2014-09-092024-05-14https://scholars.lib.ntu.edu.tw/handle/123456789/660947摘要：稻米中的直鏈澱粉對於稻米的食用品質與加工特性影響十分顯著，因此，直鏈澱粉含量通常可作為稻米品質與加工性質最重要的評估指標。長久以來，雖然已有許多種方法可以用來測定穀粉及澱粉中之直鏈澱粉含量，而以碘呈色染色法最為普遍。但卻常常因為使用之方法、藥劑、標準品、反應溫度、作用時間，甚至是操作人員與環境之差別，而有相異的數值，造成檢測者、原料買賣雙方及使用者諸多的不便與煩惱。本計畫主要目的包括：(1)比較法定公告方法－－AACC method 61-03及ISO 6647-2之碘呈色比色法(iodine colorimetry)之測定結果，確立實際操作步驟，(2)建立以高效能分子篩層析法(high-performance size-exclusion chromatography, HPSEC)搭配酵素去分支試驗，以直接測定樣品中直鏈澱粉含量，並用以作為比色法之標準曲線制定用之標準品提供依據，及(3)以建立之上述兩種方法進行市售稻米及米榖粉樣品中直鏈澱粉含量分析。此計畫完成後，將建立一套適用於稻米、米榖粉及米澱粉中直鏈澱粉含量測定之常規比色測定法及標準品製備之液相層析分子篩測定法，提供農政單位及標準局參考。<br> Abstract: Amylose in rice has significant effect on its eating quality and processing functionality. Thus, the amylose content of rice is a very important index to evaluate the rice and its processing properties. There are many methods to determine the amylose content (AC) in rice and its derivates. However, different values are always obtained due to the different methods used which are determined based on different principles. Iodine coloremetry is the most popular method to determine the amylose content in cereals. The reagents, standards, pH, temperature, time, even operator and environmental coditions were reported to cause the deviations of results. The inconsistency in the AC causes unnecessary arguments among the testers, the merchants and users. The objectives of this project include (1) to compare the results obtained by AACC method 61-03 and ISO 6647-2 for amylose contents in kwnon variety and cultiva rice samples, which will be used to establish the details procedures to perform the routine emthod accurately; (2) to establish the method for directly determining the amylose content in rice standards by combining enzymatic debranhing and using high performance size exclusion chromatography (HPSEC), and (3) to assay the amylose contents in rice, rice flour and rice starch collected from local markets by using the established routine method (iodine colormetry) with the rice flour standards with the known amylose conten which are certified by established SEC-debranching method. The achievemetns of this project will provide a routine method for amylose content determination of rice and rice flour and a SEC method for rice flour standards with the certified amylose content for preparing a standard curve for the routine method.稻米碘呈色比色法直鏈澱粉含量分子篩層析法riceidine colormetryamylose contentSize exclusion chromatography