Fatty Acid Composition of Three Rice Varieties Following Storage
Zhongkai Zhou, Chris Blanchard, Stuart Helliwell and Kevin Robards
Journal of Cereal Science Volume 37, Issue 3 , May 2003, Pages 327-335
2003
บทคัดย่อ
The petroleum ether extractable lipids (PEE-L) and aqueous propan-1-ol extractable lipids (PWE-L) of three varieties of rice were determined gravimetrically and characterised by fatty acid profiles. The content of PEE-L (22·5–28·2 mg g-1) was higher than that of PWE-L (7·4–11·5 mg g-1) in brown rice with the situation reversed in milled rice (3·0–4·5 mg g-1 vs. 7·2–8·7 mg g-1). The ratio of unsaturated fatty acid to saturated fatty acid was about two times higher in PEE-L than that in PWE-L for both brown and milled rice reflecting the selective complexation of saturated fatty acids. Rice storage at 37 °C resulted in some minor but statistically significant changes in the fatty acid profile. In the case of brown rice, the only notable changes were a reduction in the amounts of oleic and linoleic acids in the aqueous propan-1-ol extractable fatty acid fraction (PWE-FA) following storage at the higher temperature. Milled rice of all three varieties showed a decrease in linoleic acid content of PEE-L following storage at 37 °C for 4 and 7 months compared to storage at 4 °C. There was no change in fatty acid contents of PWE-L of milled rice when stored at 4 and 37 °C for 4 and 7 months. This implies that the PWE-L (or bound lipids) were more stable than PEE-L (or free lipids) during storage.