Effects of Fertilizer Levels on Amount and Quality Contents of Rice Bran Oil in New japonica Rice Varieties with Large Embryo in North Western Region of Vietnam

Abstract

Background: Rice bran oil is produced from rice bran, which contains nutrients such as oryzanol, lecithin, tocopherols and tocotrienol. The potential rice varieties for rice bran oil or brown rice production are the Ja23 and Ja35 lines developed by the Vietnam National of Agricultural. Using nitrogen with different levels of doses has been shown to increase photosynthesis, dry matter accumulation and seed yield in rice plants. Therefore, this study was conducted to evaluate the effects of nitrogen fertilization on grain yield, bran/rice ratio and the quality of bran, such as lipid and γ-oryzanol content. Methods: The experiment was conducted during 2021-2022 inside a net house. The experiment was arranged in a completely randomized design (RCD) with five replications for three nitrogen levels and two rice varieties. The rice grains from each cluster were milled to collect bran samples for yield, embryo, aleurone, lipid and g-oryzanol content analysis. Result: The rice bran ratio and quality (lipid and γ-oryzanol content) of the Ja35 variety were higher than those of the Ja23 variety at all fertilizer levels. Increasing the nitrogen fertilizer did not increase the rice bran ratio but improved the quality of the rice bran. Therefore, increasing the nitrogen fertilizer level is necessary to increase the rice bran ratio and quality of the rice bran for rice varieties with larger aleurone.