The optimization of conditions for the production of acid-hydrolysed winged bean and soybean proteins with reduction of 3-monochloropropane-1,2-diol (3-MCPD)

Response Surface Methodology (RSM) was used to establish the optimum time and temperature for production of acid-hydrolysed winged bean protein (aHWBP) and acid-hydrolysed soybean protein (aHSBP). Seven hours of hydrolysis at 125 degreesC was the optimum condition for producing aHWBP, whereas it was 5 h of hydrolysis at 125 degreesC for production of aHSBP. Although aHWBP and aHSBP produced using these conditions had favourable sensory qualities, they were found to have up to 25 mg kg(-1) of 3-monochloropropane-1,2-diol (3-MCPD). This exceeds the maximum level permissible in Commission Regulation (EC) No 466/2001. However, additional alkaline thermal treatment at pH 8.5 for 2 h at 100 degreesC effectively reduced the 3-MCPD contents of aHWBP and aHSBP to undetectable levels. aHWBP has a distinctive flavour, which is different from that of aHSBP. The former has higher mean scores for meaty and vegetable attributes but lower mean scores for soy, umami and beany attributes than the latter.