Influence of whey on viability of Lactobacillus gasseri during freeze-drying process

Probiotic bacteria have positive impacts on a numerous of physiological functions including immunomodulation and also on prevention of various intestinal diseases. However, acidic environment of the stomach and heavy conditions of freeze-drying process decrease survival of these bacteria. There are necessary researches on cheap raw materials that increase cell protection. The aim of the present study was to determine the impact of whey and other compounds on survival Lactobacillus gasseri during the freeze-drying process and storage. There were prepared culture media for cell protection during lyophilisation, which contained a variety of mixture whey, skim milk, sucrose, starch, maltodextrin and whey protein. Lyophilisate was rubbed in aerobic and anaerobic condition with lower humidity. Survival tests were investigated directly after freeze-drying process and then periodically during storage under refrigeration. Within 6 months of storage bacterial viability was similar in the samples containing liquid whey except for media containing starch. The results of viability did not deviate than those obtained with using the reference medium, which contains skim milk and sucrose. This shows that the liquid whey may be successfully used to protect the lactic acid bacteria during lyophilisation. Moreover, the use of whey can reduce the amount of waste produced in the dairy industry.