Optimization of process parameters for osmo-mechanical dehydration of shelled peas (Pisum sativum)

For optimization of osmotic pretreatment process of shelled peas prior to mechanical drying at 60°C temperature to safe moisture content of 10% (w.b.), experiments were planned in Box and Behnken design using response surface methodology. The independent process variables for osmotic pretreatment process were osmotic solution concentrations (5–15%w/v sodium chloride), osmotic solution temperature (30–60°C) and immersion time (60–180 min) with constant solution to pea ratio (4:1 v/w). The osmotic pretreatment process was optimized for maximum water loss, overall acceptability, texture (firmness), rehydration ratio and minimum solute gain and colour change. The optimum conditions were 14.99% salt concentration, 30°C osmotic solution temperature and 115.67 min immersiontime. An analysis of variance (ANOVA) revealed that, among the process variables, concentration had the most significant effect on water loss, solute gain, rehydration ratio, overall acceptability and texture (firmness); solution temperature had the maximum effect on colour change. Immersion time was observed to have significantly lower effect on responses.