ひまわりの成熟過程における種子の脂質, 脂肪酸, トコフュロール及びステロール量並びに組成の変化について
1983 年 32 巻 3 号 p. 170-174
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1983 年 32 巻 3 号 p. 170-174
Compositional and quantitative changes of fatty acids, tocopherols, and sterols in lipids of sunflower seeds harvested at 5 to 80d after flowering were investigated. The fatty acid and tocopherol compositions of lipids were determined by GLC and HPLC. Sterol compositions in unsaponif iable matter separated by using preparative thin layer chromatography were determined by GLC with cholesterol as an internal standard.
The weights of the sunflower seeds increased rapidly during 35d after flowering, and the lipids accumulated at a steady rate up to 16d after flowering. The highest concentration of unsaponifiable matter and 4-desmethylsterol in lipids were found at an early stage after flowering, but the contents then decreased steadily. The percentages of campesterol, stigmasterol and β-sitosterol were 10.3, 23.9, and 65.7, respectively, in immature seed lipids (8d after flowering). But the percentages of campesterol and stigmasterol decreased markedly, whereas β-sitosterol increased up to maturity. The main tocopherol in seed lipids were α-and γ-tocopherol showed marked increase up to maturity, whereas γ-tocopherol contents in lipids were almost constant during maturation of seed. Generally, the percentage of linoleic acid in total lipids increased up to maturity, but the percentages of palmitic and linolenic acids decreased. The percentage of oleic acid in lipids reached a maximum at 16d after flowering, and decreased ever since. In the developing seeds of sunflower cultivars, the total tocopherol contents rapidly increased with increasing amounts of unsaturated fatty acids and their esters.
