Abstract:This review summarized the species, preparation methods and biological activities of food-derived functional peptides, and predicted the future research direction and good application prospects of food-derived functional peptides.

Abstract:The grafting degree, surface hydrophobicity, ultraviolet spectrum, fluorescence spectrum and sensitization of glycosylated ovalbumin modified by different hexoses were studied. The results showed that galactose-modified ovalbumin had the highest degree of glycosylation and the lowest fructose modification; the glycosylation reaction reduced the surface hydrophobicity of ovalbumin. UV and fluorescence conformational characterization showed that heat treatment during glycosylation, and the change of molecular group destroyed the original conformation of ovalbumin, with exposing the aromatic amino acid, and the highest degree of destruction of ovalbumin conformation by galactose. The glycosylation reduced the allergenicity of ovalbumin, while the binding capacity of fructose-modified ovalbumin IgG/IgE decreased slightly, which was much lower than that of galactose and glucose.

Abstract:Indirect competition ELISA, high performance liquid chromatography and other techniques were used to study the sensitization and structural changes of glycosylated pollock albumin (PV) during simulated digestion in vitro. The results showed that the IgE / IgG binding capacity of glycosylated PV was significantly reduced after digestion, reached the lowest after 2 hours of gastrointestinal digestion, then slightly increased after 3 hours. Peptides with a molecular weight ＜ 500 Da produced by pepsin digestion under the action of trypsin re-aggregate, and the digestion products all had new emission peaks with red shifting. The fluorescence intensity of the emission peaks also decreased first and then increased. The results indicated that the change of PV sensitization was closely related to the change of its structure. The combination of glycosylation modification and simulated human gastrointestinal tract digestion could effectively reduce the protein sensitization.

Abstract:Based on different hammering time, contrasted with the beating sample, the effects of hammering on the quality of beef gel were analyzed by measuring rheological properties, cooking loss rate, texture properties, salt soluble protein content, protein oxidation. In the process of dynamic frequency change, the hammering sample had a smaller phase angle (tanδ) than the beating sample; In the process of heating up, the hammering sample had higher storage modulus (G') than the beating sample; In the process of dynamic frequency change, the longer the hammering time was, the lower the G' and the bigger tanδ was, and rised rapidly at 55~75 ℃ during the heating process. G' gradually rised during the cooling process except for the sample of hammering 60 min. As the hammering time of the beef batter was prolonged, the salt soluble protein content increased, protein oxidation increased, the cooking loss rate of gel reduced first and then increased; the hardness and chewiness of gel reduced firstly and then increased, the springiness of gel increased firstly and then reduced, and the cohesiveness and recovery of gel were reduced. The correlation analysis showed that the degree of protein oxidation was negatively correlated with the gel hardness, but not with other indexes. The quality of gel will be improved as hammering time in 30 mins, and hammering for more than 30 mins would have an adverse effect on the gel properties. In a certain time, hammering process can increase the content of salt soluble protein, improve the rheological properties and texture properties of gel, this conclusion means the traditional hammering process has certain rationality and theoretical basis.

Abstract:In this study, 11 source PS enzyme genes were cloned and expressed in Escherichia coli BL21 (DE3), and the successful strain was constructed for enzymatic property study with simultaneous fermentation and transformation experiment on the fermentation tank. The results showed that the activity of PS derived from Brevibacillus brevis was the highest (1 562.3 U/mL), and the optimal temperature was 30 ℃, the optimal pH was 7.0, and the Kcat was 115.4 s^-1. The recombinant strain was fermented and transformed in a 5 L fermenter with D-pantothenic acid and β-alanine as substrates. After the reaction for 46 h, the yield of D-pantothenic acid reached 92.2 g/L, the conversion rate reached 93.7%, and the spatiotemporal yield was 48.5 g/(L·d).

