番茄红素油多层乳状液的制备及稳定性研究

Studies on the Preparation of Lycopene Multilayered Emulsion and Stability Evaluation

番茄红素是一种具有多种生理功能的天然类胡萝卜素,它不溶于水,且结构特殊、不稳定。将番茄红素油制成多层乳状液,有望改善其溶解性和稳定性。本文以大豆分离蛋白、果胶和壳聚糖作为聚电解质,采用静电层层自组装的方法制备番茄红素油多层乳状液,探讨聚电解质浓度、pH、乳化速度等因素对乳状液稳定性的影响,以确定制备番茄红素油多层乳状液的最佳条件。研究表明,在pH3、乳化速度15 000 r/min、番茄红素油含量0.5%、大豆分离蛋白含量1%的条件下,制备的初级乳状液乳层保留率为90%;在pH3、番茄红素油含量0.25%、大豆分离蛋白含量0.5%及果胶含量0.05%的条件下,制备的二级乳状液乳层保留率达到92%;在pH3、番茄红素油含量0.125%、大豆分离蛋白含量0.25%、果胶含量0.025%及壳聚糖含量0.05%的条件下,制备的三级乳状液乳层保留率达95%。制备番茄红素油多层乳状液可以显著提高番茄红素的稳定性,本研究为提高番茄红素的溶解性和分散性奠定了理论基础。

Lycopene is a natural carotenoid with multiple physiological functions. Lycopene is characterized by its poor water solubility and stability as well as a special structure. Transformation to a multilayered emulsion form is expected to improve its solubility and stability. The lycopene multilayered emulsions were prepared by using soybean protein isolate(SPI), pectin, and chitosan as the polyelectrolytes through electrostatic layer-by-layer self-assembly. The effects of polyelectrolyte concentration, pH and emulsifying speed on emulsion stability were investigated to determine the optimum conditions for multilayered emulsion formation. The results indicated that the optimum conditions for primary emulsion formation were emulsifying speed 15 000 r/min, lycopene concentration 0.5%, SPI concentration 1.0% and pH 3.0.Such conditions yielded emulsion retention of 90%. The optimum conditions for the secondary emulsion formation were lycopene concentration 0.25%, SPI concentration 0.5%, pectin concentration 0.05% and pH 3.0, which led to emulsion retention of 92%. The optimum conditions for the preparation of the tertiary emulsion were lycopene concentration 0.125%, SPI concentration 0.25%, pectin concentration 0.025%, chitosan concentration 0.05% and pH 3.0. Under such conditions, the emulsion retention peaked as high as 95%. It was concluded that the formation of multilayered emulsion could significantly improve the stability of lycopene and this work laid the theoretical foundation of improving the solubility and stability of lycopene.