Abstract: In this study, the yields of oil and protein obtained from 4 extrusion methods and enzymatic hydrolysis of four enzymes were compared. Meanwhile, the relationship between protein molecular weight and oil yield during enzyme-assisted aqueous extraction process (EAEP) was also explored. By using alcalase 2.4L, oil was almost completely released after 3.6 h. The release of oil had an obvious correlation with molecular weight of the protein hydrolyzed from 70000 to 5000. After 3.5 h hydrolysis, 90% protein was hydrolyzed into peptide with molecular weight smaller than 5000. Oil cannot be released at the beginning of EAEP, due to the inhibition of protein with molecular weight larger than 70000.

Key words: extrusion, aqueous enzymatic extraction process, protein molecular weight, oil release