Abstract: With the increasing demand for health, probiotic lactic acid bacteria are finding increasingly wide application in the fields of food and medicine. Spray drying, as a commonly used method to prepare a lactic acid bacterial powder, has the advantages of high efficiency and sustainability, but it exposes lactic acid bacteria to adverse factors such as high temperature, dehydration, and oxidation. Studies have shown that using stress treatment and exogenous addition of trehalose can improve the spray drying resistance of lactic acid bacteria, but there were currently only a few studies. Stress treatment can trigger the protective mechanism of lactic acid bacteria, enhancing their tolerance. Trehalose, as a natural protective agent, can stabilize the cell membrane structure, preserve protein integrity, and thus improve the resistance of lactic acid bacteria. More importantly, stress treatment can increase intracellular trehalose accumulation in lactic acid bacteria, and can also introduce exogenous trehalose into the cells, thereby improving the spray-drying resistance of lactic acid bacteria. This finding lays a theoretical foundation for the preparation of a highly active lactic acid bacterial powder.

Key words: lactic acid bacteria; stress treatment; trehalose; spray drying resistance; synergistic effect