Effect of Drying Methods on Physico-chemical And Sensory Characteristics of Osmodehydrated Sweet Potato Slices and Their Storability

Abstract

Key words : Sweet potato, Osmotic dehydration, Tray drying, Solar drying, Drying rate, Moisture content, Sensory Evaluation. The main objective of this study was to compare the pre-treated sweet potato slices (Ipomoea batatas) dried by different drying m13thods (tray drying and solar drying) and its quality evaluation. Fresh sweet potato were washed and cut into pieces of 2 mm and 4mm thickness and 500 gm weight. These slices were osmotically dehydrated in different concentration (30 & 40°8) ,process temperature(60°C),solution to sample ratio (10:1) and Immersion time (120 Minutes).The pretreated samples were dried in tray dryer at 60°C and solar drying. It can be concluded from this study that solution temperature, sugar concentration and duration of osmosis were the most pronounced . factors affecting water loss of sweet potato slices during osmotic dehydration. From the study it can be seen that tray drying of 6 hrs at 60°C is sufficient to achieve a desirable physico-chemical properties of sweet potato slices. But there v.1ere slight decrease of values due to variation in syrup concentration. In cac;e of solar drying for 8 hr it was also found to achieve desirable physico-chemical properties but the values found were slight higher than those dried by tray dryer. The overall acceptability was found to be higher for tray dryer for 60°C at 40°8 (syrup concentration) than those of solar because in osmo-solar dried samples, non-uniform drying was observed