Abstract:To study on the characteristics of condition of the fermenting grain entering the cellar and the original spirits of Lidu Texiang liquor in different seasons, the fermented temperature, moisture, acidity, starch and alcohol content of the fermenting grains were measured, and total acids and esters content, trace components, alcohol yield and sensory evaluation of original spirits were analyzed. The results showed that the fermented temperature presented significant differences in peak season, shoulder season and slack season. The cellar entry temperature is 16~19 ℃ in peak season, and the cellar entry temperature is 20~25 ℃ in the shoulder season and slack season. The fermentation speeds and overhead temperatures were different. The aciditiesof the fermenting grains in peak season, shoulder season and slack season were 1.1~1.4, 1.2~1.5 and 1.4~1.8 mmol/10 g, respectively. Besides, significant differences in acidity and total acids and esters content of wine were appeared in these seasons. Moisture entering the cellar during the peak season is 56%~58%, the shoulder season is 57%~59%, and the slack season is 58%~60%. Moreover, the starch in fermenting grains and the alcohol content in fermented grains in peak, shoulder and slack seasons revealed in descending order, and the obvious differences ofthe starch and alcohol content in grains andmicroconstituents in different seasons is found. It is noted that the quality of original spirits in peak season had advantage over shoulder season and slack season. Considering the fermentation characteristics of Texiang liquors in different seasons, in order to reduce the acidity of fermented grains and even improve the quality of new liquor, in shoulder season and slack season, the fermented temperature and the starch content in fermenting grains should be kept at a lower level and the moisture in fermenting grains at a higher level. This study will provide a theoretical basis for adjusting the brewing process of Texiang liquor in different seasons.

Abstract:The yeast was isolated from the strong flavor wine fermented grains by plate culture method, and the ester-producing yeast with good tolerance was screened, through morphological characteristics, physiological and biochemical tests, and molecular biology analysis of 26S rDNA in yeast. Finally, the effects of mixed fermentation of yeast and Saccharomyces cerevisiae on simulated liquor fermentation broth were studied. The results showed that in the tolerance test of simulated liquor brewing environment, the three strains of high-yield esterifying yeast all had certain acid resistance, and maintained good growth characteristics when the concentration of ethanol was 10%, but the growth characteristics were inhibited when the temperature was 40 ℃, and the yeast strain W5 had better tolerance than the other two strains of high-yield esterifying yeast, which was identified as torulaspora Delbrueckii); in the simulated liquor fermentation experiment of screening yeast and S. cerevisiae, the fermentation rate of S. cerevisiae was the fastest, with the fermentation for 6 days; the single fermentation time of T. delbrueckii W5 was 8 days; the mixed fermentation of T. delbrueckii and S. cerevisiae prolonged the fermentation cycle, and the fermentation time was 9 days. Under the control of the same conditions of cultivation and fermentation, the acidity of T. delbrueckii pure culture was higher than that of the other two culture methods, and its acidity ranged from 7.62 g/L to 7.72 g/L, indicating that T. delbrueckii had a high acid production capacity. However, the yield of T. derbrueckii W5 was lower than that of S. cerevisiae, and the range of its volatile acid was 0.32~0.48 g/L. In addition, the ethanol content in pure culture of S. cerevisiae was 13.18%~13.50%, which showed that S. cerevisiae had strong fermentation ability compared with T. delbrueckii. In view of the excellent ester-producing properties of T. delbrueckii, it was intended to provide a theoretical basis for its application in the production of the strong flavor wine. It was found that T. delbrueckii slightly prolonged the fermentation time, while the ability to produce acid and ethanol was greatly enhanced, and this could increase the yield and enrich the wine aroma.

Abstract:Lactobacillus in yak ghee at different altitudes in Tibet was screened through tolerance index of resistance to acid, hydrogen peroxide, and antioxidant indicators of scavenging capacity of DPPH free radicals, OH free radicals and superoxide anions. The results showed that 61 strains of bacteria were acquired from Tibet yak ghee, and 7 strains of them were well-tolerated to circumstances of low-acid and hydrogen peroxide. Among the 7 strains, C19 (Lactobacillus plantarum) had the highest scavenging capacity of DPPH free radicals and superoxide anions with the rate of 30.84% and 26.91% respectively. E1 (Lactobacillus rhamnosus) had the highest scavenging capacity of OH free radicals with the rate of 57.60%. No correspondence of scavenging capacity of DPPH free radicals, OH free radicals and superoxide anions was found, and altitude was not directly proportional to the antioxidant activity of Lactobacillus. C19 and E1 had potential in the research and development of natural antioxidants starter.

Abstract:The flavor characteristics of Lipu’s taro at different frying times (0.0, 1.0, 1.5, 2.0, 2.5, 3.0 min) were study based on sensory evaluation and electronic nose technique. Change values for each response sensor were observed by radar chart and Loading Analysis (LA), and data was analyzed and identified by Principal Component Analysis (PCA) and Linear Discrimination Analysis (LDA). The results showed that the flavor of taro by frying for 2 min was the best through sensory evaluation. Sensors S2, S7 and S9 played a major role in distinguishing the volatile flavors of Lipu taro with different frying time. It was found that the nitrogen oxides, sulfides, aromatics and organic sulfide had great contributions to distinguishing different kinds of fried Lipu taro.

