant activity of the complex composed of flavonoid extract and vitamin C or rutin was high, and the antioxidant activity of the complex composed of vitamin C and flavonoid extract was higher than that of rutin and flavonoid extract when the ratio was 1∶1. Conclusion: The flavonoids of Z. armatum have strong antioxidant activity, and their complex composed of vitamin C and rutin can improve the scavenging capacity of DPPH free radical and ABTS free radicals. The extracted flavonoids have antioxidant synergistic effect, and can be used as a potential source of natural antioxidants.

Abstract:Objective: This study provided basic data for the investigation of polysaccharides in coffee and the development of natural active polysaccharides. Methods: The water extraction method and antioxidant activity of green coffee beans polysaccharide (GBP) from Yunnan province. Response surface method was used to optimize the extraction process of polysaccharide from coffee bean. Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) were used to identify and characterize the structure of polysaccharide from coffee bean. DPPH, ABTS free radical scavenging assay and FRAP assay were used to evaluate the antioxidant capacity of coffee bean polysaccharide in vitro. Results: The optimal extraction conditions were as follows: extracting at 59 ℃ for 45 min, liquid-solid ratio (V_W∶m) 21∶1 (mL/g), concentrated volume 1/8 and ethanol volume fraction 75%. Under the control of these conditions, the yield of polysaccharides from coffee beans reached 9.56%. The results of FT-IR and electron microscopy showed that the polysaccharide of coffee bean had irregular pore structure. The DPPH scavenging capacity and ABTS radical scavenging capacity of coffee bean polysaccharide was 2.32 mg/mL (IC₅₀) and 0.011 mmol Trolox/g GBP, respectively. The iron reducing capacity of coffee bean polysaccharide was 0.95 mmol Fe²⁺/g GBP. Conclusion: Polysaccharide derived from green coffee beans is a kind of polysaccharide with irregular pores and antioxidant activity, which is valuable for further research and development.

Abstract:Objective: This study aimed to analyze and compare the quality of four brands of silver cod that have high market sales. Methods: The sensory quality, whiteness, texture and volatile flavor substances of four brands of silver cod were detected by sensory analysis, colorimeter, texture analyzer and gas chromatography-mass spectrometry. Results: Among the four brands of silver cod, BS had the highest sensory score, followed by BI and WH, and ILU had the lowest. BS had the best whiteness, followed by BI and WH, while ILU had the worst. ILU had significantly higher hardness and chewiness than the other three brands, and BS had significantly lower elasticity than the other three brands, and there was no significant difference in the cohesion of the four brands of silver cod. A total of 122 kinds of volatile substances (excluding internal standards) were detected in the four brands of silver cod, of which hydrocarbons, alcohols and esters were at a high level and were the main flavoring substances of cod, accounting for 53, 20 and 17 respectively. 24 kinds of volatile substances detected were found in all four brands, and a total of 85, 63, 53 and 53 volatile substances were detected in ILU, BI, BS and WH respectively, with 40, 6, 10 and 5 kinds of volatile substances unique to each. Conclusion: BS had the best sensory quality and colour but slightly less elasticity, and ILU had the best hardness, chewiness and a significantly better overall flavor than the other three brands. BI, BS and WH were relatively similar in terms of type and content of various volatile flavor substances.

Abstract:Objective: This study aimed to improve the tenderness and flavor content of Yanbian cattle beef. Methods: Rump beef of Yanbian cattle were dry-aged by using three different methods, i.e., Method A: RH（65±5）% aging for 10 days, RH（75±5）% aging for 10 days, and then RH （85±5）% aging for 20 days; Method B: RH（75±5）% aging for 20 days and then RH（85±5）% aging for 20 days; Method C: RH（85±5）% aging for 40 days. The quality changes caused by the different aging processes were then analyzed and compared. Results: The cooking loss of the beef processed by all the three methods increased significantly with the extension of aging time, but the beef loss (39.14%) in Group A was the highest. The TBARS and TVB-N values of group C were 1.387 and 14.833, respectively, significantly higher than those of the other two groups. The fat and protein contents of each group showed an increasing trend, while the shear force value decreased by 50%. No significant difference in the changes of cooking loss rate, color and pH value were found among the groups. The results showed that with dry-aging, the richness of taste attributes was elevated with higher freshness and aftertaste. The bitterness in group B was lower, and the relative content of aldehydes and ketones among volatile flavor compounds was higher. Conclusion: Method B was the best dry-aging process for Yanbian cattle rump beef.

