Spray drying of strawberry and blueberry extracts

In this study, the effects of spray drying parameters on blueberry and strawberry extracts were investigated. Response surface methodology was applied to optimize spray drying conditions. Maltodextrin DE 8 was used as encapsulating agent (wall material). Feed flow rate and air flow rate were kept constant. Air inlet temperature (120-150⁰C), extract mass percentage in the feed mixture (m/m in dry basis 15-50 %) and feed mixture (20-40 ⁰Brix) were the independent process variables. The responses of model were operational efficiency and phenolic retention. The optimum conditions of spray drying were based on the maximum levels of responses. The optimum temperature, extract mass percentage and feed mixture were estimated as 120⁰C, 23.26 % (m/m) extract, 20.00 ⁰Brix for strawberry and 120⁰C, 19.51 % extract, 20.03 ⁰Brix for blueberry, respectively. The maximum levels of responses under optimum conditions were obtained as operational efficiency of 91.95 %, phenolic retention of 79.62 % for strawberry and operational efficiency of 91.20 %, phenolic retention of 87.12 % for blueberry. It was found that the most important variable was extract mass percentage in production of blueberry and strawberry extract powders. Key Words: Spray drying, encapsulation, berry, maltodextrin, response surface methodology