| The defatted coconut powder was fractionated and extracted by modified Osboren method to obtain albumin, globulin, alcohol soluble protein and gluten, and their amino acid compositions and SDS-PAGE electrophoresis were analyzed. Based on single factor experiment, the preparation conditions of the four kinds of coconut proteins were optimized by orthogonal experiment. The results showed that the optimal preparation conditions of the four kinds of coconut proteins were obtained as follows: ①ratio of liquid to material 10∶?1, extraction time 4 h and extraction temperature 50?℃ for albumin, reaching 49.05% of extraction rate and 57.1% of purity;②ratio of liquid to material 10∶?1, extraction time 4 h and extraction temperature 50?℃ for globulin, reaching 46.65% of extraction rate and 70.8% of purity;③ratio of liquid to material 10∶?1, extraction time 5 h, extraction temperature 55?℃ and volume fraction of ethanol 75% for alcohol soluble protein, reaching 18.01% of extraction rate and 32.7% of purity;④ ratio of liquid to material 10∶?1, extraction time 4 h, extraction temperature 50?℃ and alkali-soluble pH 10.0 for gluten, reaching 26.78% of extraction rate and 70.4% of purity. The contents of glutamic acid, arginine and aspartic acid in albumin, globulin and gluten were significantly higher than that of other amino acids. Electrophoretic analysis showed that there were two bands with relatively large molecular weights in albumin, and the other three coconut proteins had relatively small molecular weights. Overall, coconut protein was a relatively high quality protein. |
