Abstract: Degreasing of silkworm pupa is a vital step prior to others in the refining process, throughout which it is necessary to maintain the protein activity of silkworm pupa.Technology of ultrasound-assisted mesothermal degreasing silkworm pupa was investigated, and response surface methodology was used to optimize the operating parameters and the corresponding prediction models were established.The optimal degreasing conditions were acquired by single-factor experiments and response surface methodology, and listed as follows：petroleum ether：acetone(3∶7)as solvent, liquid-solid ratio 11 mL/g, ultrasound power 125 W, ultrasonic treating time 27 min, and temperature 40℃.The degreasing ratio of silkworm pupa reached(96.8 ± 0.8)％ under these conditions, and the results showed that the degreasing ratio of silkworm pupa was affected in decreasing order by liquid-solid ratio, ultrasonic treating time and ultrasound power.The effects of solvent types and liquid-solid ratio were the decisive factors resulting in the variation of degreasing efficiency of silkworm pupa.Overall, the ultrasound-assisted degreasing process owns the advantages of low temperature, short time, no damage to the activity of product, and high degreasing ratio.

Key words: silkworm pupa, ultrasound-assisted, mesothermal degreasing, response surface methodology