OPTIMIZATION OF CRYOPROTECTANTS FOR STREPTOCOCCUS THERMOPHILUS DURING FREEZE-DRYING USING BOX-BEHNKEN EXPERIMENTAL DESIGN OF RESPONSE SURFACE METHODOLOGY

Emirates Journal of Food and Agriculture

Yixin Hui¹  He chen¹  Bowen Zhang¹  Hongchang wan² 

[1] School of Food and Biological Engineering, Shaanxi University of Science and Technology;Shaanxi Yatai Dairy Co., Ltd.

关键词: Streptococcus thermophilus;    freeze-drying;    cryoprotectants;    Box-Behnken experimental design;   

DOI  :  10.9755/ejfa.2016-07-960

学科分类：农业科学（综合）

来源: United Arab Emirates University, Faculty of Food and Agriculture

【 摘 要 】

The strain Streptococcus thermophilus are widely used in the ways of probiotic formulations form or starter culture powder depending on the function of the strain and viability during production process. The pros and cons of freeze-drying on the viability and storage of starter lactic acid bacteria are well documented. In the present study, we focused on the optimization of freeze-drying medium with addition of cryoprotectants for Streptococcus thermophilus. The interactive effects of sucrose, soluble starch and ascorbic acid on the survival rate as well as the viable counts of S. thermophilus during freeze-drying were investigated by Box-Behnken experimental design. The results showed that, with the mixture of 17 g/100mL sucrose, 17 g/100mL soluble starch and 0.4 g/mL ascorbic acid, the viability could be well preserved when freeze-drying was employed. Moreover, the survival rate and viable counts of S. thermophilus were observed to (69.93±0.07) % and (2.79±0.03) ×1011 cfu/g during freeze-drying using the optimal compound cryprotectants, respectively, which verified the adequacy of predicted value 70.19 % and 2.81×1011 cfu/g. Our results demonstrated that the mixture of the cells in the presence of above three cryprotectants before freeze-drying protected S. thermophilus cells from the adverse freeze-drying environment efficiently.

【 授权许可】

CC BY