Freezing Temperature and Freezing Injury of Rough Rice, and Quality of Rough Rice Stored at Temperatures between -50°C and 25°C for Four Years
Year: 2005
Type: conference-paper
Abstract: A differential scanning calorimeter was used to determine freezing temperature of roughrice. Rice grains with a moisture content of 22.1% froze at about 35C. Rice grains with a moisturecontent of less than 20.8% did not freeze at a temperature of 55C. Incidence of freezing injury ofrice grains was determined by germination rate because grains that suffered from freezing injury didnot germinate. Rice grains with a moisture content of less than 17.8% germinated after being storedat 80C for 11 days. Thus, no grain with a moisture content of less than 17.8% froze at atemperature of 80C. Effects of temperatures between 50C and 25C on physiological properties and qualitycharacteristics of rough rice during four-year storage were investigated. Low temperature maintainedvitality of rice, minimized physiological activities, starch deterioration and rancidity in rice, andconsequently preserved rice quality. Eating quality of rice stored at temperatures less than 5C forfour years was the same as that of newly harvested rice. These results indicate that preservation ofrough rice quality for several years is possible by storing rice at an average temperature below 5Cduring storage. A new on-farm rice storage technique at temperatures below ice point by usingnatural fresh chilly air in winter has been in practical use in Hokkaido, the northernmost island ofJapan, in recent years. Twenty-six grain elevators have been constructed in Hokkaido since 1996.The storage capacity of rough rice in 2004 was 115,000 t.
Source: 2005 Tampa, FL July 17-20, 2005
DOI: 10.13031/2013.19540
Authors: Shuso Kawamura, Kazuhiro Takekura, Mio Yokoe
Institution: Hokkaido University
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W2092551276