Abstract:Objective: In order to improve the special smell of Camellia oleifera seed oil, the Zanthoxylum flavor Camellia oleifera seed oil was developed with camellia oleifera seed oil and prickly ash as the raw materials. Methods: The peroxide value, acid value, fatty acid composition and odor change of Zanthoxylum bungeanum flavor seed oil were studied under different processing conditions. Results: When the ratio of material to liquid was 10∶100 (m_pepper∶m_{camellia oil}), the frying temperature was 180 ℃, and the frying time was 5 minutes, the acid value, peroxide value and hydroxy-β-pyrroxin content were 0.400 7 mg/g, 0.030 4 g/100 g and 2.225 mg/g, respectively. The ratio of material to liquid had little influence on the content of main fatty acids of Zanthoxylum bungeanum flavor oil tea seed oil. Camellia oleifera seed oil and Zanthoxylum bungeanum flavor oil contain the key flavor compounds (E) -2-octenal and heptanal. Conclusion: The special flavor substances of Zanthoxylum bungeanum oil, linalool and limonene, can effectively change the flavor of the oil.

Abstract:Objective: This study aimed to improve the emulsifying and processing properties of tilapia myofibrillar protein. Methods: The tilapia muscle fibrin (TMP) was modified with galactose oligosaccharide (GOS). The effects of TMP/GOS concentrations, pH values, temperature, time and other technological conditions on the grafting degree, solubility, emulsifying activity and emulsifying stability of TMP-GOS conjugation were investigated. The preparation process of TMP-GOS conjugate was optimized using emulsion stability as response surface. The functional properties of TMP-GOS conjugation were analyzed and verified by endogenous fluorescence spectroscopy, surface hydrophobicity, Fourier infrared spectroscopy and peakering emulsion microscopy. Results: The optimal process conditions were as follows: tilapia myofibrillar protein/ galactooligosaccharides (m_TMP∶m_GOS=1∶1) mass concentration is 27.34 mg/mL, pH value is 11.2, temperature is 79.9 ℃, time is 4.09 h. The emulsifying stability, emulsifying activity and solubility of glycosylated TMP were (90.30±1.44) min, (4.70±0.03) m²/g and (66.09±0.52) %. Compared with before modification, they increased by 112.97%, 62.07% and 129.39% respectively. The glycosylation grafting degree of TMP was 34.17%; The protein hydrolysis degree was large, and the protein structure was expanded; The surface hydrophobicity index decreased by 55.68%. Conclusion: Galactose oligosaccharide can significantly modify the structural properties of TMP and improve the emulsification activity and the solubility of TMP.

Abstract:Objective: Walnut soy sauce was prepared with Aspergillus oryzae as a strain, to explore the functional soy sauce. Methods: Based on the preparation of soy sauce. The nutritional components of soy sauce were determined by using high-performance liquid chromatography, automatic amino acid analyzer and gas chromatography. Components less than 10 kDa were separated by using ultrafiltration. Then the peptide content, ABTS, hydroxyl radical scavenging capacity and DPPH radical scavenging capacity in walnut soy sauce fraction were determined. Results: The total content of 16 amino acids in walnut soy sauce was 4.86 g/100 g, and the content of unsaturated fatty acids accounted for 82.84% of the total fatty acids. The peptide content in the walnut soy sauce component was 6.804 g/100 mL. When the concentration of polypeptide was 3.6 mg/mL, the scavenging ability of ABTS of walnut soy sauce component reached 95.13%, the scavenging ability of hydroxyl radical reached 28.20%, and the scavenging ability of DPPH free radical reached 20.08%. Conclusion: The components of walnut soy sauce has high antioxidant properties and its antioxidant capacity is related to peptide content.

