| High temperature desolventized soybean meal was treated by extrusion method. The effects of extrusion temperature on quality of extruded soybean meal and protein structure were analyzed and discussed. The results showed that with the increase of extrusion temperature, nitrogen soluble index and protein dispersibility index increased at first and then decreased, while trypsin inhibitory activity decreased constantly. When the extrusion temperature was 60?℃, the secondary structure of extruded soybean meal protein had a slight change and protein was denatured partly. At the same time, nitrogen soluble index and protein dispersibility index were the largest, which indicated that appropriate denaturation of protein was beneficial to improve the quality of soybean meal. In addition, fluorescence intensity of extruded soybean meal protein gradually increased and then slightly decreased with the increase of extrusion temperature. When the extrusion temperature was 60?℃, the polarity of tryptophan residues microenvironment increased and the tertiary structure of protein was less compact. |
