Sunflower (Helianthus annuus L.) is one of the most important oil crops in the world due to its excellent oil quality. This research was conducted to evaluate changes in the contents of oil, fatty acids and total tocopherol of sunflower seeds obtained from different maturity stages and positions on the head. The heads were harvested sequentially 10, 15, 20, 25, 30, 35, 40, and 45 days after flowering (DAF) in 2002 and 2003. The oil content of sunflower seeds increased significantly with seed development, reaching a maximum value of 45.8% at 35 DAF in 2002 and 47.9% at 30 DAF in 2003, after which it started to decline gradually up to 45 DAF. With regard to fatty acid composition, the general trend for linoleic acid was the opposite of that for oleic acid. Oleic acid decreased significantly, while linoleic acid increased significantly during the seed maturity process in both years. Palmitic and stearic acids showed different accumulation patterns depending on the year. In changes in total tocopherol a gradual decrease was detected from 10 to 35 DAF, after which a gradual increase was determined. The position of the seeds on the head had little effect on the oil content, but had a strong effect on the fatty acid contents. Linoleic acid decreased and oleic acid increased linearly from the side to the center seeds. The highest total tocopherol content was found in the side seeds of the head.

Sunflower (Helianthus annuus L.) is one of the most important oil crops in the world due to its excellent oil quality. This research was conducted to evaluate changes in the contents of oil, fatty acids and total tocopherol of sunflower seeds obtained from different maturity stages and positions on the head. The heads were harvested sequentially 10, 15, 20, 25, 30, 35, 40, and 45 days after flowering (DAF) in 2002 and 2003. The oil content of sunflower seeds increased significantly with seed development, reaching a maximum value of 45.8% at 35 DAF in 2002 and 47.9% at 30 DAF in 2003, after which it started to decline gradually up to 45 DAF. With regard to fatty acid composition, the general trend for linoleic acid was the opposite of that for oleic acid. Oleic acid decreased significantly, while linoleic acid increased significantly during the seed maturity process in both years. Palmitic and stearic acids showed different accumulation patterns depending on the year. In changes in total tocopherol a gradual decrease was detected from 10 to 35 DAF, after which a gradual increase was determined. The position of the seeds on the head had little effect on the oil content, but had a strong effect on the fatty acid contents. Linoleic acid decreased and oleic acid increased linearly from the side to the center seeds. The highest total tocopherol content was found in the side seeds of the head.