Effect of Pre-treatments and Drying Methods on Dehydration and Rehydration Characteristics of Carrot

Abstract

The study was conducted to evaluate the effect of pre-treatments (0.1%KMS, 0.2%KMS, 0.3%KMS and blanching) and drying methods (mechanical drying and solar drying) on the dehydration and rehydration characteristics of carrot. The two drying methods yielded dehydrated products with different dehydration ratio, rehydration ratio, coefficient of reconstitution and moisture content in both the dehydrated and rehydrated materials. It was seen that the drying time has been influenced by pre-treatments and drying methods. Pre-treatments increased drying time (for 0.3%KMS) and higher drying time (for 0.3%KMS) was required in solar drying. Pre-treatment, drying methods and boiling time affected the various rehydration properties. Highest rehydration ratio (3.70) and coefficient of reconstitution (0.48) values were found for 0.1% KMS pre-treated mechanically dried and 0.2% KMS pre-treated solar dried carrots, respectively. Mechanical drying method was found better both for dehydration and rehydration properties for all the pre-treatments for example, 0.1%KMS pre-treated carrot gave coefficient of reconstitution 0.48, while this value was 0.45 for same pre-treatment in solar drying.