Study On Manufacturing Technique Of Antinutrition Factors-free Soybean Meal Feed Based On Steam Explosion

Soybean meal is particulate matters made by the soybean after peeling,expelling,puffing,wet meal evaporation,particle crushing and other technological preparations,which rich in protein and reasonable amino acid composition ratio.In China,the consumption of soybean meal is huge,only in 2016 it reached 65.26 million tons,of which 80%soybean meal used for poultry and livestock.Some substances of soybean meal which called anti-nutritional factors can cause the edible animal intestinal discomfort,diarrhea,allergies and so on.The major components are the soybean glycinin,soybean β-conglycinin and trypsin inhibitor.In order to remove the anti-nutritional factors and improve the nutrient absorption rate of soybean meal,we used solid state enzymatic hydrolysis,steam explosion and the united technology of steam explosion and solid state enzymatic hydrolysis in this paper.1.We used the response surface to optimize the conditions of solid state enzymatic hydrolysis of soybean meal with reference to the hydrolysis degree.The ultimate enzymatic hydrolysis conditions were that adding protease 5.5%,keeping 40%water content and 38℃ for 48 h.After enzymatic hydrolysis,the hydrolysis degree of soybean meal up to 8.53%.And the content of glycinin was 13.50 mg/g DM,the removal rate reached 92.6%;the content of β-conglycinin was 10.64 mg/g DM,the removal rate reached 93.4%;the content of trypsin inhibitior was 0.078 mg/g DM,the removal rate reached 99.0%.The acid soluble protein content of soybean meal treated by hydrolysis was 0.082 g/g DM which increased by 4.89 times compared to CK.And the protein solubility in KOH solution also increased to a certain extent.2.The contents of anti-nutritional factors,acid soluble protein,protein solubility in KOH solution were used to estimate the treatment effects of the soybean meal treated by steam explosion.After steam explosion treatment,the removal rates of anti-nutritional factors in soybean meal(soybean glycinin,β-conglycinin,trypsin inhibitor)were respectively 68.3-96.9%,72.3-98.0%,59.7-90.1%.The in vitro N digestibility was 43.2-58.9%.The content of acid soluble protein had no significant changes,but the protein solubility of KOH decreased significantly.3.Based on the conditions of solid state enzymatic hydrolysis,we determined to adjust the pH value by phosphate buffer and adding sodium sulfite to promote the enzymatic action.We optimized the content of phosphate type and the additives amount of sodium sulfite.The final choice was that used the soybean meal treated by steam explosion of 0.5 Mpa stabilize pressure for 60s for enzymatic hydrolysis experiment.The conditions of solid state enzymatic hydrolysis was adding protease 5.5%and 0.01%sodium sulfite,then adding 0.05 mol/L sodium phosphate-potassium buffer(pH 6.3)to 40%moisture content,final setting in 38℃ for 48h.The content of acid soluble protein of the soybean meal treated by the above condition was 0.165 g/g DM,in vitro dry matter digestibility was 48.86%,in vitro N digestibility was 72.71%,the removal rates of anti-nutritional factors(soybean glycinin,β-conglycinin,trypsin inhibitor)were 98.9%,97.7%,98.8%.After the scale-up experiment by using 20L steam explosion machine,the content of acid soluble protein of soybean meal treated by ultimate disposal reached 0.197 g/g DM.The removal effect of three anti-nutritional factor was still obvious.Only treated by steam explosion,the removal rates of soybean glycinin,β-conglycinin and trypsin inhibitor were 89.7%,86.9%,86.1%.After enzyme hydrolysis,three kinds of anti nutritional factors,the removal rate respectively reached 97.4%,97.9%,99.9%.4.We use the soybean meal treated by three treatments of steam explosion(SESB),enzyme treatment united steam explosion(SEESB)and commercial fermented soybean meal(FSB)as raw material,replaced 15%,30%and 45%the content of soybean meal in soybean-corn diet.After balancing nutrition,we fed chickens for 3 weeks.The feed efficiency was determined by growth performance in 3th week.The content of three anti-nutrition factors and volatile basic nitrogen were related to the addition of replaced soybean meal.Feed results showed that SESB was better than SEESB.The FSB was worst which showed that SESB would supersede in the future.