Abstract: In this study, the effects of pH, temperature, material-to-liquid ratio, and extraction time on the extraction rate of   alkali-soluble protein (ASP) from kidney beans grown in Qiangjiang region were explored by one-factor-at-a-time design. The optimal process conditions for ASP extraction were determined by response surface methodology as pH 8.93, material-to-liquid ratio of 1:10.67, extraction time of 22 min, and extraction temperature of 48 ℃. The protein isolate obtained under these conditions was analyzed for functional properties such as water-holding capacity, oil-absorbing capacity, foaming properties and emulsifying properties.

Key words: kidney beans grown in Qiangjiang region, protein extraction, protein isolate, functional properties