Effect of Microencapsulation on the Viability of Lactobacillus Acidophilus and Saccharomyces Boulardii Probiotics at Different Storage Temperatures in Doogh

Background: Encapsulation of probiotics in a carrier material is a useful tool to improve the viability, release, delivery of probiotic cells and extend food shelf by holding extra multiplying of probiotic cells to prevent changing the sensory characteristic of supplemented food. This study aimed to determine the effects of microencapsulation on the viability of Lactobacillus acidophilus and Saccharomycess boulardii probiotics in Doogh samples stored at different temperatures and their combined effect on pH, stability, and sensory attributes of Doogh samples.   Methods: Micro-encapsulation of probiotics was done using the emulsion method under sterile conditions. Enumeration of probiotics and physical analysis (pH, stability, and organoleptic characteristics) of ۱۲۰ heated Doogh samples containing free and encapsulated L. acidophilus and S. boulardii probiotics were conducted for ۲۸ days at ۷-day intervals (۰, ۷, ۱۴, ۲۱, ۲۸ days) at three temperatures (۴, ۲۰, ۳۵ °C). Results: The survival of probiotics decreased continuously at all temperatures during storage time except for the encapsulated forms of L.acidophilus at ۴ and ۲۰ °C and the free forms of S. boulardii at ۴ °C remained constant significantly (P <۰.۰۵). The treatments containing free S. boulardii had the least significant decrease in pH on the last day of storage at ۲۰ and ۳۵ ºC temperatures. The sensory evaluation shows acceptable scores in all treatments stored at ۴ °C.  Conclusion: Our results show synergistic effects of encapsulated probiotics on extending the shelf life of Doogh.

Keywords:

Acidified milk drink , Encapsulation , Probiotic , Shelf-life , viability