热榨和冷榨核桃饼粕中蛋白质提取及其性质研究

摘要

To optimize the extraction conditions of protein from the degreased walnut dregs, and make rational use of protein of cold pressed walnut dregs and traditional pressed walnut dregs, the single factor and the orthogonal experiment were used in the present study, also the characteristics of proteins extracted from traditional pressed walnut dregs and cold pressed walnut dregs were also investigated. The results show that the optimum extraction conditions were: SLR 1:8, temperature 60℃, pH 9.0, time 60 min and the extraction yield was 78.13 % under these conditions. The functional properties results of proteins extracted from cold pressed walnut dregs and traditional pressed walnut dregs revealed that both of them were highly soluble in the range of pH, water absorbency, oil absorbency were up to (5.60±0.30) g/g for CPWP, (4.27±0.16) g/g for TPWP and (5.70±0.28) g/g for CPWP, (6.59±0.21) g/g for TPWP, respectively. In addition, both of CPWP and TPWP were good digestive properties in vitro without significant difference.%为优化核桃脱脂饼粕中蛋白质的提取工艺,并合理利用热榨和冷榨脱脂方式所得核桃饼粕的蛋白质,通过单因素试验和正交试验对冷榨脱脂核桃饼粕中蛋白质的提取工艺进行了优化,并对两种脱脂饼粕蛋白质的加工特性进行了比较研究.结果表明冷榨脱脂核桃饼蛋白质的最佳提取条件为:料液比1:8,pH值9.0,提取温度60℃,提取时间60 min.在此条件下蛋白质的提取率为78.13％.蛋白加工和功能特性显示,在不同pH值条件下,冷榨核桃蛋白的溶解性和乳化活性指数均高于热榨饼粕,但冷榨核桃蛋白的乳化稳定指数低于热榨的；二者的吸水性和吸油性分别为(5.60±0.30)、(4.27±0.16)、(5.70±0.28)和(6.59±0.21)g/g.表明冷榨核桃饼粕分离蛋白质的吸水、吸油性均优于热榨核桃分离蛋白,具有更好的加工特性.另外,二者均具有较好的体外消化特性,但差异不显著(P＞0.05).