酶解改性对葵花分离蛋白功能性质的影响

Effects of Enzymatic Hydrolysis on the Functional Properties of Sunflower Protein Isolate

葵花蛋白的溶解性差限制其在食品工业中的应用,以葵花籽为原料制备了葵花分离蛋白（SPI）,并利用碱性蛋白酶对蛋白进行酶解,得到了3种不同水解度的酶解产物,探讨水解度（DH）对蛋白质功能性质的影响。结果表明,不同水解度酶解产物的氨基酸组成比较接近,必需氨基酸含量十分丰富;酶解产物在pH为2~11的范围内溶解度均达到90%以上;产物的表面疏水性有不同程度的降低;相对于SPI,酶解产物（DH 10%）的乳化性和起泡性分别提高了1.2和3.6倍,但乳化稳定性和泡沫稳定性分别降低了59.2%和32.4%。

The worse solubility of sunflower protein limits its application in food industry. Sunflower protein isolates （SPI） were prepared from sunflower seeds and hydrolyzed by using alcalase. Protein hydrolysates of three different degrees of hydrolysis were obtained. The effect of DH on the functional properties was discussed. Results revealed that hydrolysates with different DH had desirable essential amino acid profiles and showed the similar amino acid compositions. The solubility of the hyrolysates was above 90% in the range ofpH 2-11; The surface hydrophobicity of the hydrolysates reduced to a certain extent; Compared with native SPI, the emulsifying capacity and foaming capacity of hydrolysates with DH of 10% was increased by 2.3 and 1.6 folds, respectively. However, the emulsifying stability and foaming stability were decreased by 59.2% and 32.4%, respectively.