Co-encapsulation of bioactive compounds from blackberry juice and probiotic bacteria in biopolymeric matrices

Abstract

Blackberry juice (BJ) and Lactobacillus acidophilus (LA) were co-encapsulated by spray drying in three single materials: gum Arabic (GA), maltodextrin (MD) and whey protein concentrate (WPC), as well as in the 50:50 blends of these materials were also considered. After the spray drying, total phenolic compounds (TPC) and total monomeric anthocyanin content (TMAC) was higher when GA-MD blend was used as an encapsulating agent with 98.4 ± 1.0% and 99.0 ± 1.0%, respectively. FTIR analysis indicated that the BJ affected the structure of the wall material, mainly when WPC was incorporated. The viability of LA was significantly higher when WPC was used (93.3 ± 0.9%) in comparison with a single material or a blend of materials. After storage of microcapsules, the best blend of biopolymers to protect TPC and TMAC was GA-MD with values of 67.9 ± 0.6% and 81.8 ± 0.8% respectively, while WPC presented the highest protection in LA cell survival (81.2 ± 0.7%). The degradation dynamics of compounds in microcapsules was described by first-order kinetics, with degradation rates ranging between 0.06 and 0.30 week−1 for bioactives and probiotic bacteria. The overall results showed GA-MD can be considered the most viable formulation to protect bioactives and probiotic bacteria.