Development of a synbiotic spray-dried tamarillo (Chyphomandra betacea) beverage, in vitro antioxidant activity and simulated gastrointestinal resistance evaluation

Tamarillo is an exotic fruit consumed regionally in Mexico, that contains a considerable amount of bioactive compounds, like antioxidants and fibre. Since its prebiotic potential was recently established, the aim of this work was to encapsulate two probiotic LAB strains with tamarillo extract and maltodextrin (15% and 20%) as encapsulant agents. Two strains at different maltodextrin concentrations (L. casei with 20% maltodextrin and L. plantarum with 15% maltodextrin) demonstrated higher encapsulation efficiency (90.64% and 92.03%, respectively) and viability after in vitro gastrointestinal digestion. Both microcapsules presented satisfactory flow properties and low moisture (4.19% and 3.91%) and water activity (0.32 and 0.33). During in vitro digestion, the total polyphenols content and the antioxidant activity decreased, but the encapsulating material in both treatments maintained an acceptable concentration of these bioactive compounds. The microcapsules were reconstituted to prepare a synbiotic non-dairy beverage, and both treatments presented good acceptability (7.66 and 7.86 overall acceptance scores, respectively). These results indicate that, first, L. casei and L. plantarum recovered from heat shock during spray drying, enhancing their ability to survive to acidic stress during in vitro digestion; second, tamarillo extract is a good source of antioxidants and prebiotics and can be reconstituted to formulate, in this case, a synbiotic beverage to improve nutritional concern of consumers.