Abstract:Obiective: In the study, corn bran powder was used as raw material, and the cell wall was destroyed by ultrasonic vibration and enzymatic hydrolysis, so that corn bran polysaccharide could be dissolved more fully. Methods: The extracted amount of polysaccharide was taken as the index, response surface test optimization was carried out on the basis of single factor test. And the antioxidant activity of corn bran polysaccharide was determined. Results: The optimal extraction process of corn bran polysaccharide was obtained as follows: mass ratio of cellulase to pectinase 2∶1, enzyme dosage was 2% of the quality of corn bran powder, enzymatic hydrolysis time 50 min, ultrasonic treatment 15 min, and solid-liquid ratio （m_{corn bran powder}∶V_{distilled water}） 1∶15 （g/mL）. At this time, the average amount of extracted corn bran polysaccharide was 23.36 μg/g. The extracted corn bran polysaccharide had a certain total reducing capacity, scavenging DPPH free radical and hydroxyl radical ability, and it increased with the increase of mass concentration, when the mass concentration of corn bran polysaccharide sample was 0.2～1.0 mg/mL. Conclusion: Ultrasound-assisted enzymatic method could extract more polysaccharides than single enzymatic method, and the extract could maintain efficient antioxidant capacity.

Abstract:Food-derived bioactive peptides play an immunoregulation role by regulating signal pathways and influencing the expression of cytokines in vivo. This review summarizes immunoregulatory effects of the food-derived protein hydrolysates and bioactive peptides on cells, animal models and human beings, and the immune mechanism of food-derived bioactive peptides in different models is explained. Finally, the future application of bioactive peptides is prospected.

Abstract:Cereals and cereal-based products are easily polluted by mycotoxins in all aspects of production, storage and transportation, and mycotoxins are difficult to prevent due to their variety, low concentration, strong toxicity andlarge difference in nature. This paper summarizes the new development of the pretreatment technologies （liquid-liquid extraction, solid-phase extraction, QuEChERS, immunoaffinity chromatography） and detection technologies （immunochromatography technology, optical spectrum technology, liquid chromatography and liquid chromatography-mass spectrometry） of mycotoxins in cereals and products. The development trend of mycotoxin detection technologies was also prospected.

Abstract:Milk fat globule （MFG） is secreted by mammalian glands and composed of a triacylglycerol core enclosed by a complex triple membrane structure, referred as the milk fat globule membrane （MFGM）. MFGM contains complex lipids and proteins, with nutritional, immunological, neurological and digestive functions. However, the relationship between functions and gastrointestinal digestion and the factors that influence the gastrointestinal digestion of milk fat have not been fully studied. In this paper, the structure composition, functional characteristics, gastrointestinal digestion and the factors affecting the digestion and absorption of milk fat were reviewed in order to provide an insight for the research on the digestion of infant formula.

Abstract:Cicada flower is a valuable edible and medicinal mushroom. Polysaccharides are the most important active ingredients of cicada flower. This paper reviewed the extraction, separation and purification technologies of cicada flower polysaccharides in recent years. Also, it analyzed the biological activities of cicada flower polysaccharides, such as antioxidant, anti-tumor, immune regulation, bacteriostasis, hypolipidemic, hypoglycemic, anti-virus and ease pain. Moreover, the development and application of products were summarized and the existing problems and future research directions were also discussed.

Abstract:Alternaria mycotoxins are the secondary metabolites of Alternaria species, which have obvious toxicity （mutagenicity, teratogenicity and carcinogenicity, etc） to humans and animals. Alternariol （AOH）, alternariol monomethyl ether （AME）, alternuene （ALT）, tenuazonic acid （TeA） and tenoxin （TEN） are the most studied at present. Alternaria mycotoxins was reported in apples, orange, tomatoes, corns and other agricultural products. Eating these foods contaminated by Alternaria mycotoxins will cause serious harm to human health. In this paper, the pollution status and the detection technology of Alternaria mycotoxins were summarized, and the future research direction of Alternaria mycotoxins was prospected. The purpose was to provide references for the risk assessment, detection and prevention of Alternaria mycotoxins in foods.

Abstract:Almond oil is a functional vegetable oil obtained from apricot kernel by pressing, extracting and other technologies, which has the effects of anti-oxidation, anti-inflammation, anti-tumor and prevention of cardiovascular diseases. In this review, the extraction process, nutritional composition and health effect of almond oil were summarized, and the future development tendency of almond oil was prospected.