Encapsulation of Lactobacillus acidophilus La-5 and Bifidobacterium Bb-12 by spray drying and evaluation of its resistance in simulated gastrointestinal conditions, thermal treatments and storage conditions/ Encapsulacao de Lactobacillus acidophilus La-5 e Bifidobacterium Bb-12 por spray dryer e avaliacao da sua resistencia em condicoes gastrointestinais simuladas, tratamentos termicos e em condicoes de armazenamento

Lactobacillus acidophillus La-5 (ML) and Bifidobacterium Bb-12 (MB) microparticles were produced at different temperatures by spray dryer. The influence of different temperatures on the viability, encapsulation efficiency, water activity and moisture were evaluated. Microparticles that presented more viability were submitted to thermal resistance, gastrointestinal simulation, storage stability, morphology and particle size analyses. Drying temperature of 130[degrees]C showed higher encapsulation efficiency, 84.61 and 79.73% for Lactobacillus acidophillus (ML) and Bifidobacterium Bb-12 (MB) microparticles, respectively. In the evaluation of thermal resistance and gastrointestinal simulation, the microparticles of Lactobacillus acidophillus La-5 (ML) presented higher survival than Bifidobacterium Bb-12 (MB) under these conditions. In storage viability only the Lactobacillus acidophillus La-5 (ML) microparticles remained viable at all evaluated temperatures during the 120 days. The particle sizes reported were 4.85 for Lactobacillus acidophillus La-5 (ML) and 8.75 for Bifidobacterium Bb-12 (MB), being in agreement with the desired values for products obtained by spray dryer. Finally, the Lactobacillus acidophilus La-5 (ML) microparticles were shown to be more resistant under the conditions evaluated in this study. Key words: spray dryer, viability, probiotics. Microparticulas de Lactobacillus acidophillus La-5 (ML) e Bifidobacterium Bb-12 (MB) foram produzidas em diferentes temperaturas de secagem no spray dryer. A influencia das diferentes temperaturas sobre a viabilidade, eficiencia de encapsulacao, atividade de agua e umidade foram avaliadas. As microparticulas que apresentaram maior viabilidade foram submetidas a analises de resistencia termica, simulacao gastrointestinal, estabilidade ao armazenamento, morfologia e tamanho de particula. A temperatura de secagem de 130[degrees]C mostrou maior eficiencia de encapsulacao, 84.61 e 79.73%para microparticulas de Lactobacillus acidophillus (ML) e Bifidobacterium Bb-12 (MB), respectivamente. Na avaliacao da resistencia termica e simulacao gastrointestinal as microparticulas de Lactobacillus acidophillus La-5 (ML) apresentaram maior sobrevivencia que Bifidobacterium Bb-12 (MB) nestas condicoes. Na viabilidade ao armazenamento somente as microparticulas Lactobacillus acidophillus La-5 (ML) mantiveram-se viaveis em todas as temperaturas avaliadas durante os 120 dias. Os tamanhos de particula encontrados foram de 4.