Extraction of high stearic high oleic sunflower oil (HSHO): Effect of dehulling and hydrothermal pretreatment

The effect of a hydrothermal pretreatment on the solvent extraction of oil and minor compounds (tocopherols) from high stearic high oleic sunflower seeds (HSHO), partially dehulled and undehulled, was analyzed. Samples of sunflower seeds of different origins and oil contents (high oil, 43.0% d.b., and low oil 35.1% d.b.) were used. The oil yield increased significantly due to the hydrothermal pretreatment (p <= 0.05) for HSHO samples with high oil content, both partially dehulled and undehulled. The pretreated HSHO samples with low oil content did not show significant differences in oil yield compared to the untreated samples. The effective diffusion coefficients for the hydrothermally pretreated seeds (2.12.10(-11) m(2) s(-1)) and the untreated samples (7.07.10(-12) m(2) s(-1)) were determined based on the oil extraction from the partially dehulled high oil HSHO samples. For both types of partially dehulled HSHO seeds, a significant increase in tocopherol content in the oils extracted from the pretreated samples was observed.