Spray‐process optimization for the encapsulation of probiotic Lactobacillus acidophilus ATCC 11975 in a ternary wall matrix

Abstract

The inlet air temperature and feed flow rate of a spray drying process were optimized for encapsulation of Lactobacillus acidophilus ATCC 11975 using a ternary wall matrix of skim milk powder, maltodextrin, and cellulose acetate phthalate. The combined effect of inlet air temperature (140, 150, and 160℃) and feed flow rate (2.0, 2.5, and 3.0 ml/min) was studied on the encapsulation efficiency (EE), survival rate (SR), moisture content (MC), recovery yield (RY), and water activity (aw) by creating response surface plots in a full factorial design. A significant (p < .05) decrease in EE, SR, MC and aw, and increase in RY values of the powder were noticed by increasing the temperature and decreasing the feed rate. The optimum conditions to produce maximally viable probiotic powder were 145℃ and 2 ml/min. The shape of the particles was spherical. Thermal characterization revealed a better storage stability with a low inactivation rate. Practical applications Achieving a higher survival rate of probiotics to confer adequate health benefits to human gut is the prime concern of this research which was successfully achieved by optimizing the spray drying parameters. This manuscript details the potential application of a ternary wall matrix composite consisting of skim milk powder, maltodextrin, and cellulose acetate phthalate to successfully encapsulate the probiotic strain of Lactobacillus acidophilus, with improved encapsulation properties. The study will help towards formulating a novel dairy-based probiotic food with enhanced gut microbiota by generating the necessary background data required.