期刊名称：Annals of the University Dunarea de Jos of Galati. Fascicle VI : Food Technology
印刷版ISSN：1843-5157
电子版ISSN：2068-259X
出版年度：2015
卷号：39
期号：1
页码：70-80
出版社：Galati University Press
摘要：Lactobacillus bulgaricus is the bacteria commonly used in probiotic dairy product,including yogurt and cheese. The bacteria may be stored for long periods of timeif it is freeze-dried. The cryoprotectant mixture for L. bulgaricus was optimizedduring the process of freeze-drying using a Plackett-Burman design and thesteepest ascent test. In our initial tests, the cell survival rate and the number ofviable cells were associated with the type of cyroprotectant used. Therefore, ouroptimization protocol focused on increasing survival rate. Substances thatpreviously had a protective effect during freeze-drying were investigated, forexample: sucrose, lactose, skim milk powder, sodium bicarbonate, sodiumglutamate, magnesium sulfate, sodium ascorbate, yeast extract, vitamin B2, andphosphate buffer. We determined that the optimum cryoprotectant composition forL. bulgaricus consists of 28.0 g/100 mL skim milk powder, 24.0 g/100 mL lactoseand 4.8 g/100 mL sodium ascorbate. The optimized cryoprotectant provides a63.25% cell survival rate.
