Beetroot Extract Encapsulated in Inulin: Storage Stability and Incorporation in Sorbet

Abstract

Betacyanin is a natural colorant extracted, principally, by beetroot, being a good alternative to substitute synthetic colorant, because it not shows toxic effect and established daily intake rate. However, betacyanin is instable to conditions of heat, light and oxygen. The objective of this study was to encapsulate beet root extract, by spray drying, using inulin as encapsulating agent. The study proposed also, the incorporation of colorant microcapsules in sorbet. Solutions of microcapsules (10%) and beet root extract (control) were prepared and storage at 4° and 25°C, and sob influence of light and absence of light. The stability of colorant was determined by betacyanin quantification, by spectrophotometry. Sorbet was prepared with incorporation of microcapsules and beet root extract (control), and color stability of sorbet was evaluated during 6 months of storage at -18°C. Encapsulation efficiency was 58.4%. A linear relationship was observed from the plots of the betacyanin content versus time, implying first-order reaction kinetics for beetroot extract and microcapsules degradation. For all conditions evaluates, it was observed that the highest rate constant was obtained by microcapsules solutions, i.e., microencapsulation was not effective to protect the beet root extract. However, color stability of sorbet prepared with beet root microcapsules was higher than compared to sorbet prepared with beet root extract. All the samples of sorbet had good acceptance in the sensory analysis, with acceptance index higher than 80%.