Effect of cryoprotectants on freeze drying of lactic acid bacteria

Lactic acid bacteria play a key role in fermentation processes and are used commonly as starter cultures in fermented foods. Because of industrial applications of lactic acid bacteria as starter cultures or probiotics cultures, it needs to maintain survival microbial populations that depend greatly on used preservation methods. Nowadays, freeze drying is the most common preservation method for industrial microbial cultures. Although, there is loss cell survival in this method. Inactivation of freeze-dried starter cultures depend mainly on freezing stage. The choice of protective agent type has direct effect on survival of microorganism. In this review, the advantages of freeze drying, stages, effective factors on survival, protective mechanisms during freeze drying, evaluation of protective agent performance and types of protective agents will be discussed

Keywords:

lactic acid bacteria , starter culture , freeze drying , protective agent