Eff ect of microwave heating on oxidative stability of sunfl ower oil

Mikrovalno zagrijavanje moderna je i široko primjenjivana metoda za pripremanje hrane. U ovom radu istraživan je utjecaj mikrovalnog zagrijavanja na oksidacijsku stabilnost hladno prešanog suncokretovog ulja, visokooleinskog suncokretovog ulja te njihovih smjesa. Biljna ulja zagrijavana su u mikrovalnoj pećnici kod različite snage u vremenu od 5 minuta. Također, uzorci su zagrijavani u mikrovalnoj pećnici kod snage 300 W u različitim vremenima trajanja. Rezultati testa prikazani su kao vrijednost peroksidnog broja tijekom mikrovalnog zagrijavanja. Visokooleinsko suncokretovo ulje ima bolju stabilnost prema oksidaciji upravo zbog visokog udjela oleinske kiseline. Dodatkom visokooleinskog suncokretovog ulja u hladno prešano ulje dolazi do promjene oksidacijske stabilnosti smjese ulja. Primjenom veće snage i vremena trajanja mikrovalnog zagrijavanja dolazi do većeg oksidacijskog kvarenja ispitivanih ulja.Microwave heating is a modern and widely used method for food preparation. This study researched the effects of microwave heating on the oxidative stability of cold pressed sunflower oil, high oleic sunflower oil and their blends. Vegetable oils were heated in a microwave oven at different power levels for five minutes. Also, the samples were heated in a microwave oven at 300 W of power at different times. The results of test are presented as the value of peroxide number during microwave heating. High oleic sunflower oil has a better stability to oxidation because of the high content of oleic acid. The adding of high-oleic sunflower oil in cold pressed oil results in the change of oxidation stability of oil mixtures. By applying higher power and time of microwave heating results in a greater oxidative deterioration of test oil