쌀의 油脂成分이 酸化過程에 미치는 영향 = Effects of the Oxidative Changes in the Rice Lipids Fractions

국문 초록 (Abstract)

Hexane과 ethanol을 利用하여 米粒에서 油出한 쌀 油脂를 Folch's method에 依해 精製하고, 이들을 紫外線 照射 또는 40˚C 暗祈에 저장하여 쌀 抽脂의 酸化樣相을 살펴 본바, 다음과 같은 結論을 얻을 수 있었다.
1. 酸素吸收에 依한 重量增加現象은 紫外線 照射에 의하여 3日以內에 뚜렷한 重量增加 (0.6-0.8 以上)을 보였으나, 40˚C 暗所에서는 45日 以後에 비로서 현저한 重量增加의 商을 볼 수 있었다. 各處理別 誘導期間은 hexane 抽出油脂가 紫外線照射에서는 1日, 40 辯所에서는 30脚이있고, ethanol摘出油指는 紫外練照財예서는 25, 40˚C 暗所에서는 40日 이었으며, hexane抽出油脂가 ethanol抽出油脂보다 그 安定性이 多少 낮은 것으로 나타났다. 또한 各處理別 變敗臭는 誘導期間보다 약간늦게 볼 수 있었다.
2. 各處理別로 總 Carbonyl 化合物 및 malonaldehycle(M. A)의 변화를 살펴 본 바, 紫外線 照射지역에서는 Carbonyl價가 2-4 日째 M.A.는 7日頃에 그 生成量이 各各 頂點을 형성하다가 천천히 減少되었고, 40˚C 暗所에서는 Carbonyl價 및 M.A. 生成量 共히 55日까지 徐徐히 增加하였다.
3. 全般的으로 hexane抽出油脂가 ethanol抽出油脂보다 酸化反應이 더 빨랐으며 이는 脂肪酸組成 및 未確認된 抗酸化物質의 存在에 依한 可能性으로 생각된다. 그리고 紫外線 照射는 기지의 油脂의 酸化를 급격히 促進시킨다.
4. Hexane에 依해 抽出된 쌀油脂를 油出直後와 40˚C 55日間 저장처리한 후의 脂肪酸組成을 살펴 본 바 linoleic 및 linolenic acid가 뚜렷이 감소함을 볼 수 있고, 相對的으로 Oleic, Stearic, Palmitic acid 等이 증가하였다.

다국어 초록 (Multilingual Abstract)

Oxidative changes in the rice lipids under accelerated condition were studied by measurine the changes in weight gain, total carbonyl compound, malonaldehyde, and fatty acid composition. Rice lipids were prepared by extraction with either n-hexane or ethanol from polished rice grain and purified by Folch's method. The lipid preparations were either incubated in dark at 40˚C or irradiated with ultra-violet light for a period of 60 days.
Weight gain by oxygen absorbed sharply increased within 3 days in the rice lipids under UV light irradiation. However, with the rice lipids at 40˚C incubation a moderate incrcase in weight was observed only after 45 days storage. Their induction periods were one day(hexane extracted, under UV light), 2 days(ethanol extracted, under UV light), 30days (hexane extracted, at 40˚C), and 40 days (ethanol extracted, at 40˚C) respectively. Oxidative rancid odor appeared at the end of the induction period. Total carbonyl compound and malonaldehyde markedly increased within 7 days, and decreased in the rice lipids under ultra violet light irradiation, while at 40˚C incubation they were continued to increase slowly throughout the storage. The hexane extracted lpid were less stable than ethanol extracted lipid on the basis of oxygen absorption, malonaldehyde and other carbonyl compound for-mation.
With the hexane extracted lipid during 55days incubation at 40˚C, the contents of linoleic and linolenic acids decreased, while the oleic, Palmitic and stearic acids increased.

목차 (Table of Contents)

• I. 서론
• II. 실험방법
• 1. 실험재료
• 2. 실험방법
• III. 결과 및 고찰
• 1. 吸收된 酸素에 依한 油脂試料의 重量增加
• 2. 總 Carbonyl 化合物 및 Malonaldehyde(M.A.)의 변화
• 3. 脂訪酸組成의 變化
• IV. 요약