Development and Optimization of Attapulgite Clay Based Microencapsulation for Lactic Acid Bacteria by Response Surface Methodology.

Lactic acid bacteria (LAB), screened and purified from the fermented yogurt, were microencapsulated in sodium alginate (SA) and attapulgite composite microcapsules by external gelation to increase their viability and stability. Surface characterization by scanning electron microscope clearly evidenced a high number of the LAB embedded in SA/attapulgite composite microcapsules than SA counterparts due to a more cohesive structure, and biocompatible microenvironment. SA/attapulgite and CaCl2/attapulgite composites analysis revealed a better embedding effect of attapulgite blend with SA solvent compared with attapulgite mixed with CaCl2. Influence of three major factors including SA, calcium chloride, and attapulgite concentration on LAB embedding rate were optimized by "single factor strategy" as well as response surface methodology (RSM). Optimal conditions of these factors obtained by RSM were SA (1.03 %), Attapulgite (0.28 %), and CaCl2 concentration (1.17 %). The related embedding rate was predicted as 87.1369 %, and the actual measured value was 91.24 % by experiments using the optimal conditions. In conclusion, the results revealed that LAB microencapsulation in the SA and attapulgite composite might display noteworthy protection against the gastrointestinal environment. [ABSTRACT FROM AUTHOR]