Journal of Food Engineering, Vol.92, No.1, 107-111, 2009
Effect of coating on post-drying of freeze-dried strawberry pieces
Although the color, flavor and taste of freeze-dried (FD) strawberries pieces are very good, texture collapse after rehydration limits the application of FD strawberry pieces in liquid carriers. In this work, the effects of coating the freeze-dried pieces and the drying method after coating are investigated. The best formula for the coating solution is found to be: whey protein 10%, glycerol 3%, lactose 10%. Color of strawberry pieces can be protected to some extent by adding Na(+) and beta-Cyclodextrin (beta-CD) in the coating solution. The best proportions of Na(+) and beta-CD were 3 mg/ml and 0.5 mg/ml, respectively. Coated freeze-dried pieces of strawberry were dried in a spouted bed. The rehydration characteristics of the coated strawberry pieces were found to be influenced by the coating time as well as the drying conditions used. (C) 2008 Elsevier Ltd. All rights reserved.