Concentrations of Chlorogenic Acid, Oil, and Fatty Acids in Developing Sunflower Seeds 1

The concentrations of chlorogenic acid, oil, and fatty acids were determined during the development and maturation of sunflower seeds ( Helianthus annuus L.). When the cultivars ‘Krasnodarets’ and ‘Peredovik’ were sampled at 4‐day intervals from 5 to 29 days after flowering (DAF), the average chlorogenic acid concentration of hull‐free sunflower meal declined from an initial value of 0.40% to 0.18% at 9 DAF, then steadily increased to 1.96% by 29 DAF. This latter value represented three.quarters of the total chlorogenic acid deposited. The change in oil and chlorogenic acid concentrations followed relatively similar patterns (r = 0.93, at the 0.01 level, 25 dr). However, oil content did not decline during the first week and the period of most rapid increase in oil content occurred about 5 to 7 days before that of chlorogenic acid. The proportion of paimitic acid in the total fatty acids declined from an average of 26% at 5 DAF to 6.5% at 29 DAF, whereas linoleic acid declined from 49.6% at 5 DAF to 38.4% at 13 DAF then steadily increased to 67.0% at 29 DAF. This pattern was partially due to the presence of up to 12% linolenic, arachidic and behenie acids in imma. ture seeds, followed by their virtual disappearance by 17 DAF. Additional sampling between 21 and 49 DAF confirmed that most of the chlorogenic acid in sunflower seeds is synthesized between 13 and 35 DAF with the highest rate occurring between 21 and 28 DAF. Because maximum seed weight, oil content, and chlorogenic acid concentration coincide, it would not be practical to reduce chlorogenic acid levels in seeds by early harvesting.