Study On The Preparation Of Antioxidative Peptides From Corn Gluten Meal And Microcapsulation

ObjectiveAcid pulp is formed by sweet potato(or mung bean)starch milk natural fermentation,it is a kind of liquid taste acid and its color is white.In the process of sweet potato production add acid pulp,the starch particles will have aggregation and quickly form clumps,increase the speed of separation of starch and other impurities.Acid pulp used in the production of starch is equivalent to the effect of a kind of microbial flocculant,it was widely applied in real life.This study uses the old Beijing solidify acid fermented sweet potato pulp,to determine the technology of natural fermentation of sweet potato acid pulp,separate the advantage bacteria in the fermented acid pulp.Using response surface analysis theimpact of 8 kinds of medium composition and culture temperature,pH,training time and the impact of the inoculation amount of bacteria,determine the optimal culture conditions.Using single factor experiment and orthogonal experiment analysis of different inoculation quantity,metal ion effects on sweet potato starch flocculation conditions.Analysis the effect of flocculation with different centrifugal revolutions and protective agent for producing.Use ultrasonic extraction method and guanidine hydrochloride extraction method to extract the pair binding protein of lactobacillus casei,determine the molecular mass of starch.This experiment improve the yield and quality of starch products,provide the theoretical basis and technical support in the future study.Methods1.The acid fermented sweet potato pulp,measured under the condition of different time(36 h,12 h,24 h,48 h,60 h,72 h,84 h,96 h)acid slurry’s pH and flocculating rate.By the analysis of metagenomic technology to analysis the advantage bacteria,analysis the DNA quality and Alpha diversity and its abundance.2.Study the effect of different nutrients on flocculating activity.Choose culture medium including carbon source,nitrogen source,incubation time,incubation temperature,initial pH value and the inoculation quantity,through the response surface analysis,with flocculating rate as the evaluation index,confirm the optimum culture conditions.3.By single factor experiment and orthogonal experiment,with different metal ions,the inoculation quantity,initial pH value of factors,analysis the effect on strain flocculation,determine the optimum flocculation conditions of lactobacillus casei.4.Centrifuge the acid pulp,drying in vacuum freeze,preparation of acid pulp producing,analysis the condition of 2000 r/min,3000 r/min,4000 r/min and5000 r/min the acid pulp state,consider different processing conditions includes10% glycerol,10% concentration of sucrose,10% concentration degrease emulsion and blank tube as comparison,determine the influence of different protective agent get of rate.With different methods ro extract bacteria function protein,including the method of ultrasonic broken,guanidine hydrochloride extraction,for electrophoresis operation,analysis the molecular weight of flocculating substance,and the effect of different protein on the flocculation.Results1.In different fermentation time,the number of pH showed a trend of gradually decline,flocculating rate showed a trend of decline after rising first,when 12 h pH number is 4.18,fell to 3.35 in the fourth day.Acid pulp highestflocculating rate in 70 h,the high flocculating rate is 69.23% in the pH value of3.62.Strains in acid pulp is composed of short rod-shaped bacterium chain.Sweet potato starch under natural condition were distributed evenly,add the sweet potato starch the acid pulp together and form a group under the microscope.In the volumetric flask of visual we can see large snowflake precipitation,it is fast.Natural fermentation of sweet potato acid pulp’s V4 area have total of118465 effective sequences,93295 series,the main bacteria in natural fermented sweet potato pulp acid is lactobacillus casei,the richness index of supernatant(Chao/Ace)at the sample of 598.94/463.62,the richness index of the sample is 583.85/421.20.2.By PB experiment design and response surface analysis to determine the three significant factors for amount of glucose addition,K2HPO4 content and temperature.Finally determine the optimal culture conditions of pair of lactobacillus casei is: the optimum adding amount of glucose is 26 g/L,K2HPO4 for 8 g/L,culture temperature for 31℃,microbial flocculation rate was 74.39%.3.Determine the biggest influence factor for flocculating rate is the inoculation quantity,followed by the pH and the metal ion,in the quantity of 15%,pH value of 5.5,1ml of Na+1,the flocculation rate as high as 76.03%,but consider the cost of the metal ions we identified it as the unimportant factor.4.Natural fermentation of sweet potato acid slurry flocculating rate was about 76%,to decline after lyophilization,add the protective agent in producing,sucrose as protectant producing flocculating rate is highest,at 59.27%,followed by 52.14% by skim milk,glycerol as protectant producing flocculating rate was45.25%.With the increase of time,producing the flocculating rate declined,but gentle.5.Starch combined protein was extracted with two methods and for SDS-PAGE,it can be seen that the ultrasonic extraction method to extractprotein was between 35 to 48 k Da,guanidine hydrochloride method to extract the bacteria was between 30-50 k Da,there are more than sixty kinds of proteins by mass spectrometry analysis of bacteria,including eight kinds of protein has a significant effect on flocculation,the most significant effect is cell wall hydrolases.ConclusionsThe acid fermentation of sweet potato pulp’s effect is better,to determine the flocculation effect of strains is pair of lactobacillus casei.PB experiment design and response surface analysis is used to determine the strain optimal culture conditions for: the best addition amount of glucose to 26g/L,the best level of K2HPO4 is 8g/L,the best temperature for 31℃,the microorganism flocculating rate is 74.39%.Through single factor experiment and orthogonal experiment to determine the optimum flocculation conditions as follows: 15%inoculated quantity,pH value of 5.5,the flocculating rate of 76.03%.Of producing flocculation effect,sucrose as the protective effect is best.After four months on the vitality of around 50%.Finally extract bacteria between 30-50 k Da protein,there are eight kinds of protein has significant effect on flocculation,the most significant effect of cell wall hydrolases.