NEW TECHNOLOGIES TO PROCESS VALUE-ADDED, HEALTHY FOODS FROM FRUITS AND VEGETABLES
Location: Processed Foods Research
Title: SIMULTANEOUS ROUGH RICE DRYING AND DISINFESTATION WITH INFRARED RADIATION
| Khir, Ragab - UC DAVIS, DAVIS, CA |
| Lewis, Richard - UC DAVIS, DAVIS, CA |
| Godfrey, Larry - UC DAVIS, DAVIS, CA |
| Salim, Adel - SUEZ CANAL UNIV, EGYPT |
| Thompson, James - UC DAVIS, DAVIS, CA |
Submitted to: Proceedings of the American Society of Agricultural and Biological Engineers International (ASABE)
Publication Type: Proceedings
Publication Acceptance Date: May 12, 2006
Publication Date: July 9, 2006
Citation: Zhongli Pan, Ragab Khir, Richard Lewis, Larry Godfrey, Adel Salim, James F. Thompson, J. 2006. Simultaneous rough rice drying and disinfestation with infrared radiation. Proceedings of the American Society of Agricultural and Biological Engineers International (ASABE). Paper No. 066087:1-18. St. Joseph, Mich.:ASAE.
Interpretive Summary: The goal of this research was to develop rapid, non-chemical, safe alternative methods to eliminate insect pests from freshly harvested paddy rice while retaining high rice quality. Alternatives are needed to replace the planned decommissioning of currently licensed pesticides. Infrared radiation was evaluated for its effectiveness in simultaneous drying and infestations, and retaining milling quality of freshly harvested rice. The results showed that the infrared radiation can be used for simultaneous rice drying and disinfestations with high rice milling quality.
The objective of this study was to investigate the drying characteristics, milling quality and disinfestation effectiveness of rough rice under infrared (IR) radiation heating. Freshly harvested medium grain rice (M202) samples with low (20.6%) and high (25.0%) moisture contents (MC) were used for this study. Single-layer rough rice samples (non-infested and infested with the adults and eggs of lesser grain borers (Rhizopertha dominica) and angoumois grain moths (Sitotroga cerealella) were heated for various durations using a catalytic infrared emitter. The effects of tempering treatment and natural and forced air cooling methods on moisture removal, milling quality and disinfestation were also determined. High heating rate and corresponding high moisture removal were achieved by using the IR heating. After heating, tempering increased moisture removal during cooling and improved milling quality of the rice samples. For example, 60 s of IR heating of 20.6% MC rice resulted in 61.2°C rice temperature, 1.7 percentage MC removal during the heating period and additional 1.4% MC removal after tempering and natural cooling. The rice also had 1.9 percentage higher head rice yield than the control sample dried with room air. The heating and tempering treatment also completely killed the tested insects. However, rice samples without tempering or cooled with forced air after tempering had much lower milling quality than the control. Simultaneous drying and disinfestation with high rice milling quality can be achieved by using the catalytic IR to heat the rough rice to 60°C followed by tempering and slow cooling.