the study of carboxymethyl cellulose-ascorbic acid based edible coating and osmotic dehydration on cucurbit drying

in this study, the effect of edible coating and osmotic dehydration, as pre-treatments before drying of cucurbit, were investigated. cucurbit samples were cut spirally and coated by carboxy methyl cellulose (cmc) 1% and ascorbic acid 0.1% solutions and then processed by osmotic dehydration. proportion of sample to solution was 1:10 and the solution containing sucrose %45, salt%25 and citric acid %1 (w/w) was selected as the best osmotic solution. finally, the cucurbit samples were dried by oven (at 80 ˚c for 3 hours). the effects of cmc based coating on water loss (wl), solid gain (sg), immersion time, amount of salt, sucrose, citric acid absorption and color and sensory acceptability of samples were evaluated. the results showed that cmc based coating decreased sg without decreasing effect on wl which in turn decreased drying time of osmotic dehydrated samples in oven. furthermore, the coated, osmotic dehydrated samples showed higher color quality and sensory acceptability in comparison to the control samples.