TiO2-大豆蛋白复合膜保鲜草莓的研究

Studies on Fresh-keeping Strawberry Using TiO_2/SPI Composite Film

采用正交试验设计优化Ti O2-大豆蛋白复合涂膜制备的工艺条件,测定其抗菌性能。用Ti O2-大豆蛋白复合涂膜低温贮藏草莓,测定贮藏过程中各组草莓的失重率、总菌落数、可溶性单糖及颜色等指标的变化情况。结果表明,最优工艺条件:Ti O2添加量2.00 g/150 m L,大豆分离蛋白和甘油质量浓度分别是4.50 g/150 m L和3.75g/150 m L。Ti O2-大豆蛋白复合膜对大肠杆菌和金黄色葡萄球菌均有很好的杀灭效果。经过涂膜处理的草莓在-4℃下贮藏8 d,失重率比空白组降低17.3%,总菌落数减少97.0%,颜色及可溶性单糖含量的变化比空白组稳定,说明Ti O2-大豆蛋白复合膜可有效延长草莓在低温下的贮藏时间。

In this paper, the orthogonal test was designed to optimize the preparation conditions of TiO2/SPI compos- ite film, and its antibacterial properties were measured. The optimized TiO2/SPI composite film was applied in strawberry at low temperature, and the weight loss rate, the total number of colonies, the soluble monosaccharide and color were measured during storage. The results showed that the optimum condition was as follows： the TiO2 dosage 2.00 g/150 mL, the SPI concentration 4.50 g/150 mL and the glycerol concentrations 3.75 g/150 mL. The optimized TiO2/SPI composite film can restrain the growth of E. coli and S. aureus. After 8 days storage at -4 %, strawberries coated with the TiO2/SPI composite film had lower weight loss rate by 17.3% and lower total bacterial count by 97.0% than that uncoated with film. Besides, changes of color difference and soluble monosaccharide content are steadier than the controls. The results proved that the storage period of strawberries was prolonged at low temperature by coating optimized TiO2/SPI composite film.