Optimization of Spray Drying Encapsulation of Bioactive Compounds from Organic Blueberry Extract

Abstract

In this study, the effects of spray drying parameters on organic blueberry extract were investigated. High amounts of bioactive compounds were extracted from blueberry by solvent extraction. Response surface methodology was applied for the optimization of spray drying conditions. Extract mass percentage of feed mixture (m/m in dry basis 15-50%), air inlet temperature (120-150°C) and solid content of feed (20-40°Brix) were independent variables. Operational efficiency (yield) and phenolic retention were responses. Maltodextrin was used as an encapsulating agent. The optimum extract mass percentage, temperature and solid feed content were estimated as 19.51% (m/m) extract, 120°C and 20.03°Brix, respectively. The maximum levels of responses under optimum conditions were obtained as operational efficiency of 91.20% and phenolic retention of 87.12%. It was found that the most important variable for bioactive compound retention was the extract mass percentage. Encapsulated powder had 3.19% moisture content, and contained 5.54 mg gallic acid equivalents (GAE), 1.52 mg cyanidin-3-glucoside (C3G), and 46.41 μmol Trolox equivalents (TE) per gram dry powder. DPPH free radical scavenging activity value (EC50) of powder was 8.14 mg soluble solids/mL. Bioactive powder obtained could be considered as a possible functional food ingredient. In conclusion, blueberry extract powder could be efficiently produced by spray drying.