高温豆粕大豆分离蛋白射流空化辅助提取

Extraction of Soy Protein Isolate from Highly Denatured Soybean Meal by Jet Cavitation Assisted

为高效提取高温豆粕中大豆分离蛋白,利用射流空化辅助提取高温豆粕中大豆分离蛋白,并进一步研究射流空化压力(0~2.0MPa)对大豆分离蛋白提取率、二级结构、持油性及持水性、溶解度、起泡性及乳化性等性质的影响。结果表明,射流空化处理样品的游离巯基含量、蛋白质表面疏水性均显著高于未经处理的样品(P<0.05),而二硫键含量显著降低(P<0.05)。当射流空化压力1.5MPa时,大豆分离蛋白提取率为58.97%,比未处理样品提高了34.42%;大豆分离蛋白的持油性及持水性、溶解度、起泡性和乳化性均得到显著改善,表明射流空化处理使蛋白质分子解折叠,结构展开,暴露出更多的游离巯基,蛋白颗粒粒径减小,比表面积增加,有利于改善大豆分离蛋白的功能特性。当射流空化压力增加到2.0MPa时,高压作用及极端热导致大豆分离蛋白的功能特性下降。将提取大豆分离蛋白与商品大豆分离蛋白的功能性质进行比较,表明射流空化处理工艺可提高高温豆粕中蛋白质的利用价值。

The process of extraction soy protein isolate from highly denatured soybean meal by alkali lytic acid precipitation method with the aid of jet cavitation was aimed to increase the yield of protein. The effects of different jet cavitation powers(0~2.0 MPa)on soy protein isolate extraction rate, secondary structure, oil-holding capacity and water holding capacity, solubility, foaming and emulsifying properties were further studied. As the results shown, the free sulfhydryl contents and the surface hydrophobicity of the samples treated by jet cavitation were significantly higher than those of the untreated samples ( P <0.05), while the disulfide bond contents were significantly decreased ( P <0.05). When the jet cavitation power was 1.5 MPa, the extraction rate of soy protein isolate was 58.97%, which was 34.42% more than the untreated sample. The oil-holding capacity and water holding capacity, solubility, foaming and emulsifying properties of soy protein isolate were significantly improved. The results indicated that the jet cavitation treatment unfolded the protein molecules, stretched the structure, exposed more free sulfhydryl groups, decreased the particle size of the protein particles, and increased the specific surface area, which was beneficial to improve the functional properties of soy protein isolate. When the jet cavitation pressure was increased to2.0 MPa, the high pressure and extreme heat decreased the functional properties of soy protein isolate. At the same time, the functional properties of the extracted soy protein isolate and commercial soy protein isolate were compared, the results characterized the jet cavitation process in improving the utilization value of protein in high temperature soybean meal.