Study on Moisture Transport and Shrinkage Phenomena in Drying of Root Vegetables

Abstract

The high-quality and high-efficient drying technique is important in the field of food-processing. The purpose of this study is to clarify the mechanism of moisture transport and shrinkage phenomena in the drying of root vegetables. We use two kinds of drying methods, the micro vacuum drying and the warm air drying. Experimental study was made with the Japanese radish, the carrot and the potato. It is confirmed that the shrinkage rate increases during the falling-rate period in both drying methods. It is also found that the central part of potato has a possibility to cause a glass-transition due to lower moisture content in the micro vacuum drying. This may be a reason for that a shrinkage is suppressed in the potato.