Effect of different microencapsulating materials on the viability of S. thermophilus CCM4757 incorporated into dark and milk chocolates

Abstract

This study aimed to evaluate the viability and bioaccessibility of Streptococcus thermophilus CCM4757 strain supplemented in dark and milk chocolates during storage period and pass through simulated in vitro gastro-intestinal tract. Microencapsulated and non-microencapsulated S. thermophilus CCM4757 strain added into the chocolates. Emulsion technique was used to microencapsulate cells with various biopolymers; carboxymethylcellulose, pectin, gum arabic, and cellobiose. The microencapsulated S. thermophilus with these coating materials was found to be viable higher than 9 log CFU/g up to 180 days of storage at 4 °C. Microbiological, physicochemical, and sensorial attributes of the chocolates containing microencapsulated and non-microencapsulated S. thermophilus CCM4757 were analyzed. The microencapsulated S. thermophilus showed a good survivability in milk (7.12 log CFU/g) and dark (6.90 log CFU/g) chocolate samples during 180-day storage at 4 °C. Supplementation of S. thermophilus did not affect significantly (P > 0.05) the sensory attributes of the chocolates. The results showed that S. thermophilus CCM4757 exhibited good cell survivability higher than 85% in chocolates under simulated gastro-intestinal fluids. S. thermophilus supplementation into the chocolate protected the viability of cells and did not affect the sensorial characteristics and moisture content of chocolates. The present study demonstrated that the dark and milk chocolates could be used as an important matrix to carry probiotics. © 2021 Elsevier Ltd