响应曲面分析法研究挤压对大豆蛋白和果胶混合物乳化性能的影响

Influence of Extrusion on Emulsifying Properties of Soybean Proteins and Pectin Mixtures Modelled by Response Surface Methodology

采用单体重心设计应用到新型乳化活性指数(EAI),平均液滴尺寸(D[4,3])以及混合物乳状液分层(CI%)中。用响应曲面分析法去预测含有分离和组织化的大豆蛋白与果胶混合物的乳化能力和稳定性以及对挤压过程是否影响这些界面性能进行评价。结果显示,所有模式均显著,并能解释86%以上的变异。该模型较高的预测能力也被证实。EAI,D[4,3]和CI%的平均值在所有的试验中分别是(0.173±0.015)nm,(19.2±1.0)μm和53.3%±2.6%。在3种化合物之间没有任何协同作用被检测到。这个结果可能归因于在p H值为6.2(<35%)时大豆蛋白低的溶解性。胶质是对于改善所有反应中最重要的变量。挤压后混合物的乳化能力增加了41%。研究结果表明,胶质能代替或者提高大豆蛋白的乳化能力,而挤压则带来该种组合界面性能的新的优势。

A simplex-centroid design was applied to the model emulsifying activity index( EAI),average droplet size( D[4,3])and creaming inhibition( CI%) of the mixtures. The objective was to apply response surface methodology to estimate the emulsifying capacity and stability of mixtures containing isolated and textured soybean proteins combined with pectin and to evaluate if extrusion process affects these interfacial properties. Results showed that all models were significant and able to explain more than 86% of the variation. The high predictive capacity of the models was also confirmed. The mean values for EAI,D[4,3]and CI% observed in all assays were( 0. 173 ± 0. 015) nm,( 19. 2 ± 1. 0) μm and 53. 3% ± 2. 6%,respectively. No synergism was observed between the three compounds. This result could be attributed to the low soybean protein solubility at p H 6. 2( <35%). Pectin was the most important variable for improving all responses. The emulsifying capacity of the mixture increased41% after extrusion. Pectin could substitute or improve the emulsifying properties of soybean proteins and that the extrusion brought additional advantage to interfacial properties of this combination.