Abstract:The fatty acid contents in muscle of eight species of needlefish were determined and compared for the development and utilization of the marine resource. In autumn and winter, 8 species of needlefish were collected from Zhanjiang sea area, including Hemiramphus far, Hemiramphus lutkei, Hyporhamp-hus dussumieri, Hyporhamphus limbatus, Hyporhamphus quoyi, Tylosurus acus, Strongylura anastomella and Strongylura strongylura. The moisture and crude lipid of muscle were determined by national standard method and the content of fatty acid in muscle was determined by capillary gas chromatography. The results showed that moisture of the muscle of needlefish was 66.7%~73.2% and crude lipid was 2.04%~2.78% dry weight. The contents of saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA) in muscle were 32.10%~42.97%, 11.99%~35.51%, 29.37%~43.92%, respectively. The content of n-3 fatty acids (21.19%~38.98%) and n-6 fatty acids (5.44%~18.24%) in 8 species of needlefish were high and have higher fatty acid nutritional value and medicinal value, among which the content of H. quoyi and T. acus EPA+DHA+DPA were 35.55% and 33.31%, respectively. The DPA contents in H. dussumieri and T. acus were high, reaching 8.43% and 7.31%, respectively.

Abstract:The flour properties of oats, barley, tartary buckwheat, sweet buckwheat and quinoa were analyzed, including the content of broken starch and amylose, particle size distribution, dough rheological properties and hydration properties. The results showed that the tartary buckwheat flour had the highest amylose content of 23.46%; the broken starch content of oats and quinoa was more than 20%; the barley meal had the highest dietary fiber content of 20.94%, and the barley meal had the largest particle size (D₅₀=41.12 μm). Highland barley and oats had higher water absorption rate, lower regeneration value, stronger dough toughness, shorter gelatinization time, and showed easier to cook; tartary buckwheat has lower water absorption rate, longer dough formation time, stronger dough binding force, shorter gelatinization, and starch had better gelatinization characteristics and thermal stability, with higher viscosity of the dough; sweet buckwheat had better gelatinization characteristics and thermal stability, while water absorption capacity was poor with high regenerative value. Quinoa had a low water absorption rate, a large degree of protein weakening, a long gelatinization time, and poor dough rheological properties, making it unsuitable for making noodles. Oat had the weakest capacities of water-holding and swelling, with the lowest water solubility, indicating that its products have the least cooking loss; tartary buckwheat has the best capacities of water-holding capacity and swelling, followed by highland barley and quinoa; when the temperature is 25 and 100 ℃, the water solubility of sweet buckwheat was the largest of the five kinds of miscellaneous grains, indicating that its cooking loss of noodle products was the highest.

Abstract:

Analyzed the nutritional value and antioxidant capacity of Shepherd’s purse seed. There were many kinds of nutrients in the seed of Shepherd’s purse. The content of crude fat ranked the first with 37.6 g/100 g, and among the crude fat, unsaturated fatty accounted for 87.28%, α-linolenic acid and linoleic accounted for 32.80% and 20.12%, respectively. The erucic acid took the only left 0.30%. The crude protein content was 18.7 g/100 g. The first limiting amino acid of crude protein was methionine, and its amino acid score was 64. Among the group of Vitamin E, contents of E-vitamin E was the highest at 14.0 mg/100 g. The contents of K、Ca、Mg were high among the minerals. The water extracts of Shepherd’s purse seeds had the strongest ability of scavenging DPPH·, which was about 1/20 of ascorbic acid. To H₂O₂, OH· and NO ,its capacity was about 1/40 to 1/20 of ascorbic acid.

Abstract:The hemicellulose hydrogel was used as the matrix to adsorb pyrrole monomer which undergoes in situ polymerization by chemical oxidation to form polypyrrole to produce the composite hydrogel with conductive properties. The chemical structure and microstructure were characterized and observed by using Fourier transform infrared spectroscopy, scanning electron microscope. The rheological properties under low shear frequency were measured by the rotary rheometer. The electrical properties were tested by four-probe tester and electrochemical workstation. It was found that the polypyrrole was successfully combined with hemicellulose hydrogel, and the resulting conductive hydrogel had a stable macroporous structure with strong water absorption capacity, with equilibrium swelling degree up to 420%. The prepared hydrogel shows high elasticity, exhibiting typical solid nature properties and certain pseudoplastic fluid properties. In addition, the composite hydrogels display good electrical properties. Its direct current conductivity reached 5.6×10^-3 S/cm, and the alternating current impedance had obvious frequency dependence.

