Abstract: The improvement of the traditional gelatin extraction process can help to improve the production efficiency. We used animal bones to extract gelatin by ultrasonic technique. Based on the single factor experiments, the influence of the hydrochloric acid concentration, ultrasonic power, pickling time, ratio of liquid to materials for removing minerals was determined. The bone was desalted with HCl on the best conditions as follows: HCl concentration, 3%; ultrasonic power, 1000 W; pickling time 3 d, the weight of bone: the weight of HCl 1∶ 10. The best condition for the gelatin extraction yield was determined as follows: alkali soaking time, 6 d; ultrasonic power, 1000 W; water extraction pH 5; the weight of bone∶ the weight of water, 3∶ 10. The gelatin extraction yield was 14.52% under the best condition. The distribution of gelatin molecules was measured by SDS-PAGE, while the relative content mass was measured by BCA method. The SDS-PAGE results showed that distribution of gelatin molecules was within a range from 20.0 to 94.4 ku. The protein extraction rate was higher at 60℃.

Key words: animal bone, gelatin, ultrasonic wave