Characterization of Free and Bound Lipids among Four Corn Genotypes as Affected by Drying and Storage Temperatures

For whole grains, the most sensitive components to the environmental changes are the lipids. In the current study, the effects of drying temperature (27 and 93 °C) and storage temperature (4 and 27 °C) on the fatty acid (FA) levels and lipid classes of endosperm lipids on four selected corn genotypes were investigated during a 12-month storage period. Storage temperature indicated greater impact on the FA composition than did the drying temperature. The ratio of saturated to unsaturated fatty acids, which was around 0.20–0.22 levels in the free lipid (FL) fractions of all corn types studied here, did not change significantly due to the drying and storage temperatures. However, in the bound lipid (BL) fractions, it was changed by a change in the drying and storage temperature in some of the corn types. Some changes were also found in the lipid classes within the FL and BL fractions of the studied corn samples. No lysophosphatidylcholine (LPC) was found in the FL fractions. In the BL fractions of two of the corn samples, the level of free fatty acids (FFA) increased more likely due to the deterioration of LPC. The results of the current study indicated a possible migration of triglycerides and FFA between the FL and BL fractions due to drying and storage at higher temperatures.