Oven microencapsulation of lactobacillus delbrueckii ssp. bulgaricus using spray drying gellan-maltodextin mixtures

Abstract

The aim of this work was to evaluate the ability to keep Lactobacillus delbrueckii ssp bulgaricus, viable in microencapsules obtained from mixtures of gellana gum and maltodextrin, using the spray-driyng. The study was conducted in three stages: the flow behavior of the dispersion of mixtures of maltodextrin and gellan gum (GM), in the second stage the operation variables of the process were evaluated, and finally the functionality of the microorganism microencapsulates using gellan gum and maltodextin mixtures was studied. The dispersions of gellan gum-maltodextrin were prepared at concentrations of 0.5-0.5%, 0.75-0.25% and 0.25/0.75% (w/w) in deionized water. The GM dispersions showed a non-Newtonian behavior, shear thinning type. The operation variables of spray drying process were flow feed 44.52 x10^-5 m³/s, air velocty of 5.02 m/s, pressure of 15 psi and spray drying temperature of 160 ºC. The microcapsules prepared from GM dispersions: 0.50-0.50% showed the most largest diameter (17.3 µm) and the GM: 0.25-0.75% showed the most smaller diameter (8.04 µm). The microcapsules obtained with the GM: 0.50-0.50% allowed fermentation times very closed to non-microencapsulated bacteria system.