Abstract:Sixteen elements (K, Na, Ca, P, Mg, Fe, Cu, Mn, Zn, Al, Cr, Ni, As, Cd, Hg and Pb) in canned food paste for infant were determined by ICP-OES/ ICP-MS after microwave digestion. Under the optimized conditions, the calibration curves for 16 elements were wide and correlation coefficients were greater than 0.999 7. Twenty samples were determined by the proposed method and the spiked recoveries were in the range of 88.5%~106.0%, the relative standard deviations were 1.46%~8.18% while the RSD ranges from 1.8% to 7.1% (n=8). The method provides the basis for scientific evaluation of the nutritional value and food safety risk of the supplement mud.

Abstract:SnO2/SiC hollow spheres, polyaniline nanowires, gold nanoparticles and other nano materials with good biocompatibility were modified on the electrode substrate and antibody probe to amplify the electrochemical signal, improve the detection sensitivity, and construct a direct competitive detection electrochemical sensor for aflatoxin B1. The results showed that the detection linear range of the sensor for aflatoxin B1 was 3.81 pg/mL~1.00 μg/mL, and the limit of detection was 1.13 pg/mL. The proposed sensor had good stability, reproducibility and specificity, and the detection recovery of the edible oils was between 84.6% to 107.6%, with the coefficient of variation between 5.42% to 10.49%, indicating that it can be used for the rapid screening of aflatoxin B1 in edible oils.

Abstract:In order to ensure the quality and safety of plant solid beverages, and increase the basis for export, a new experimental method was built for the determination of ten phytotoxins, including protostemonine, thujone, coumarin, berberine hydrochloride, safrole, santonin, aloin, asarone, isosafrole, pulegone in solid beverage by High Performance Liquid Chromatography(HPLC). The samples were extracted with acetonitrile, purified with QuEChERS, then them were separated by gradient elution in Wlech Xtimate C₈ column (4.6 mm×250 mm, 5 μm) and detected by PDA detector, with methanlo-ammonium acetate (10 mmol/L, pH 3.5). The results indicated good linear relationships in the range of 0.005~154.200 mg/L for the ten phytotoxins, with correlation coefficient greater than 0.997. The limits of detection (LODs, S/N=3) and quantification (LODs, S/N=10) of the method for the target compounds were in the range of 0.010~0.270 mg/kg and 0.032~0.830 mg/kg, respectively. The mean recoveries of negative samples at three spiked levels were between 78.46% and 100.77%, and the relative standard deviation (RSD, n=6) 1.10%~3.07%, the daily precision were 1.11%~2.73%. This method was suitable for the identification and quantification of ten phytotoxins in botanical solid beverage owing to its simplicity and accuracy.

Abstract:A quantitative model of vegetable oil adulterated with fried animal oil has been established based on near infrared reflectance (NIRS) and chemometrics. A spectroradiometer was used for collecting spectra collected in 10 000~4 000 cm^-1. The NIR spectra were collected from 100 samples. By using the TQ-Analyst, the best pretreatment method was obtained while choosing the total spectra area combined with PLS. The best pretreatment method is the first derivative combined with Norris derivative filter. The model is feasible, with the Corr. Coeff. of 0.992 0, RMSEP of 3.11, and the result of t-test is passable while the validation method is cross validation. In this paper, a feasible method is established to detect vegetable oil adulterated with fried animal oil.

Abstract:The social supervision mechanism in China's tourism food safety governance mainly includes three forms: consumer rights protection supervision, social organization supervision and industry self-discipline supervision. However, in the practical operation of social supervision mechanism, there are obvious problems, such as the lack of consumer rights protection ability, the lack of professional supervision ability of social organizations, and the lack of self-discipline management mechanism in the industry, which lead to the effect of social supervision mechanism is not obvious. Therefore, it is necessary to take targeted construction approaches such as publicity and education on consumers' rights protection of tourism food safety, establishment of a diversified social organization supervision system dominated by consumers' associations, and clarification of the legal obligations of tourism food safety self-discipline management of tourism food industry associations, so as to ensure the smooth operation of relevant social supervision mechanisms and obtain safe tourism for consumers Food provides reliable social supervision and security.

