Rice Quality Preservation during On-Farm Storage Using Fresh Chilly Air

A new technique for storing rice at a temperature below ice point using fresh chilly air was developed. Freezing temperatures and extents of freezing injury of rice with various levels of moisture content were studied, and effects of temperature below ice point during a four-year storage period on the physiological properties of rice were investigated. Rice with moisture content of less than 17.8% did not freeze even at a temperature of -80°C. Low temperature maintained the vitality of rice, minimized physiological activities and starch deterioration in rice, and preserved rice quality. One thousand tons of rough rice was stored in two silos from the end of November 1999 and was aerated from the bottom to top of each silo using fresh chilly air in January 2000. The rough rice temperature fell below ice point. At the end of July 2000, the rough rice temperature in the center of each silo was still below ice point. The rice quality stored in the silos was preserved at a level similar to that of freshly harvested rice. A combination of rice storage below ice point and utilization of fresh chilly air enables the rice quality to be preserved at a high level without the requirement of a cooling unit or electricity. The use of this storage technique has been increasing in cold regions after the on-farm experiment. In Hokkaido, the northernmost island in Japan, 26 grain-elevators have been constructed since 1996. The storage capacity of rough rice was 115,000 t at the end of 2003.Proceedings of "International Quality Grains Conference : a Global Symposium on Quality-Assured, Traceable and Biosecure Grains and Oilseeds for the 21st Century" in July 19-22, 2004.http://www.iqgc.org

Accuracy of Near-infrared Transmission Spectroscopy for Determining Rice Constituent Contents and Improvement in the Accuracy

The accuracy in determination of rice constituent contents using a commercial near-infrared transmission (NIRT) instrument was validated. And the accuracy of measurements using this instrument was improved by modifying light filters and calibration equations used in the instrument. In the determination of moisture content, the coefficient of determination (r2) was 0.98, standard error of prediction (SEP) was 0.13%, and bias was -0.02%. In the determination of protein content, r2 was 0.90, SEP was 0.17%, and bias was 0.01%. These results show that the newly developed instrument is sufficiently accurate to be used instead of reference analysis for measuring moisture content and protein content of brown rice. An automatic rice-quality inspection system was designed. The system consisted of a rice huller, a rice cleaner, an NIRT instrument and a visible light (VIS) segregator. Based on rice-quality information, this system enables rough rice transported to a rice grain elevator to be classified into six qualitative grades.Written for presentation at the 2002 ASAE Annual International Meeting / CIGR XVth World Congress Sponsored by ASAE and CIGR Hyatt Regency Chic

Development of On-farm Storage Technique for Rice at Temperature below Ice Point Using Ambient Naturally Cold Air in Winter

The objective of this project was to develop a new on-farm storage technique for rice at a temperature below ice point using ambient naturally cold air in winter. In an on-farm storage experiment, 994 tons of rough rice was stored in two silos from the end of November 1999, and the rough rice was aerated from the bottom to the top of each silo for 91 hours in January 2000. The rough rice temperature in each silo fell down below ice point (minus 1.5 degrees Celsius on average). At the end of storage (end of July 2000), the temperature of rice grains in the center of each silo was kept still below ice point (minus 0.5 degrees Celsius). The quality of the rice stored in the silos was thereby preserved at a level similar to that of freshly harvested rice. A combination of rice storage at a temperature below ice point and utilization of ambient cold air in winter enables the quality of rice to be preserved at a high level without the requirement of a cooling unit or electricity.Written for presentation at the 2001 ASAE Annual International Meeting Sponsored by ASA

Development of a New Technique for Fine Sorting of Brown Rice by Use of a Combination of a Thickness Grader and a Color Sorter

A research project was conducted to develop a new technique for fine sorting of brown rice by the use of a combination of a thickness grader and a color sorter in order to increase sorting yield and improve rice quality. It was found that a greater sorting yield and processed rice of high quality can be obtained by reducing sieve slot width of the thickness grader by 0.10 mm from the conventional standard slot width and then removing immature, damaged and discolored kernels by the combined use of a color sorter. By using the brown rice fine sorting technique developed in this study, rice farmers’ income can be increased and high -quality rice can be supplied to consumers.Written for presentation at the 2007 ASABE Annual International Meeting Sponsored by ASAB

Development of a System for Fine Cleaning of Rough Rice for High-Quality Storage

Bulk rough rice after drying consists of sound whole kernels, immature kernels, empty kernels, damaged kernels, hulled kernels and foreign materials such as straw, weed seed and dust. Fine cleaning of rough rice is an important step after drying to improve rough rice quality and to minimize quality deterioration of rough rice during storage. We developed a system for fine cleaning of rough rice. The system consists of a wind separator, gravity separator and indented cylinder separator. The wind separator removes straw, weed seed, dust and empty kernels by means of an air stream. The gravity separator discharges four streams of material: a mixture of sound whole kernels and hulled kernels; good rough rice product (mostly sound whole kernels); a mixture of sound whole kernels, damaged kernels and immature kernels, which is returned through the wind separator and gravity separator to achieve a complete separation; and a mixture of damaged kernels, immature kernels and empty kernels that is removed from the line. The indented cylinder separator removes hulled kernels from the mixture of sound whole kernels and hulled kernels discharged from the gravity separator. The sound whole kernels separated by the indented cylinder separator are mixed with the good rough rice product from the gravity separator. The fine cleaning system developed in this study enables separation and removal of immature kernels, empty kernels, damaged kernels and hulled kernels and therefore improvement in rough rice quality. The fine cleaning system has been in practical use in Japan.Written for presentation at the 2006 ASABE Annual International Meeting Sponsored by ASAB

Development of an automatic rice-quality inspection system

The need has arisen in rice-drying facilities in Japan for an automatic method to measure quality aspects of rice when it arrives at the drying facility. A near-infrared (NIR) transmission instrument was used to obtain NIR spectra of damp rough rice and damp brown rice. Calibration models were developed from the original spectra and reference analysis data to determine moisture and protein content of the samples. A visible light (VIS) segregator was used to determine sound whole kernel of brown rice. The precision and accuracy of the NIR instrument and the VIS segregator were found to be sufficiently high to determine moisture and protein content, and sound whole kernel ratio. An automatic rice-quality inspection system was consequently developed. The system consisted of a rice huller, a rice cleaner, an NIR instrument and a VIS segregator, and it was controlled by a computer. Based on the rice-quality information, this system enabled rough rice transported to a rice-drying facility to be classified into six qualitative grades