Encapsulation of Extract from Unused Chokeberries by Spray Drying, Co-crystallization, and Ionic Gelation

Abstract

The objective of this work is to optimize a new method of unused chokeberries application in food industries, based on the encapsulation by spray drying, co-crystallization, and ionic gelation of their phenolic extract. For each method, the effects of various parameters on efficiency and yield were studied and the optimum operating conditions were predicted. In the spray drying method, the optimum values of encapsulation efficiency (99.6%) and yield (31.9%) were achieved with a ratio of wall to core of 9.0, an air temperature of 190 °C, an air rate of 19.25 m3/h, and maltodextrin:skim milk powder (50:50) as encapsulating agent. The optimum efficiency of co-crystallization (96.3%) was achieved with a solids concentration of extract of 35 oBrix and a ratio of dry extract to sucrose of 0.7. In the ionic gelation, the optimum conditions (efficiency of 94.2%) were: concentration of sodium alginate solution of 2.0% w/w, concentration of calcium chloride solution of 2.5% w/v, and concentration of extract of 20.0% w/w. Powders encapsulated at the optimum conditions were analyzed for moisture content, bulk density, wetting time, hygroscopicity, color, sorption isotherm, release kinetics, and morphology. Furthermore, the antioxidant capacity and stability of the extracts were evaluated during storage.