Microencapsulation May Preserve the Viability of Probiotic Bacteria During a Baking Process and Digestion: A Case Study with Bifidobacterium animalis Subsp. lactis in Bread.

Abstract

The high sensitivity of probiotic bacteria (PB) to many environmental factors limits the number of food products where they can be incorporated. This study aimed to examine the capability of a unique three-layered microcapsule structure to protect PB against extremely elevated temperatures and low pHs to allow their incorporation into bakery goods. The microcapsules were prepared first by granulation of a Bifidobacterium lactis (BL) strain, as a model PB, to form a core, and then coating the core with three consecutive protective layers. The physical features and the shape of the microcapsules obtained from three sequential preparations were characterized using various methods. A viable cell count was utilized to evaluate the efficiency of the microcapsule structure to protect the bacteria during a bread-baking process carried out at 180°C for 40min and also during the exposure to simulated gastric fluid (pH 1.2) for up to 1h. The results showed that whereas the free bacteria (unprotected BL) encountered a significant viability loss under these conditions, the microencapsulated BL presented superior resistance.