Wang Yuxian, Liu Xian, Shao Yufeng, Guo Yaozu, Gu Ruixia, Wang Wenqiong
College of Food Science and Engineering, Yangzhou University, Yangzhou 225127, China.
Foods. 2024 Jul 17;13(14):2260. doi: 10.3390/foods13142260.
The effects of MRS, whey protein and blueberry alone, and mixed fermentation on the survival rate of lactic acid bacteria under various freeze-drying conditions were investigated. The surface structure of the freeze-dried powders was also investigated to explore the anti-freezing protection mechanism of mixed whey protein and blueberry fermentation on the bacteria. It was found that the mixed fermentation medium of blueberry and whey protein has a protective effect on the freeze-drying bacteria and is better than the traditional MRS and whey protein medium. The optimal concentration of blueberry juice addition was 9%. The survival rate of the pre-freezing temperature at -80 °C was higher than at -20 °C after the pre-freezing and freeze-drying processes. The freeze-drying thickness of 0.3 cm could improve the survival rate of the bacteria. The Fourier transform infrared spectroscopy results indicated the interaction between the whey protein, anthocyanins, and the surface composition of the lactic acid bacteria.
研究了MRS、乳清蛋白和蓝莓单独以及混合发酵对不同冻干条件下乳酸菌存活率的影响。还对冻干粉末的表面结构进行了研究，以探索混合乳清蛋白和蓝莓发酵对细菌的抗冻保护机制。结果发现，蓝莓和乳清蛋白的混合发酵培养基对冻干细菌具有保护作用，且优于传统的MRS和乳清蛋白培养基。蓝莓汁的最佳添加浓度为9%。预冻温度为-80℃时，预冻和冻干后的存活率高于-20℃。0.3 cm的冻干厚度可提高细菌的存活率。傅里叶变换红外光谱结果表明了乳清蛋白、花青素与乳酸菌表面成分之间的相互作用。
