INVOLVEMENT OF SOME PROCESS VARIABLES IN MASS TRANSFER KINETICS OF OSMOTIC DEHYDRATION OF PAPAYA SEGMENTS

A study was conducted at ICAR RC NEH Region, AP Centre, Basar, Arunachal Pradesh, to evaluate the effect process variables viz., Water loss (WL), solid gain (SG) and mass reduction (MR) on osmo-dehydration of papaya segments. Ready to use osmo-dehydrated papaya slices which are light in weight can be prepared successfully from firm and ripe papaya fruits. 1.5 cm thick, 10 cm length, 4 cm breadth papaya segments were dipped in sucrose solution of different concentrations (20, 30, 40 and 50°Bx) with varying temperatures (20, 25, 30 and 40°C) containing 0.05% KMS and 0.1% citric acid. The ratio of the fruits and osmotic solution was maintained at 1:4 ratios, in order to ensure proper soaking of the samples with agitation. Samples were withdrawn at regular interval (1.5, 3, 4.5 and 6 h), drained quickly and wiped gently with tissue paper. All experiments were carried out in triplicate and average values were reported. The results indicated that water loss, solid gain and mass reduction were found to increase with increase in sucrose concentration and temperature of the solution at the end of osmosis. The optimum solid gain (9.8%), water loss (33.8%) and mass reduction (22.7%) were recorded at 40°Bx sucrose solution with 30°C temperature. Besides, osmotic drying considerably increased sugar content and reduced acidity with no significant change to colour, texture and original flavour of the fruits. Regression analyses of different parameters (immersion time, temperature and concentration) of osmosis were found to be significant. Descriptive analysis on sensory attributes revealed that process variables significantly affected the sensory characteristics of papaya segments.