Survival and stability of free and encapsulated probiotic bacteria under simulated gastrointestinal and thermal conditions

Abstract

ABSTRACT The core objective of the current study was to assess the effect of encapsulation on the viability and stability of probiotic bacteria under simulated gastrointestinal digestion and thermal conditions. Purposely, probiotics were encapsulated with hydrogel matrices (sodium alginate and carrageenan) using encapsulator. Furthermore, developed microbeads were characterized by X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR) spectroscopy to elucidate the interaction between hydrogel matrices and probiotics. The viability of probiotics assessed by subjecting to simulated GIT and thermal conditions. Encapsulation exhibited a significant (p< .05) effect on the survival and stability of probiotics. Overall, a decreasing trend in viability of probiotics was observed in all treatments. A rapid log reduction was observed when free probiotic cells were stored at refrigeration temperature compared to encapsulated probiotic bacteria. Likewise, in vitro gastrointestinal assay, only 3 log while in case of non-encapsulated bacteria 6 log reduction was recorded. In short, the results of the viable count in the case of encapsulated cells were above recommended level (106 cfu/g) under thermal as well as in GIT conditions.