Abstract:According to the loads characteristics and working requirements of the rotor structure of the wheat peeler, the objective function, the design weight of the rotor, was solved under the constraints of input variables and state variables, here the structural parameters of the rotor were taken as the input variables, and the maximum deformation, natural frequency and maximum stress under the working load were taken as the state variables. The response surface method and the central composite design method were employed in the calculation. The numerical calculation experiment involves 150 sample points (groups), and three candidate points with composite state variable constraints were obtained. By this method, the maximum weight of the rotor can be reduced by 73.6 kg, the mass can be reduced by 35.16% compared with the original structure, and the maximum stress can be reduced by 12 MPa, meanwhile meeting the requirements of the structural strength, rigidity and dynamic stability of the whole machine. It shows that the lightweight design method can significantly reduce the quality of the peeling machine rotor on the premise of satisfying the performance of the machine.

Abstract:In view of the fact that the automatic meal-selling equipment in the market is not convenient enough and efficient, a double-layer unmanned vending storage cabinet equipment is designed. The equipment was composed of two parts: a food storage device and a lift-and-traverse meal-taking device. The food storage device is divided into two areas: the upper storage area is in the form of multi-layer side-by-side raceways, using the unified distribution mode of the central kitchen; the lower storage area is single-sleeve, by identifying and cooperating with the conveyor mechanism and the lifting storage / ejection mechanism It can carry out automatic storage and distribute food in the form of network orders. The lifting and traversing meal-taking device is used for taking out meals. In order to make the meal-taking device compact, the weight is reduced by 32.6% through optimization, which meet the expected requirements.

Abstract:Formula for calculating the area of the sieve openings by took soybeans as the object was derived, and sieving effects of cylinder sieves with different types of holes were also compared. It is concluded that the cylinder sieve with square sieve pores has the best screening effect on soybeans, which has been verified by simulation calculations. Besides, the paper chose the soybean sieve ratio and the impurity remove ratio to calculate the sieving effect. Orthogonal simulation calculations experiments were performed to obtain the influence order of different process parameters on the sieving effect of beans in cylinder sieves and the best process parameters: the tilt angle is 5°, the rotating speed is 16 r/min, the feeding speed is 14 t/h, and the sieve hole side length is 9 mm. Under the conditions, sieving effect increased by 3.89% from the original of 0.935.

Abstract:A new auto-cleaning equipment was designed and applied to the ZJ116A cigarette maker to reduce the frequency caused by “rolling plate jam” and solve the difficulty of cleaning up. The new device cleans the surface of the rolling drum with a brush driven by a motor, and cleans the surface of rolling plate with air controlled by IPC system. Both realized the automatic cleaning function. The“baisha (hard)” brand cigarette was tested on a ZJ116A cigarette maker, the results showed that: After modification, the frequency of rolling plate jam was reduced by 15 times/month, the manual cleaning times on rolling plate was reduced by 16 times/month, the manual cleaning times on rolling drum was reduced by 20 times/month, This method provides a technical support for promoting the efficiency of cigarette makers.

Abstract:An automated segmentation method of goat trunk with machine vision and machine learning was proposed. 396 images of goat trunk were acquired randomly in a goat slaughtering plant by using two industrial cameras. 24 sets of feature parameters were extracted by image processing. The characteristic parameters included the center (O), the centroid (Q) and the four vertex coordinates (ABCD) of the minimum circumscribed rectangle corresponding to the four parts of the body. 16 groups of characters were selected by significance test. The data was preprocessed with abnormal value detection and normalization methods. The hierarchical sampling method is used to divide the training and test set to 7∶3. The models such as Lasso, Ridge, SVR and GBDT in auto-sklearn are selected as individual learning cell. The automatic integrated learning algorithm is designed and constructed with Bayesian optimization method. When Lasso, SVR and GBDT are integrated with a weight of 0.30∶0.25∶0.45, the model predicts best. Finally, the MSE and R² scored 7.93 and 0.961, on test set. The experiment was carried out on a multi-joint robot. The error is 3.4 mm and the theoretical reached 413 units per hour,which increased by 37.9%. The results indicate that the method is effective and feasible.

Abstract:Compared the antibacterial activities of three phenolic acids (gallic acid, protocatechuic acid, and chlorogenic acid) against S. putrefaciens, and investigated the antibacterial effects of gallic acid on S. putrefaciens by means of scanning electron microscopy, flow cytometry, cell membrane integrity and permeability measurement. The results showed that gallic acid had the strongest antibacterial activity against S. putrefaciens among the three phenolic acids, and its minimal inhibitory concentration and minimal bactericidal concentration were 1.25 mg/mL and 2.5 mg/mL, respectively. After treatment with gallic acid at the minimum inhibitory concentration, the cell morphology of S. putrefaciens changed with obvious depression on the surface. The apoptotic rate increased significantly. The leakage of nucleic acid and protein increased, and the integrity of cell membrane was destroyed. The permeability of cell membrane increased, and a large amount of intracellular electrolytes leaked into the culture medium.

