Effect of Ultrasonic Treatment on the Specific Milk-Clotting Activity of Goat Kid Rennet

Using 2-3-week kid abomasums as materials,influences of the ultrasound intensity,ultrasound treatment time,NaCl concentration and ratio of abomasums mucosa to extracting solution were investigated,and verification of the experiment was conducted.The results showed that these four factors very significantly affected specific milk-clotting activity of goat kid rennet.The interactions between ultrasound intensity and ratio of abomasums mucosa to extracting solution,and extraction time and ratio of abomasums mucosa to extracting solution also had significant effect on the specific milk-clotting activity.The optimal extraction condition obtained was: ultrasound intensity,38 W/cm~2;extraction time,25 min;NaCl concentration,14%;ratio of abomasums mucosa to extracting solution,1∶30.Under the condition the maximum predicted value could reach 267.320 SU/mg, which was indifferent from the experimental value.