Modeling the Effect of Inulin, pH and Storage Time on the Viability of Selected Lactobacillus in a Probiotic Fruity Yogurt Drink Using the Monte Carlo Simulation

Abstract

AbstractThe effects of pH (5.5, 5.75, 6 and 6.75) and inulin concentration (0, 0.5, 1 and 2%) on the survival of Lactobacillus casei 431 and Lactobacillus acidophilus LA‐5 in pomegranate yogurt drink during 21 days refrigerator storage at 4C were studied. A polynomial multiple regression equation was used in Monte Carlo simulation to predict the probiotic viability. The model fitted well with experimental data (for L. casei R2 = 0.90 and L. acidophilus R2 = 0.96). Also, sensitivity analysis was applied to identify most substantial factors affected the viability. Through the probability distribution, it was demonstrated that L. casei accommodated to manipulation of the environmental conditions (pH and % inulin) while L. acidophilus failed at the end of shelf life and fell down below the critical number of 106 cfu/mL. The Monte Carlo simulation can be a useful device to estimate the amount of viable probiotic bacteria exist in final product.Practical ApplicationsIn this study, a functional beverage was produced because the viable probiotic cells are known to be beneficial for human body when sufficient amounts (at least 106 cfu/mL) of probiotic bacteria are carried through dairy products. Monte Carlo simulation can be a robust predictive model in practical industrial applications and in research to make reliable statements about the survival/inactivation of probiotic bacteria when the formulation is changed. Also, this tool makes the industries able to determine the best time to consume a probiotic product to uptake adequate amount of useful microorganisms by the end consumer.