Optimization of protein extraction from defatted bitter melon seed using response surface methodology

The optimum extracting conditions of protein from bitter melon seeds by the salt solvent method were studied.The effects of concentration of NaCl, pH and extraction time on the yield of protein were studied based on the extraction rate.According to the single factor experiments, the optimum extract process for bitter melon seed protein was determined through Box-Benhnken central composite design and response surface methodology.The results showed that the optimized extract process for bitter gourd seed protein was that the material/liquid ratio was 1:6 and the temperature was at 4℃, the concentration of NaCl was 1.3mol/L and pH8.8, at a extract time of 3.6h, the extraction rate of bitter gourd seed protein was 23.80%, 3.24 times higher than that before the optimization.In addition, a quadratic equation model for protein extraction was set up and it played an important role in predicting the extraction of protein.Furthermore, the protein content of bitter melon seeds was 32.13% determined by Kjeldahl method.