The effect of the high temperature and short time (HTST) drying stage was combined with an air drying process to produce crispness in bananas. The fruit was dehydrated in an air drier for five minutes at 70 degrees C and then immediately set at a HTST stage (130, 140, 150 degrees C and 9, 12, 15 minutes) and then at 70 degrees C until water activity (a(w)) was around 0.300. Crispness was evaluated as a function of water activity, using sensory and texture analyses. Drying kinetics was evaluated using the empirical Lewis model. Crispy banana was obtained at 140 degrees C-12min and 150 degrees C-15min in the HTST stage, with a(w) = 0.345 and a(w) = 0.363, respectively. Analysis of the k parameter (Lewis model) suggests that the initial moisture content of the samples effects this parameter, overcoming the HTST effect. Results showed a relationship between sensory crispness, instrumental texture and the HTST stage.
展开▼
