To study the action of Alcalase and Protamex on the proteins of soybean, the influence of the temperature, pH, substrate concentration, enzyme concentration and hydrolysis time on the soluble protein recovery of the soy-proteins was evaluated. The soy protein was hydrolyzed by two different enzymes. | Journal of Science and Technology 55 (2) (2017) 137-149 DOI: RELEASE BIOACTIVE PEPTIDES FROM ENZYMATIC HYDROLYSATED SOYBEAN BY ALCALASE AND PROTAMEX USING RESPONSE SURFACE METHODOLOGY Nguyen Thi Quynh Hoa*, Dong Thi Anh Dao* HCMC-VNU University of Technology, 268 Ly Thuong Kiet Street, Ward 14, District 10, Ho Chi Minh city, Viet Nam * Email: nguyenthiquynhhoa2016@; dtanhdao@ Received: 19 February 2016; Accepted for publication: 21 January 2017 ABSTRACT Bioactive peptides have been defined as specific protein fragments that have a positive impact on body functions and conditions and may ultimately influence health. The objective of this paper is to study the enzymatic hydrolysis process of soy protein to produce bioactive peptides. To study the action of Alcalase and Protamex on the proteins of soybean, the influence of the temperature, pH, substrate concentration, enzyme concentration and hydrolysis time on the soluble protein recovery of the soy-proteins was evaluated. The soy protein was hydrolyzed by two different enzymes. Response surface methodology (RSM) was applied to optimize the hydrolysis conditions using Alcalase and Protamex. The result showed Alcalase L has the stronger hydrolysis capacity. The protein recovery was also higher with Alcalase, the soluble protein recovery by Alcalase was ± %, by Protamex was ± %. The highest soluble protein recovery for soy protein was obtained with a [E/S] of % (w/w) and % (w/w) for Alcalase and Protamex, respectively. For soy protein the conditions to get the highest soluble protein recovery were: 55 oC, pH 7, the ratio of soybean: water, : and reaction time of 180 mins, for both enzymes. The dried hydrolysate was low to medium molecular weight bioactive peptides (predominantly < kDa for Alcalase and < 20 kDa for Protamex). The results of amino acid analysis showed that the composition of amino acid of soy protein and .