米糠為碾米過程低價值之副產物。米糠曾被用做飼料之添加物。在某些國家，由米糠中萃取米糠油，去脂米糠成為残餘物。去脂米糠仍然含有多種具生物活性之營養成份。這些營養成份包括蛋白質、酚化合物及澱粉。從去脂米糠中分離這些營養成份後有利於其在醫療及食品工業之應用。
本研究利用兩種方法從去脂米糠中分離蛋白質、酚化合物及澱粉。在第一種方法中使用30oC水、0.1M NaOH溶液及80%乙醇溶液為溶劑。將澱粉分離出後分析其性質。以水萃取蛋白質後，利用海藻酸鈉及角藻膠將之從溶液中沉澱出來。最後分析液體部分所含之酚化合物以決定其產率。澱粉之產率約為84%而蛋白質及酚化合物之產率則比文獻報告為低。
第二種方法利用次臨界水從米糠中萃取蛋白質及酚化合物。將去脂米糠與水混合後加熱至125-200oC並加壓使水維持在液態。在米糠中萃出物中發現具有抗氧化性質，因此本研究進一步將萃出物分離出具抗氧化性之酚化合物及生肽。

In this study, extraction of protein, phenolic acids and starch from defatted rice bran was done by two methods. The first extraction procedure involved the use of water at 30oC, 0.1M NaOH solution and 80% ethanol solution as extraction solvents. Rice bran starch was separated and then analyzed for its properties. Rice bran protein extracted with water was then further precipitated out from the solution using alginate and carrageenan. Maximum amount of protein was recovered from the rice bran extract at pH 3.5 and 2:1 carrageenan-to-protein ratio for carrageenan and at pH 3.5 and 1:1 alginate-to-protein ratio for alginate with percentages of protein precipitated of 95 and 93, respectively. The extraction yield for extracted starch is about 83% while for protein and phenolic acids are lower than the reported yields of previous studies.
The second method employed subcritical water treatment for the extraction of protein and phenolic acids. Defatted rice bran mixed with water was heated at 125-200oC at high pressure to keep the water in liquid state. Maximum extraction yield of about 70% at 175oC was obtained from subcritical treatment. At this temperature, the amount of protein and phenolic acids detected in the subcritical extract is about 150 mg protein/g bran and about 2 mg phenolic acids/g bran. Other unknown compounds are still found in the subcritical extract and it is suggested that fractionation and identification of all the components in the complex DRB subcritical extract be done so that the subcritical extract maybe recommended for various applications.

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