國產良質米全穀營養與 升糖指數研析

Abstract

稻米的營養價值高，特別在於米糠層含有豐富植化素，可以米糠醇(γ-oryzanol)與生育醇(tocopherol)、三烯生育醇(tocotrienols)作為代表性成分。全榖米飯即是糙米擁有優質營養，其礦物質與膳食纖維含量豐富，值得特別推廣。臺灣過去育種專家進行大量的秈稻與稉稻雜交育種，並且以米飯口感作為主要選拔標準，發展創造許多特色米種，即是今日的良質米品種。分析13個良質米品種糙米與白米的評估升糖指數(estimated glycemic index, EGI)，顯示臺中秈10號糙米與白米(人體試驗均屬於低GI食物)之EGI最低，兩者分別落於低GI與中GI區間，所有試驗品種的糙米平均EGI值均屬於低GI區間。 Rice grain is a nutritious food source, especially its bran layer. It possesses abundant phytochemicals, such as -oryzanol, tocopherols and tocotrienols. The rice whole grain, namely brown rice, is rich in minerals and dietary fiber, which is worth recommending for daily diet. In the past, in Taiwan, there were many breeders working on rice breeding by interspecific hybridization with varieties of Indica and Japonica. One of the key breeding criteria was the sensory evaluation of the cooked rice. Nowadays many brand-new cultivars produced have become representatives of High-Quality Rice in Taiwan. Among them, 13 cultivars of brown and white rice samples were employed for the analysis of estimated glycemic index. Results showed that the brown and white rice of the TCS10 rice cultivar (both belonged to the low GI level in the human study) were low and medium GI food, respectively. All brown rice samples of the thirteen cultivars were evaluated as low GI rating.