(Natural News) The antioxidant properties of bakery products can be increased by adding unrefined pumpkin seed oil, according to a study published in the journal Agronomy Research. The researchers from St. Petersburg Polytechnic University of Peter the Great examined the fatty acid compositions and biologically active components found in vegetable oils such as unrefined rice bran oil, unrefined pumpkin seed oil, and refined and deodorized sunflower oil. They assessed the antioxidant properties of the vegetable oils according to the different factors, such as the formation of the primary and secondary oxidation products; and the oxidation coefficient, which can be identified in the process of applying thermal treatment, resulting in vitamin E being destroyed. However, the resistance to the thermal oxidation process of the vegetable oils were affected due to their biochemical composition. The bakery products used in the study were made from wheat flour dough and were added with four percent of the corresponding vegetable oil and five percent sugar. The products were baked at two temperatures – at 200 C and at 220 C. The researchers looked at the antioxidant activity of the baked goods through chemiluminescence and through DPPH radical assay.
The findings of the study revealed that the vegetable oils increased the antioxidant activity in bakery products. The greatest increase in antioxidant activity was observed in baked goods added with pumpkin seed oil, followed by those with rice bran oil, and those with sunflower oil. In addition, the researchers observed that the total antioxidant activity was higher in the crumbs compared to the crust. Furthermore, the antioxidant activity increased as the baking temperature decreased. This effect was also observed in the antioxidant activity of aqueous extracts of crust and crumb in products with rice bran oil and sunflower oil as determined through chemiluminescence. On the other hand, the antioxidant activity of aqueous extracts in baked goods with pumpkin seed oil was found to be higher in the crust than in the crumb.