Research On Rice Drying Quality & Tri-Stage Drying Method

Jiangsu province is one of the main producing provinces of rice and wheat.There has been a large volume of research on inventing a method that can dry grains efficiently and guarantee the proper quality of the grains as well.In this research,common species of rice and wheat in Jiangsu province were studied to observe their drying curves and drying rate curves.High moisture paddy rice had been also tested during the accelerated storage time after dried by different levels of hot-air temperature.Tri-stage drying conditions had been optimized for improving the efficiency of drying and the rice quality.And the Tri-stage drying method had been then applied in wheat drying for the first time.The main contents and results of the research are as follows:a.The drying curves and drying rate curves had been obtained by observing the changes of rice’s and wheat’s moisture content along with the time,and the changes of rice’s and wheat’s drying rate along with the their timely moisture content.The inner part of rough rice（brown rice）had been also analyzed,and we found that shell of rough rice had a negative impact on the rice drying procedure.b.Both drying and storage procedure could have a negative impact on rice.In this research,a greater influence had been found exerting by storage time.This discovery might have a positive impact on comprehending the mechanism of drying conditions affecting the deterioration of rice during subsequent storage time more completely.c.In order to get an appropriate Tri-stage drying process condition,both single factor experiment and response surface method were used to optimize the drying process.Four factors were engaged in this study（air temperature inⅠstage（X1）,moisture content afterⅠstage drying（X₂）,storage time for the Ⅱstage（X3）and air temperature in Ⅲ stage（X4））.And a model was established based on principal component analysis method for assessing and ranking the drying quality of rice,and the model was also used as an objective index to optimize to Tri-stage Drying process.The Optimization results were as follow: X1: 76.30 ℃,X2: 19.99%,X3: 11.34 d,X4: 35.53 ℃.d.The Tri-stage drying method had been then applied in wheat drying for the first time,and air temperature inⅠstage（W1）were suggested set as 75⁸5 ℃;moisture content afterⅠstage drying（W2）were suggested set around 22%;air temperature in Ⅲ stage（W3）were suggested set as 60⁶5 ℃.