Instant vegetable from osmo-air drying of jimikand (A. campanulatus) in NaCl solution: nutritional, functional, micro-structural and other quality aspects.

Abstract

The aim of this work was to study the effect of osmotic dehydration on the quality of jimikand which can be used as an instant vegetable to get its nutritional and functional benefits. Osmotic dehydration was applied as pre-treatment to hot-air drying for increasing palatability, mass transfer improvement and minimizing nutritional losses. To see the effect of osmotic dehydration on various quality parameters, conditions of osmotic dehydration selected were osmotic solution concentrations (5, 10 and 15% w/w) and temperatures (40, 50 and 60°C) for constant process time (80min) on the basis of mass transfer analysis. The observed values of hardness, oxalate content and water activity of osmo-dried samples varied from 66.04±14.5 to 79.12±14.8N, 60.0±0.40 to 69.1±0.65mg/100g, 0.911±0.001 to 0.826±0.001, respectively, and found less as compared to fresh sample, i.e. 131.12±9.5N, 110.5±0.78mg/100g and 0.990±0.00 respectively. Rehydration ratio of fresh sample was 3.52±0.03 and varied from 2.82±0.06 to 3.57±0.10 for osmo-dried samples being higher at lower concentrations and temperatures. The best conditions of osmotic dehydration found were 10% NaCl, 50°C temperature and 80min duration on the basis of appreciable mass transfer, lowest oxalate content, water activity, better rehydration, textural and sensory quality. The selected osmo-dried sample was better due to low anti-nutritional content, less micro-structural damage and appreciably comparable to fresh hot-air dried in terms of total phenol, antioxidant activity, and other quality parameters.