Abstract:To investigate the effect of vacuum freeze drying on phenolic content and in vitro antioxidant activity of four varieties of Chrysanthemum, including Dendranthemamorifolium(Ramat.) Tzvel., Florists Chrysanthemum, Bellis perennis L., and Chrysanthemum morifolium 'Hangju'. The results showed that the total phenolic content of Chrysanthemum was significantly increased after vacuum freeze drying. Among the four varieties, B. perennis L. displayed the highest percentage increase in total phenolics after vacuum-freeze drying (Increaseed by 2.525 times). The DPPH· scavenging capacity, ferric reducing antioxidant property and ORAC were significantly changed except ABTS+· scavenging capacity, which indicated that vacuum-freeze drying has great influence on the antioxidant activity of Chrysanthemum phenolics.

Abstract:The polysaccharides was extracted from O. lanpingens, and the molecular weight, monosaccharide composition and functional group characteristics were analyzed. Furthermore, the effect of O. lanpingensis polysaccharides on immunity was investigated. The results showed that OLP had a molecular weight of 3.2×10⁵ Da, and it was mainly composed of mannose, galactose and glucose with a molar ratio of 13.38:5.31:81.31. OLP might be an acid polysaccharide containing uronic acid and pyran ring. OLP could significantly increase the spleen index, reduce red pulp area congestion of spleen, improve the ability of clearing carbon particles, strengthen phagocytic function of mononuclear phagocytic system, promote the production of antibodies against sheep red blood cells and increase ConA-induced T lymphocyte proliferation. Moreover, OLP also increased gene expression levels of immune-related cytokines IL-2 and IL-10. These studies indicated that OLP could enhance the immunity of mice.

Abstract:The bee pollen of oilseed rape was used to investigate the effect of enzymatically breaking the wall for protein extraction, and the optimal conditions of the extraction were determined by single factor test and response surface analysis. After mixing 2.5 g of peak pollen and 50 mL of pH 5.96 aqueous solution, 0.4% volume fraction compound plant invertase (100 FBG/g) was added and then stirring and extracting at 42 ℃ for 6.5 h. Under the control of these optimal conditions, the protein pollen extracts were separated by Sephadex G-100 gel column to obtain a total of 4 components. However, only one of them was determined to contain protein with 66.77 g/100 g, with the contain of hydrophobic amino acid of 27.52 g/100 g. The amino acid composition analysis and infrared spectroscopy results showed that aromatic amino acids were found in bee pollen protein. Moreover, the circular dichroism chromatography results showed that the proteins in bee pollen were easily digested enzymatically for producing peptides.

Abstract:This paper used single factor and response surface analysis to optimize the fermentation process of peony seed meal soy sauce, and the antioxidant activity of peony seed meal soy sauce was studied. The result showed that the establishment of regression model reflects the relationship between the content of amino nitrogen and fermentation temperature, fermentation time and salinity of peony seed meal soy sauce. The optimum fermentation conditions of peony seed meal soy sauce were fermentation temperature of 45.5 ℃, fermentation time of 18 days, and salinity of 12%. Under the conditions, the content of amino nitrogen in peony seed meal soy sauce was 0.616 g/100 mL. According to the oxidation experiments in vitro, peony seed meal soy sauce under high temperature and high-pressure sterilization had better scavenging ability to DPPH free radicals, and the scavenging rate can reach 94.19%.

Abstract:The total flavonoid content, total polyphenols content and their antioxidant activities in eleven variety of hulless barley were determined and analyzed. Significant differences were found in active ingredients in hulless barley among different varieties and different habitats. The contents of total flavonoids and total polyphenols in Tibetan QB31, QB35 and Ni long hulless barley were significantly higher than those in eight kinds of Sichuan hulless barley, and the highest contents were 0.57 mg/g and 1.49 mg/g, respectively. Moreover, significant differences of total flavonoids content and total polyphenols content were detected in different varieties of hulless barley, and a strong positive correlation between total flavonoids content, total polyphenols content and antioxidant activity was found (P＜0.01). In addition, the clustering analysis of total flavonoids content and total polyphenols content could clearly distinguish Sichuan hulless barley from Tibet hulless barley, as well as dark hulless barley and light hulless barley.

