核桃蛋白组分的营养价值、功能特性及抗氧化性研究

Nutritional value,functional characteristics and antioxidant activities of fractions in walnut protein

以"清香"核桃为原料,经液压榨油机冷榨取油后得到核桃饼,将其粉碎,再用石油醚对核桃饼进行脱脂处理得到脱脂核桃粕,从中提取清蛋白、球蛋白、醇溶蛋白、谷蛋白-1、谷蛋白-2 5种蛋白质,并测定5种蛋白质的营养价值、功能特性及抗氧化性。结果表明:5种蛋白质氨基酸组成中,谷氨酸含量最高,精氨酸次之,5种蛋白质均具有良好的乳化性、乳化稳定性;谷蛋白-1必需氨基酸含量最高,占37. 14%,谷蛋白-2的乳化性、起泡性和泡沫稳定性最佳,分别为278. 66 m2/g、50. 03%、60. 01%;球蛋白乳化稳定性最高,为75. 27%;清蛋白对DPPH自由基清除能力最高,清除率为97. 15%。

'Qingxiang' walnut was used as material. After the oil was extracted by hydraulic press,the walnut cake was obtained. The walnut oil was defatted with petroleum ether to obtain the defatted walnut meal,and the albumin,globulin,alcohol soluble protein,glutelin-1 and gluten-2 were extracted. The nutritional value,functional characteristics and antioxidant activities of the five proteins were determined.The results showed that the glutamate content in the five protein amino acid components was the highest,followed by arginine,and the five proteins all had good emulsifying ability and emulsion stability. The essential amino acid content in glutelin-1 was the highest,accounting for 37. 14%. The emulsifying ability,foamability and foam stability of gluten-2 were the best,which were 278. 66 m2/g,50. 03% and60. 01%,respectively. The globulin had the highest emulsion stability (75. 27%). Albumin had the highest DPPH· scavenging ability,which was 97. 15%.