提高大豆分离蛋白乳化性的工艺优化及性质分析

Optimization of Technology for Improving Emulsifying Properties of Soybean Protein Isolate and Analysis Its Properties

采用三聚磷酸钠(STP)对大豆分离蛋白(SPI)进行磷酸化改性,通过L16(45)正交试验设计和SPSS分析软件对工艺条件进行优化,并对磷酸化改性前后的蛋白样品进行疏水性、红外光谱和电镜扫描(SEM)3方面的分析测定,确认STP对SPI所产生的磷酸化作用。结果表明:4个试验因素对乳化活性(EAI)和乳化稳定性(ESI)的影响顺序为STP添加量>SPI浓度>反应时间>反应温度;适宜的磷酸化反应条件为SPI浓度13%,STP添加量10%,反应温度40℃,反应时间3.5 h。在最适工艺条件下,经磷酸化改性后的SPI产品的乳化活性从0.293提高到0.785,乳化稳定性从17.8提高到26.2,分别提高了168%和47%。

Soybean protein isolate （SPI） was modified by Sodium tripolyphosphate . Phosphorylation reaction conditions were optimized by the orthogonal experiment design and SPSS analysis software. Hydrophobicity determination, FT-IR Spectrum analysis and scanning electron microscope （SEM） analysis were conducted to confirm the phos- phorylation of SPI by STP. The results showed that the order of the influence of the four factors on emulsifying properties was ： the addition level of STP, the concentration of SPI , reaction time and temperature. The optimal phosphoylation reaction conditions were as follows： the concentration of SP! 13% , the addition level of STP 10% , temperature 40℃ and reaction time 3.5h. Under the optimum conditions, the emulsification activity of SPI modified by phosphorylation was increased from 0. 293 to 0. 785. Meanwhile, the Emulsification Stability was increased from 17.8 to 26.2. The optimal technology parameters have an instructive significance for the production of SPI with better emulsifying properties.