Extraction of cottonseed protein

The extracting conditions for cottonseed protein with alkali method and salt method were investigated by single factor and orthogonal experiment.The optimum conditions for alkali extraction were as follows: pH 10,temperature 40℃,ratio of water to stuff 10 ∶1,extraction time 60 min,and the extraction rate of protein was 75.5% under the optimum conditions.The optimum conditions for salt extraction were as follows: sodium chloride mass concentration 100 g/L,temperature 40℃,ratio of water to stuff 15 ∶1,time 80 min,and the extraction rate of protein was 72.0% under the optimum conditions.The extraction rates of protein with the two methods were similar.Compared with alkali extraction,the protein product extracted by the salt extraction had higher purity,lighter color and lower free gossypol content.