Impact of microwave heating and antioxidans on change of vegetable oil stability

U ovom radu istraživan je utjecaj dodatka prirodnih antioksidanasa ekstrakta ružmarina (Oxy’Less® Clear, Oxy’Less® CS ), ekstrakta zelenog čaja u udjelu 0,1 % i sintetskog antioksidansa oktil galata u udjelu 0,01 % na oksidacijsku stabilnost kikirikijevog ulja, suncokretovog ulja, repičinog ulja, ulja kukuruznih klica i lanenog ulja. Oksidacijska stabilnost ulja, sa i bez dodanog antioksidansa, ispitivana je primjenom mikrovalnog zagrijavanja. Rezultati utjecaja dodatka antioksidansa i vremena trajanja mikrovalnog zagrijavanja na promjenu oksidacijske stabilnosti biljnih ulja prikazani su peroksidnim brojem. Porastom vremena tretiranja biljnih ulja mikrovalnim zagrijavanjem kod konstantne snage 450 W smanjuje se održivost ili stabilnost ulja. Dodatkom ispitivanih prirodnih antioksidanasa i sintetskog antioksidansa u biljno ulje dolazi do porasta stabilnosti ulja prema oksidacijskom kvarenju, niže su vrijednosti Pbr nakon 25 minuta mikrovalnog zagrijavanja. Dodatak ekstrakta ružmarina Oxy’Less® CS (0,1 %) značajno povećava stabilnost ispitivanih ulja u odnosu na dodatak oktil galata, ekstrakta zelenog čaja i ekstrakta ružmarina Oxy’Less® Clear.This study researched the effect of added natural antioxidants of rosemary extract (Oxy’Less® Clear, Oxy’Less® CS), green tea extract in dosage of 0.1% and the octyl gallate synthetic antioxidants in dosage of 0.01% on the oxidative stability of peanut oil, sunflower oil, rapeseed oil, maize germ oil and linseed oil. The oxidative stability of the oils, with and without the added antioxidants, was evaluated using microwave heating. The effects of the added antioxidants and microwave heating times on the change in the oxidative stability of the vegetable oils are indicated by peroxide number. Raising the time of the microwave heating treatment for the plant oils at the constant power of 450W reduces the viability or stability of the oils. Adding the tested natural antioxidants and the synthetic antioxidant to the vegetable oils leads to an increase in oil stability towards oxidative deterioration, lowering the peroxide number values after 25 minutes of microwave heating. The addition of the Oxy’Less® CS rosemary extract (0.1%) significantly increases the stability of the tested oils compared to the addition of octyl gallate, green tea extract and the Oxy’Less® Clear rosemary extract