Effects of Extrusion and Fermentation Treatment Methods on Nutritional Value of Soybean Meal

To study the effect of different treatment methods on the nutritional value and the removing of anti nutritional factor in soybean meal,extrusion method and fermentation method were selected to treat soybean meal.The general nutrition composition,amino acid content,anti nutritional factors and mycotoxin content,volatile basic nitrogen content and microbial populations of soybean meal treated by extrusion or by fermentation were analyzed.The results showed that the extruded soybean meal had a reducing trend of nutrient content compared with the soybean meal without treatment.The protein solubility,trypsin inhibitor,lectin and urease activity were about 15.27%,37.95%,93.98%and 44.0%lower,respectively,than soybean meal without treatment.The fermented soybean meal had a increasing trend of nutrient content compared with the soybean meal without treatment.The crude protein,lysine,total amino acids and small peptide were about 7.61%,17.75%,7.24%and 295.69% higher,and the solubility of protein and crude fat were about 23.18% and 42.86% lower,respectively,than soybean meal without treatment.Moreover,trypsin inhibitor and lectin were not detected,and the urease activity was only 0.01 U/g in fermented soybean meal.The aflatoxin B1concentration in fermented soybean meal was 46.15%lower than that in the soybean meal without treatment.The fermented soybean meal was also rich in bacteria.In conclusion,fermentation method is a more ideal method for the removing of anti nutritional factor in soybean meal than extrusion method.