Predicting the stability of freeze-dried Lacto-bacillus bifidus by the accelerated storage test

Abstract

In an accelerated storage test the logarithms of the number of surviving freeze-dried Lactobacillus bifidus declined linearly with time at three selected temperatures (36°, 45°, and 6°C). The logarithms of the calculated rates of decline in the number of organisms at elevated temperatures were in a linear function with the reciprocals of absolute temperatures (Arrhenius relation). The obtained results make it possible to predict the rate of degradation at any temperature by extrapolation of the tested results which accord with of the number of organisms for storage at +4°C was in accordance with the actual value after prolonged storage. Based on the above results, the authors believe in applicability of the accelerated storage test in predicting the stability of freeze-dried suspensions of bacteria.