Study On Strain Screening?Combinatorial Optimization And Production Engineering Of Solid-state Fermented Cottonseed Meal

Cottonseed meal is a kind of high-quality protein raw materials,but use is limited in the food and feed,the main reason is that have a higher concentration of toxic free gossypol and palatability is poorer,by microbial fermentation can effectively will cottonseed meal degradation of macromolecular substances fermentation for easy by gastrointestinal digestion,absorption and utilization of small molecules,balanced amino acids,reduce the pH,degradation of free gossypol,rapidly improve the product flavor and the use of conversion rate,improving palatability,thus promote the cottonseed meal value.This study first by using the method of combination of liquid and solid state fermentation,select the bacillus,lactic acid bacteria and yeast each one individual plant as the distribution of species,and the above-mentioned species distribution;Then,the optimization of the solid-state fermentation process of compound strains,finally has carried on the medium scale production test of fermented cottonseed meal.This study will be divided into three parts.1?Screening and complex of solid state fermentation strains of cottonseed mealThis experiment by using the method of combination of liquid and solid state fermentation,with the corresponding index of bacillus,lactic acid bacteria and yeast respectively to filter,then sieved strains for orthogonal test to determine the optimal proportion,finally according to the optimal ratio of the mixed strains,test in lab for cottonseed meal fermentation,detection of its associated indicators.Test results:1?single strain screening budding bacillus KC-1?lactic acid bacteria SS-2?yeast JS-1 as the distribution of strain.2?the best ratio of the mixed strains for:KC-1:SS-2:JS-1 =2:1:2.3?according to the optimal ratio of the mixed strains fermentation cottonseed meal after the main indicators are:free gossypol content of 213.36 mg/kg,the crude protein content 48.21%,acid soluble protein content 13.40%,the small peptide content 5.60%,organic acid content 1.68%,pH 4.84,the total number of living bacterium 8.20×108CFU/g,suitable fermentation flavor pleasant.This test for the cottonseed meal mixed bacteria starter cultures related product development has laid a good foundation.2?The Optimization for compound strains solid-state fermentation processThis experiment of fermented cottonseed meal solid-state fermentation was optimized by using response surface analysis technology,from the test results showed that when the quantity of 5%,fermentation temperature was 27.8?,fermentation time was 68.4 h,while solid-liquid ratio 1:0.82,the cottonseed meal:corn = 9.5:0.5,free gossypol degradation rate was 72.98%,consistent with the theoretical value.3?Cottonseed meal solid-state fermentation pilot the indicators and product testingMedium scale production according to KC-1:SS-2:JS-1 = 2:1:2 strain distribution ratio,quantity of 5%,fermentation temperature 28?,fermentation time 68.5 h,solid-liquid ratio 1:0.82,cottonseed meal:corn = 9.5:0.5 the fermentation conditions of solid-state fermentation of cottonseed meal,cottonseed meal after fermentation is before fermentation,free gossypol content by 61.14%,crude protein content increased by 1.76%,acid soluble protein content and small peptides content increased by 7.08%and 2.56%respectively,lower pH below 5.0,organic acids and amino acids content increased by 1.17%and 2.15%,effective number of living bacterium raised 1000 times,mycotoxin a downward trend,cottonseed meal after fermentation flavor have improved significantly.Medium scale production index is more ideal,laid a good foundation for large-scale production.