Location: Healthy Processed Foods Research
Title: Effectiveness of Infrared Radiation for Rough Rice Disinfestations Authors
|Khir, Ragab - UC DAVIS, DAVIS, CA|
|Lewis, Richard - UC DAVIS, DAVIS, CA|
|Godfrey, Larry - UC DAVIS, DAVIS, CA|
|Thompson, James - UC DAVIS, DAVIS, CA|
|Salim, Adel - UC DAVIS, DAVIS, CA|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: December 20, 2005
Publication Date: N/A
Interpretive Summary: The research goal was to develop a rapid, non-chemical, safe alternative method using infrared heating to eliminate insect pests from storage rough rice. The alternative is needed to replace the planned decommissioning of currently registered pesticides. The objective of this project was to study the effectiveness of infrared heating for disinfestations. The results showed that infrared heating can be used for rough rice disinfestation by heating the rice to 60 degrees C with 3 h tempering.
Technical Abstract: The ultimate goal of this research was to develop a rapid, non-chemical, safe alternative method using infrared heating to eliminate insect pests from storage rough rice. The alternative is needed to replace the planned decommissioning of currently registered pesticides. The objective of this project was to study the effectiveness of infrared heating for disinfestations. The storage rice, medium grain (M202), with moisture content of 11.0% was used for the study. Each 250 g rice sample was infested with 100 adult lesser grain borers, Rhizopertha dominica, and 50 adult angoumois grain moths, Sitotroga cerealella, at 18 and 6 days before the thermal treatment to produce larvae and eggs of the insects in the sample. The infested rice samples were heated on a single-layer bed using a catalytic infrared emitter with the radiation intensity of 5300 W/m2 and five exposure times from 10 to 30 s. The final temperatures of heated rice were in the range of 46 degrees C to 67 degrees C. After heating the samples were held at the heated temperature for various times, up to 3 h, and then cooled gradually to a room temperature. The moisture losses of the rice samples caused by the heating were calculated based on the weight losses. The heat treated samples were then stored at 27 degrees C, 60% RH, and in continuous darkness for 38 days to observe the effectiveness of disinfestations. It has been found that lesser grain borers were more heat-resistant than angoumois grain moths. The recommended minimum disinfestations temperature was 60 degrees C, which caused the reductions of 0.6 percentage points in total rice yield and 0.3 percentage points in head rice yield for the rice samples with 3 h tempering. The treatment also caused 0.53% moisture loss.