Abstract:The effects of four extraction methods, which include hot water extraction, ultrasonic extraction, enzyme extraction and alkali extraction on the yield, structure and antioxidant activity of crude polysaccharide of lotus leaf were investigated. The results showed that the yields of polysaccharide were as follows: ultrasonic extraction＞ enzymatic extraction ＞hot water extraction＞alkali extraction. The polysaccharide extracted by four methods had four characteristic absorption peaks, including 3 388, 1 617, 1 400 and 1 137 cm^-1. The polysaccharides obtained by hot water extraction showed the best antioxidant capacity, but the extraction time was longer. In contrast, ultrasonic method is recommended with concerning about extraction time.

Abstract:In the present study, the Lapsang Souchong essential oil was prepared by using macroporous resin, during which the preparation process was optimized. Furthermore, the volatile aroma components and antioxidant activity of the product were analyzed. The results showed that the optimal process was using LX-8 macroporous resin as the adsorption resin, and the aromatic components were absorbed in a constant temperature shaker (25 ℃, 200 r/min) for 180 min. The ratio of resin wet weight and substrate was 1∶350 (g/mL). Subsequently, macroporous resin was desorbed by using 95% ethanol in a constant temperature shaker (25 ℃, 200 r/min) for 150 min. The ratio of resin wet weight to ethanol solution was 1∶5 (g/mL). Under the control of this condition, the highest concentration of Lapsang Souchong essential oil was obtained. The aromatic components were concentrated 35 times, with the recovery rate approximate 51%. Gas chromatography-mass spectrometry (GC-MS) analysis indicated that most of the characteristic aroma components of Lapsang Souchong were adsorbed by LX-8 macroporous resin. Furthermore, the product was found to possess profound antioxidant activity. Its DPPH and ABTS free radical scavenging activity are 4 and 3 μg/mL ascorbic acid equivalent, respectively.

Abstract:To investigate the antioxidant activity of different polar extracts from the stems of Ficus tikoua Bur. (FTB), the main chemical components of the highly active polar extracts were screened and identified. Petroleum ether, dichloromethane, ethyl acetate, n-butanol extract and water extract of the remaining upper layer were obtained by systematic solvent method. The antioxidant activities of different polar extracts were evaluated by the scavenging ability of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azino-bis-(3-ethylbenzothiazole-6-sulfonic acid) diammonium salt (ABTS) and total reducing ability (TRPA). HPLC-DAD-ESI/MSn-DPPH was used to quickly screen and identify the antioxidant characteristic components of higher polar parts from FTB stems. The results showed that the n-butanol extract had strong antioxidant activity (P＜0.05). With the concentration increasing, there is a significant dose-dependent effect. The IC₅₀ of n-butanol extract to DPPH and ABTS were (23.28±0.21) μg/mL and (76.30±1.13) μg/mL, respectively. Three compounds were identified to be 5-O-caffeoylquinic acid, 3-O-caffeoylquinic acid and 4-O-caffeoylquinic acid through comprehensive analysis of HPLC spectra, MS spectra, literature data and reference standards.

Abstract:The quality and physicochemical indexes of rice sour soup, made of glutinous rice, japonica rice and flour, were detected and the relative correlation with sensory scores were analyzed. Thereafter, the rice slurry was used to optimize the liquefaction and saccharification processes, as the reducing sugar and soluble solid content (TSS) were taken as evaluation indexes. The results showed that the highest sensory score was obtained as the raw material ratio was glutinous rice∶japonica∶flour 2∶1∶1. The sensory score was positively correlated with viscosity, total acid, reducing sugar, particle size, protein, TSS, b* (r=0.892, 0.862, 0.861, 0.861, 0.841, 0.822, respectively), while negatively with L* (r=-0.885). Moreover, a very complex relationship between the quality index of rice sour soup with different ratio of raw materials was found. The optimum conditions of rice slurry liquefaction were as follows: with the addition of liquefaction enzyme of 40 U/g, liquefied at 85 ℃ for 30 min, at pH 6. The optimum conditions for the saccharification of rice slurry were saccharified at 60 ℃ for 1.5 h, with the addition of 1 000 U/g saccharification enzyme at pH 5.

Abstract:To improve the content of umami substance in boiling water of Lentinus edodes, the single factor experiment and orthogonal experiment were carried out to optimize the enzymatic hydrolysis process of L. edodes boiling water with papain. The amino acid nitrogen content and equivalent umami concentration (EUC) were also evaluated after enzymatic hydrolysis by papain. Results showed that the optimum conditions for enzymatic hydrolysis to improve the content of amino acid nitrogen in boiling water of L. edodes by papain were as follows: pH value 6.0, enzymatic temperature 55 ℃, enzymatic amount 0.4% and enzymatic hydrolysis time 5 h. Under the control of these conditions, the content of amino acid nitrogen was 0.454 g/100 mL. Enzymatic hydrolysis could significantly increase the contents of glutamic acid and aspartic acid in boiling water of L. edodes as well as EUC.

