Tocopherol oil concentration in field-grown sunflower is accounted for by oil weight per seed

Tocopherols are natural antioxidants that increase the stability of fat-containing foods and perform important biological activities. Significant variations (389 to 1873 μg g oil-1) in the total tocopherol concentration of sunflower seed oil have been reported. The main objectives of this work were to determine the influence of intercepted photosynthetically active radiation on tocopherol concentration during seed filling and to establish and validate relationships between tocopherol concentration in oil and other quality variables of the seed. Seven sunflower hybrids were grown under good water and nutritional conditions in two similar experiments carried out in two contrasting environments. Treatments were applied to modify the amount of radiation intercepted per plant during seed filling in order to obtain a range in oil yield per plant and its components. Greater per plant intercepted radiation decreased the tocopherol concentration in oil. Tocopherol concentration decreased when oil weight per seed increased. Tocopherol concentration stabilized for oil weight per seed higher than 23 mg oil seed -1. This exponential relationship accounted for 73% of the variability in tocopherol concentration (507 to 1203 μg g oil-1) despite differences in hull type, locations, hybrids, and radiation treatments. The proposed relationship acceptably predicted independent results. Crop management techniques could lead to seeds with greater concentrations of tocopherols.Fil: Nolasco, Susana Maria. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ingeniería Olavarría. Departamento de Ingeniería Química; ArgentinaFil: Aguirrezábal, Luis Adolfo Nazareno. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Crapiste, Guillermo Hector. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentin