MOISTURE DESORPTION OF PADDY BY TWO DIFFERENT POROUS MEDIA: MATHEMATICAL MODELS AND EXPERIMENTAL DATA

摘要

The aim of this work was to study the moisture reduction of paddy by two different adsorbents, tapioca flour and rice husk. The effects of the mixed ratio of adsorbent to paddy, the initial moisture content of adsorbent and the number of times of adsorbent replacement on the moisture desorption of paddy, moisture adsorption of adsorbent and milling qualities were investigated. The mathematical models were developed for predicting the moisture desorption of paddy and moisture adsorption of adsorbent. Experimental one-pass sorption results revealed that the higher mixed ratio and lower initial moisture content of adsorbent provided the higher moisture reduction rate of paddy and gave the higher water adsorption of adsorbent. It was also found that mixed ratio, initial moisture content and the number of times of adsorbent replacement had no obvious effect on percentage of head rice yield and whiteness of milled rice. Page's model was fitted properly with the experimental desorption and adsorption data.