益生菌配方奶粉中水分活度的控制

Controlling water activity of probiotics formula powder

为控制益生菌配方奶粉的水分活度,降低益生菌在配方奶粉中的衰减率,采用了干燥粉末法测定不同生产工艺配方奶粉的临界相对湿度。在临界相对湿度条件下,考察配方奶粉水分质量分数和水分活度的关系。结果表明:在25℃条件下,湿法奶粉的临界相对湿度为50%,干法奶粉为40%。在临界相对湿度下,益生菌配方奶粉的水分质量分数和水分活度呈正相关性,当湿法奶粉水分质量分数在2.4%以下,干法奶粉在1.9%以下时,能满足益生菌奶粉的水分活度在0.2以下的要求。

Purpose： Controlling water activity of probiotics formula powder to reduce the attenuation rate of probioticss in formula powder. Methods： The critical relative humidity of formula powder with different production technology was performed by dry powder. In the condi- tion of critical relative humidity, the relationship of moisture content with water activity was investigated. Results： In 25 ℃, the critical relative humiditys of wet processing formula powder and dry processing formula powder were 50% and 40%.And the moisture content was positively related with the water activity. When the moisture contents of wet processing formula powder and dry processing formula powder were below 2.4% and 1.9%, the water activity would conform the requirement of probiotics below 0.2.