Microencapsulation of Lactobacillus strains

Abstract

The microencapsulation technique has been an alternative for the stabilization of probiotic bacteria because the encapsulating matrix provides a physical barrier against several factors that affect the viability of probiotics, including pH, bile salts, oxygen and storage temperature. The objective of this work was to evaluate different matrices: whey powder (W), whey powder with inulin (WI) and whey powder with maltodextrin (WM) in the microencapsulation of two probiotic potential strains Lactobacillus brevis CCMA 1284 and Lactobacillus plantarum CCMA0359 by spray drying. Viability of the microencapsulated strains in acid and bile juices and during 90 days of storage to 7 and 25 °C were evaluated. The two strains of Lactobacillus sp. microencapsulated with different matrix combinations resulted in high encapsulation efficiency (> 86%). The different matrices maintained the viability of L. plantarum CCMA0359 above 6 log CFU/g at 7 °C for 90 days, while only the L. brevis CCMA 1284 microparticles formulated with S presented similar results. L. brevis CCMA 1284 showed greater sensitivity to acid and biliary conditions than L. plantarum CCMA 0359. The spray drying microencapsulation technique was successfully used for microencapsulation of Lactobacillus sp. strains. Based on the results of the encapsulant matrix and the strain, whey powder and L. plantarum CCMA 0359 were selected for application of the microparticles in the requeijão. The survival of free and microencapsulated cells of Lactobacillus plantarum CCMA 0359 added in requeijão were determined during storage period at 7 °C for 90 days, as well as in simulated gastrointestinal condition. The effect of the bacteria addition in the sensorial properties of the requeijão was also evaluated. The L. plantarum CCMA 0359 population (microencapsulated and free cells) remained around of 8 log CFU/g during all storage time, however, the counts for microencapsulated cells were slightly higher than free cells. The addition of bacteria (microencapsulated and free cells) increased the acidity and decreased the pH of requeijão during storage, and microencapsulated cells showed more pronounced alterations of acidity and pH. Under simulated gastrointestinal condition, the microencapsulation technique allowed a significant higher protection of cells. The addition of L. plantarum CCMA 0359 (free and microencapsulated cells) to the requeijão did not affect the acceptance of the product by the consumers. The requeijão showed to be an alternative vehicle for the potential probiotic L. plantarum CCMA 0359, without affect the acceptance of the product.