Extraction of peanut protein isolate from defatted peanut powder

Peanut protein isolate was prepared from defatted peanut powder through alkali extraction and acid precipitation.The extraction process was optimized by single factor and orthogonal experiments,and the optimal conditions were determined as follows:extraction temperature 60℃,ratio of material to liquid 1∶9,pH 9.0 and extraction time 90 min,acid precipitation pH 4.5.Under the optimal conditions the extraction rate of protein was 42.5% and the purity of the finished product was 95.65%.The protein isolate obtained had good functional properties.