Effect of osmotic dehydration pre‐treatments on physicochemical and energy parameters of Kosia (Nashi) pear slices dried in a convective oven

Abstract

In this study, the effects of osmotic dehydration pre-treatments in sucrose solutions on dried Kosia pear slices were determined. The effective diffusion, modeling, color, rehydration, specific energy consumption, specific moisture extraction rate (SMER), evaporation latent heat, energy efficiency (EE), convective heat (hc), and mass transfer coefficient (hm) parameters of fruit slices were investigated. The shortest drying time (17 h) was observed in the drying process of the samples subjected to osmotic dehydration in 25% sucrose solution for 1 h. The best thin-layer drying models were identified as Lewis (R2: .9977) and Jane-Das (R2: .9977) models. Effective diffusion values ranged between 2.13–4.94 × 10−5 m2 s−1. Rehydration ratios ranged between 2.09 and 2.71 g g−1 while rehydration capacities ranged between 57.24% and 63.05%. The least color change was observed in control samples. SMER values of the dried samples ranged between 0.0062–0.00011 kg kWh−1. EE values ranged between 4.19% and 0.03%. Mass transfer coefficient values varied between 1.57 × 10−8 and 1.06 × 10−12 m/s. Heat transfer coefficient value was calculated as 5.773 × 10−7 W m−2 K. Uncertainty that stems from measurements and cannot be controlled was calculated as ±2.324%. Novelty impact statement High sucrose solution ratios of drying pre-treatments reduced the drying time of Kosia pear slices. Control samples retained their color values better. Samples subjected to osmotic dehydration in 25% sugar solution for 1 h had is the optimum values drying performance and energy parameters.