Asian Research Journal of Current Science

Pineapple is a widely consumed tropical and subtropical non-citrus fruit because of its pleasant flavour, refreshing balance of sweetness and acidity, and high vitamin C content. The objective of this study was to optimise the osmotic dehydration conditions of pineapple cubes using Response Surface Methodology (RSM) by evaluating the effects of solution temperature, immersion time, and sucrose solution concentration on water loss (WL), weight reduction (WR), and solid gain (SG). A Central Composite Rotatable Design (CCRD) was employed with solution temperature ranging from 32 to 48°C, immersion time from 40 to 141 min, and sucrose solution concentration from 42 to 58 °Brix. A constant sample-to-solution ratio of 1:5 was maintained throughout the osmotic dehydration process. Quadratic regression models were developed for WL, WR, and SG, and all models were statistically significant (p < 0.001). Among the investigated process variables, immersion time had the greatest influence on all three responses, followed by sucrose solution concentration and solution temperature. Numerical optimisation was performed by maximising WL and WR while minimising SG. The optimum conditions were determined as a solution temperature of 45°C, an immersion time of 119 min, and a sucrose solution concentration of 55 °Brix. Under these optimum conditions, the experimentally validated WL, WR, and SG values were 22.30%, 10.70%, and 14.58%, respectively, with an overall desirability of 0.74. These results demonstrate that RSM can be effectively applied to identify suitable operating conditions for the osmotic dehydration of pineapple cubes within the investigated experimental range.