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This study is concerned with the effect of the process of roasting of naked pumpkin seeds prior to their pressing on the chemical composition and oxidative stability of the extracted oil. Ground seeds were roasted at temperatures of 90, 110, and 130°C for 30 and 60 min, according to the traditional technology of production of roasted pumpkin oil. Depending on the roasting conditions of the seeds, this treatment resulted in a significant increase of the contents of phospholipids (from 0.005 to 0.463%), total phenolic compounds (from 4.63 to 19.60 mg/kg), and total tocopherols (from 265.79 to 350.98 mg/kg) in oil. Higher contents of these minor components enhanced the oxidative stability of the oil, i.e., increased the induction period (from 4.50 to 12.93 h). However, at the same time, the applied thermal treatment generated an increase in the primary and secondary oxidation products, resulting in higher Totox values that could lower the quality of the oil.

Summary The content of tocopherols, B vitamins, as well as free soluble, soluble conjugated and insoluble bound phenolic compounds was determined in untreated, steeped and sprouted wheat grains. Antioxidant capacity of whole wheat grains and their phenolic fractions was also evaluated. Sprouting significantly increased the levels of tocopherols, niacin, riboflavin, as well as free and bound phenolic compounds improving nutritional value and antioxidant capacity of wheat grains/flour. After sprouting for 5 days, the content of total phenolics, flavonoids and ferulic acid calculated as the sum of its fractions was increased by 9.9, 30.7 and 21.6%, respectively. The content of α‐, β+γ‐ and δ‐tocopherols was increased for 3.59‐fold, 2.33‐fold and 2.61‐fold respectively, while the content of niacin, as predominant B vitamin, was increased for 1.19‐fold after sprouting. The total antioxidant capacity of untreated, steeped and sprouted whole wheat grains was 19.44, 20.37 and 22.70 mmol Trolox Eq/kg, respectively. Sprouted wheat, as a rich source of bioavailable phytochemicals, should be used to improve the nutritional quality of food.

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