ASABE Technical Library - Abstract
Member and Access Notice
EFFECTS OF DRYING AND TEMPERING RICE USING A SINGLE PASS DRYING PROCEDURE
Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan www.asabe.org
Citation: Paper number 036039, 2003 ASAE Annual Meeting . (doi: 10.13031/2013.13906) @2003Authors: Terry J. Siebenmorgen
Keywords: Rice, drying, glass transition temperature, head rice yield
The objective of this research was to determine the effects of various drying and tempering
strategies on rice quality using a continuous drying procedure. The drying procedure used was designed
to implement a hypothesis involving the glass transition temperature of rice as applied to moisture content
removal rates and tempering durations. The drying procedure consisted of four stages. First, rice was
dried in a chamber for various durations aimed at removing 1 to 6 percentage points of moisture content.
The rice was then sealed in plastic bags and tempered inside the drying chamber for certain durations, as
determined in previous research, to reduce moisture content gradients within the kernels. The rice was
then dried further to approximately 12 to 13% moisture content. After this second drying stage, the rice
was again tempered.
There was little to no reduction in head rice yield when less than 4 to 5 percentage points of
moisture content were removed during the first drying stage. Conversely, if drying exceeded 4 to 5
percentage points removal, there was a significant reduction in head rice yield; additionally, tempering
did not prevent head rice yield reduction under these drying scenarios. Also, if less than 4 to 5 percentage
points were removed during the first drying stage, then drying could continue after sufficient tempering
without head rice yield reduction.