A study on leaf protein extraction and purification of white clover

The leaf protein (LPC) of white clover （Trifolium repens） were extracted and purified by single factor experiment. Heat time, temperature, pH value, the sort of acid and the ration of fresh leaf to water as extracting factors were studied in extracting leaf protein. Methanol, ethanol, acetone, carbon tetrachloride, water as extracting solutions were studied in purifying leaf protein. The results showed that the optimum time, temperature, pH value, acids and the ration of fresh leaf to water were 9 minutes, 90 ℃, 4.0, nitric acid, 1∶2, respectively. The result of orthogonal experiment showed that the sequence of the factors in affecting extraction ratio of the LPC was pH value, temperature, heat time and the ratio of fresh leaf to water. The optimum combination condition was pH value 4.0, temperature 90 ℃, heat time 9 min and the fresh leaf to water 1∶2. The result of the purification method showed that the sequence of the purifiers in affecting protein purification was methanol, ethanol, acetone, carbon tetrachloride, water; and there were not significant differences (P0.05) among the factors.