Effect of osmotic dehydration on some physicochemical parameters of dried pineapple slices

Osmotic dehydration is one of the processes that contribute to the increase in sensory value and shelf life of the product. This study aimed to investigate the influence of osmotic dehydration on the physicochemical parameters of pineapple fruit, which was harvested in Can Tho City, Vietnam. The parameter range of sugar content in the osmotic dehydration solution from 400 to 600 g/L and the temperature factor from 18 to 38°C (±1℃) during osmotic dehydration were investigated. Osmotic dehydration time was investigated until osmotic equilibrium appeared. The effects of the stir condition during osmotic dehydration were monitored and compared with conventional osmotic dehydration. The indicators of moisture content and sugar content in raw materials were evaluated after each hour of osmotic dehydration. The color difference (rE) was also investigated for some osmotic dehydration samples. The results showed that osmotic dehydration at 38°C and sugar content was 600 g/L under the support of continuous stirring for the best osmotic dehydration effect. Study results have provided an overview of the whole process of osmotic dehydration at different concentrations of osmotic solutions. These results were the basis for flexibly choosing conditions for osmotic pineapple in accordance with the purpose of each product (e.g. jelly) and consumer demand (e.g. sweetness level).