Optimisation of osmotic dehydration process for aonla (Emblica officinalis) fruit in the mixture of salt-sugar solution

Abstract

The osmotic dehydration of aonla fruit was carried out to optimize the time of the osmosis in the mixed solution of sugar and salt at the room temperature. The destined aonla fruits with and without blanching were immersed in the mixture of salt and sugar solution. The salt concentration of the osmotic solution was kept constant (100 g) and the sugar concentrations were varied to bring the concentrations to 35, 45 and 55o Brix maintaining a fruit to syrup ratio of 1:3 by weight. The observations were recorded to study the influence of osmotic solution and time on water loss and solid gain. The results of osmotic dehydration showed the maximum water loss of 48.55 per cent recorded for blanched fruit osmosed at 55o B and the minimum (27.61%) in unblanched fruit osmosed at 35oB. The solid gain also was observed to be maximum (23.4%) in the blanched fruit compared to unblanched fruit (9.94%) at respective concentrations. The optimization process carried out using Design expert software showed the highest desirability of 0.785 for blanched aonla fruit osmosed at 55 oB.