Abstract:In this study, Lactobacillus casei 16 was used to ferment soymilk. The effects of different fermentation time, fermentation temperature and refrigeration time on pH value, total phenol content, free amino acid content, and physical properties of L. casei 16 fermented soymilk were further investigated. The orthogonal experiment was further adopted to optimize the fermentation conditions of L. casei 16 fermented soymilk, with total phenol content and free amino acid content as indicators. Moreover, the antioxidant capacity of fermented soymilk after optimization was also investigated. The optimized conditions were found that L. casei 16 was inoculated into soymilk with concentration of 2%, fermented at 37 ℃ for 24 h, and then refrigerated at 4 ℃ for 6 h after fermentation. Under the control of these conditions, the total phenol content was 13.94 mg/100 mL, and the that of free amino acids was 1.33 mg/mL, with the consistency of solution of 2 192.32 g·s. The total reducing power and hydroxyl radical scavenging ability were 0.31 and 79.43%, respectively, significantly higher than those of unfermented soymilk and unoptimized groups (P＜0.05).

Abstract:In order to promote the comprehensive utilization of tobacco waste, the process of fermentation of tobacco waste to prepare bacterial cellulose (baterial cellulose, BC) was studied. The methods of tobacco waste extracting were compared, and the conditions such as inoculum size, temperature, pH and fermentation time were optimized. The repeated fermentation verification was carried out and the structure and properties of BC prepared by fermentation with traditional HS medium were compared. The results showed that tobacco waste extract can directly produce BC as fermentation raw material without additional carbon source and nitrogen source. The optimal conditions for BC fermentation were inoculum size 6%, initial pH 5, temperature 30 ℃, fermentation 7 d. For different batches of tobacco waste, with the increase of sugar content in raw materials, BC production increased from 1.8 g/L to 2.5 g/L. In comparison, the water absorption performance of BC prepared by tobacco waste fermentation is comparable with the traditional HS medium fermented products, and their morphology and structures are not significantly different. Relying on biotechnology to produce BC by using tobacco waste fermentation provides a new way to expand the utilization value of tobacco resources.

Abstract:The fermentation mechanism of halophilic microorganisms during the fermentation of seafood condiments were reviewed, the influence of the metabolic pathway of halophilic bacteria on the characteristic flavor of traditional fermented condiments was introduced and its role in salt stress, flavor formation, and bioamine degradation was described. The mechanism of the influence of halophilic microorganisms on flavor was discussed in terms of amino acid metabolism, branched aldehyde formation and gene regulation influenced by microbiome.

Abstract:In this paper, the chemical and structures properties of starch commonly used in several noodle products were first introduced. And then the applications of starch, chemically modified starch, pregelatinized starch and resistant starch in noodle products were introduced respectively. Finally, the application prospect and challenges of starch and its derivatives in noodles are prospected in China.

Abstract:As a new type of heating method with high efficiency, energy saving and environmental protection, microwave heating is more and more widely used in industry. The Maillard reaction under microwave heating has a higher degree of early reaction. The composition of the middle products is different, and the volatile aromatic substances are more abundant. The physiological activities such as the antioxidant activity of the late products are significantly enhanced. Microwave heating has a significant impact on Maillard reaction products. This paper mainly introduces the influencing factors, products analysis methods, products types and application in food and research progress of Maillard reaction under microwave heating.

Abstract:It has been found that polysaccharides from kelp have many physiological activities such as lowering blood lipid, preventing radiation and anti-aging, and it isapplied to food, medicine and animal husbandry. The research progress of kelp polysaccharide on lowering blood lipids is summarized, in order to provide some references for the research of kelp polysaccharide on lowering lipids.

Abstract:The effects of different drying techniques on product quality and the relative advantages and industrialization obstacles of freeze-dried products were analyzed and compared in this study. The current practice in thin layer drying models of fruits and vegetables were discussed, and the characteristics of common models were also summarized. Furthermore, the effects of pre-freezing, such as pretreatment of freezing, control of freezing rate and regulation of ice nucleation on quality improvement and consumption reduction were clarified. This research focused on the positive effects of combined drying technology on shortening drying time, improving quality, saving energy and reducing consumption, and then the industrialization prospect of microwave-freezing drying technology was proposed. The development of freeze-drying technology of fruits and vegetables was prospected.