Response surface optimization of osmotic dehydration process for aonla slices.

Response surface methodology was used to investigate the effect of sugar concentration (50-70° Brix), solution temperature (30-60°C), solution to fruit ratio (4:1-8:1) and immersion time (60-180 min) on the water loss, solute gain, rehydration ratio, vitamin-C loss, colour change and sensory overall acceptability of Indian gooseberry (aonla) slices. The optimum process parameters obtained by computer generated response surfaces, canonical analysis and contour plot interpretation were: sugar concentration, 59° Brix solution temperature 51°C, solution to fruit ratio 4:1 and immersion time of 60 min.