大豆酸溶蛋白/大豆多糖纳米乳液的制备及表征

纳米乳液具有抗沉降和抗乳析动力学稳定性,是提高脂溶性物质的水溶性和生物利用度的有效手段。本论文探索了大豆酸溶蛋白(acid soluble soy protein,ASSP)/大豆多糖(soy soluble polysaccharides,SSP)纳米乳液的制备工艺,系统分析了p H条件、加油量、压力、质量比、热处理等因素对纳米乳液形成以及稳定性的影响。结果表明:在p H 3.0~4.0范围内,酸溶蛋白与大豆多糖质量比1:4,400 bar的压力下,可以很好地包埋5%~20%的油,此时制备的乳液粒径为269.33±2.26 nm,并且储存60天粒径无显著性变化(P0.05)。p H条件、高压以及热处理对乳液的稳定性具有显著影响(P0.05),ASSP/SSP纳米乳液适合食品工业中的酸性介质、高温以及高盐环境下的应用。通过果胶酶水解大豆多糖,对酸溶蛋白/大豆多糖纳米乳液的形态学进行了研究分析,结果表明酸溶蛋白/大豆多糖纳米乳液的微滴表面被多糖覆盖,大豆多糖能够很好地固定在微滴表面并使得纳米乳液微滴稳定和分散。

Preparation and Characterization of Nano-sized Emulsions Produced from Acid-soluble Soy Protein and Polysaccharide Complexes

Due to its superior stability during storage, against aggregation and creaming, nano-sized emulsion is an effective method to improve the bioavailability and solubility of fat-soluble substances. The preparation process of nano-sized emulsion produced from acid-soluble soy protein (ASSP) and soluble soy polysaccharide (SSP) complex were investigated, the effect of changes in pH, oil content, pressure, ASSP to SSP ratio, and temperature on the formation and stability of the resulting emulsions were also analyzed. The results showed that a stable emulsion (i.e. having a mean droplet size of 269.33 ± 2.26 nm) was obtained with 400 bar pressure, pH between 3.0 and 4.0, ASSP to SSP ratio of 1:4, and 5% to 20% oil content; the average droplet size of the resulting emulsion did not change significantly (p > 0.05) after 60 days. In addition, pH values, high pressure, and heat treatment had a significant effect on the emulsion stability (p < 0.05); emulsion prepared from ASSP and SSP complex can be used in acidic medium, high temperature, and high salt concentration in the food industry. Furthermore, the morphology of the emulsion produced from ASSP and SSP complex was also studied through the addition of pectinase. As the complex was well fixed on the surface of the emulsion droplets, the emulsions exhibited excellent long-term stability and dispersion property.