Changes in the Compositions of Fatty Acids and Tocopherols of Cotton Seeds during Maturation

Abstract

Five cultivars of cotton from harvests in USSR, USA, Thailand, Benin and Japan were grown in Japan (the University field). These cotton seeds obtained by cultivation were called samples I, II, III, IV and V, respectively. The cotton seeds were harvested at eight stages of development from 3 to 80 days after flowering, and the changes in lipid contents and fatty acid and the tocopherol (Toc) compositions were investigated. The Toc contents were determined by high-performance liquid chromatography with a spectrophotometric detector at 295 nm. The weights of the seeds rapidly increased until 30 days after flowering, and the seed weights of samples I, II, III, IV and V were 238, 195, 208, 163 and 167mg/seed, respectively, at 50 days after flowering. These seeds matured 70 days after flowering. Lipids accumulated at a steady rate up to 30 days after flowering, and the lipid contents of the mature seeds of samples I, II, III, IV and V were 28.2, 29.1, 26.4, 27.7 and 24.0mg/seed, respectively. Generally, the amounts of linoleic, palmitic and oleic acids increased with seed maturation, and the amounts of linolenic and cyclic fatty acids decreased. In the developing seeds of these cotton cultivars, the total Toe contents rapidly increased with increasing amounts of unsaturated fatty acids and their esters.