Characteristic changes in brown rice (Oryza sativa L.) cultivars of 3 ecotypes during different storage conditions

Abstract

The aim of this study investigated the fluctuations of 3 characters from 3 ecotypes [early ripening (ER), middle ripening (MR), and late ripening (LR)] of 20 Korean brown rice cultivars in different storage systems [time: 12 and 24 weeks, temperature: low (10oC) and room (25oC)]. With increase of storage time and temperature, lipoxygenase activity, and fat acidity increased, whereas germination rate was reduced. ER cultivars exhibited the highest lipoxygenase activity of 35.49±2.46 unit/mg protein during 24 weeks storage at 25oC, followed by LR (32.73±1.33) and MR (32.66±1.62) cultivars. The amounts of fat acidity also were observed by the same order (ER: 20.40±2.12>LR: 19.68±1.86>MR: 19.64±1.35 mg KOH/100 g). Germination rate slightly decreased with increase of time and temperature (MR>LR>ER), but MR and LR cultivars showed the most significant changes (ER: 60.90±23.47%, MR: 32.66±13.95%, and LR: 32.53±5.87%). On the basis of above results, MR cultivars were evaluated the highest quality, because high lipoxygenase activity, high fat acidity, and low germination rate have deteriorated in quality and generated off-odor. Thus, MR cultivars might be very important sources in food processing and stored dietary supplement aspects. ? The Korean Society of Food Science and Technology.