Cereal Chem 42:498 - 504.  |  VIEW ARTICLE

The Effect of Storage Time on the Compositional Patterns of Rice Fatty Acids.

T.-C Lee, W. T. Wu, and V. R. Williams. Copyright 1965 by the American Association of Cereal Chemists, Inc. 

As part of a study on the aging of rice, an investigation has been made of the effect of storage at room temperature on the compositional patterns of rice fatty acids. One large sample of freshly harvested Belle Patna rice was used for the entire experiment and was sampled every 2 weeks for a period of 6 months. The rice was shelled, milled, and ground to 20-mesh on the day of sampling and was immediately extracted with chloroform:methanol. The lipid extract was separated into four fractions by silicic acid chromatography. Three of these fractions were methylated by transesterification, and the resultant methyl ester mixtures analyzed by gas chromatography. Significant variation occurred from one sampling period to the next, but significant correlation between percentage composition and time was found in only two cases: the oleic acid and the linoleic acid of the phospholipid fraction. The oleic acid increased and the linoleic acid decreased with storage time. The same trend was observed in the fraction containing free fatty acids and mono- and diglycerides, although the correlation coefficients were slightly below that corresponding to the 5% probability level.