Comparison of Kinetics and Other Related Properties of Bamboo Shoot Drying Pretreated with Osmotic Dehydration

摘要

Osmotic dehydration (OD) of bamboo shoots were carried out at 50°B sucrose syrup and 10% salt using temperature and time of 40C and 90 min, respectively. These shoots were dried at temperatures of 45, 55 and 65C using three drying methods viz., tray drying, vacuum drying and fluidized bed drying. Drying kinetics and other related properties at all three temperatures were studied and exponential model were fitted. R 2 values were found above 0.9 and k values were increased with temperature. Rehydration ratio was found more for osmo–vacuum-dried (OD–VD) shoot; however, it was high at 55C. Firmness and shrinkage were also reported more for vacuumed-dried shoot. Microstructure of bamboo shoots were mostly affected by the drying methods. “L” values for OD–VD method were found slightly less whereas “a” and “b” value were found high compared with other drying methods. Shoots treated with OD–VD at 55C were found acceptable. Practical Applications Bamboo shoots have been widely used as an ideal vegetable in diet because of its high dietary fiber, low fat content and potential medicinal applications; however, because of seasonal availability of shoots, its processing and preservation viz., drying, canning, fermentation, packaging, etc., are necessary for long-time storage. Reduction in total drying time can be achieved by application of osmotic dehydration as a pretreatment. This study will help to understand the drying kinetic of osmotically dehydrated bamboo shoot by tray, fluidized bed and vacuum drying method at different temperatures. It will also provide the best combination of drying methods and temperature along with osmotic dehydration condition for achieving better product quality in terms of rehydration ratio, color, texture, etc.