Osmotic Dehydration of Pineapple Stems in Hypertonic Sucrose Solutions

摘要

The present study provides the evaluation in the influence of the variables: temperature (T), concentration of the osmotic solution (C) and ratio of fruit and osmotic solution (F:OS) during the osmotic dehydration of slices of pineapple stem variety Perola, on the responses: water loss (WL), mass loss (ML), gain of solids (GS) and ratio of gain of solids and water loss (GS/WL). The centesimal composition was determined both in the raw material and in the dehydrated product. To optmize the process, the studied factors were: temperature (T), with factorial points -1 equal to 30°C and +1 equal to 50°C;concentration of sucrose solution (C), with factorial points -1 equal to 40 g·100 g-1 and +1 equal to 60 g·100 g-1 and ratio of fruit and osmotic dehydration solution (F:OS), with factorial points -1 and +1 equal to 1:20 and 3:20, respectively. In all essays, the dehydration time was 4 hours. The essays showed that F:OS was not significant in any responses;the models adopted were predictive and fitted for WL and ML, and reasonable for GS and GS/WL. The temperature was the most significant variable in the process;the optimized values were: T= 50°C, C = 40 g 100 g-1 e F:OS = 3:20. The product needs a complementary drying to adapt itself to the legislation demands.