Comparative Viability of Spray Dried Lactobacilli Affected by Different Protective Agents and Storage Conditions

Abstract

Because of their health benefits, probiotics are a significant part of the functional food industry. Spray drying is reported as the most common method used in the food industry to encapsulate probiotics. The objectives of this study were to investigate the effects of protective agents on the viability of lactobacilli after spray drying and during storage at different conditions and to evaluate spray drying conditions to produce these probiotic powders. Lactobacillus plantarum NRRL B-4496 (LP) and Lactobacillus acidophilus NRRL B-4495 (LA) were separately grown (~109 CFU/ml) and suspended in a 200 g/L solution of high maize starch (HM); maltodextrin (MD); or gum arabic (GA). The solutions were separately spray dried at 140 °C to obtain LP and LA-powders: LPHM, LPMD, LPGA, LAHM, LAMD, and LAGA. The powders were separately placed in aluminum bags and separately packed under 97% and 10% vacuum. The powders were stored at refrigerated (4 °C) or at room (23 °C) temperature for 60 days. Physicochemical properties, energy and mass balances, and cell viability during storage were determined. Triplicate experiments were conducted and data were statistically analyzed (α=0.05). The actual production rate of powders ranged from 0.091 to 0.105 (kg dry solids/h). The energy used during spray drying was not significantly different for any of the powders. After 60 days, LPHM powders packed under 10% and 97% vacuum and stored at 4 °C had significantly higher cell viability than the other powder samples. The study demonstrated significantly improved on the viability of LP at 10% vacuum stored at refrigerated temperature for the HM treatment compared to those treated with MD and GA. The data obtained showed that high maize starch can be used as a protective agent to maintain the viability of L. plantarum powder at recommended levels for up to 60 days of storage.