The influence of microwave heating and antioxidants addition on oxidation stability of pistachio oil

Mikrovalno zagrijavanje je moderna i široko primjenjivana metoda za pripremanje hrane. U ovom radu je istraživan utjecaj mikrovalnog zagrijavanja na oksidacijsku stabilnost hladno prešanog ulja pistacije, sa i bez dodatka antioksidanasa i sinergista. Uzorci ulja su zagrijavani u mikrovalnoj pećnici kod različite snage uređaja u vremenu 5 minuta. Također, uzorci su zagrijavani u mikrovalnoj pećnici kod konstantne snage 300 W u različitom vremenskom periodu. Rezultati testa prikazani su vrijednostima peroksidnog broja nakon mikrovalnog zagrijavanja. Primjenom veće snage uređaja i duljeg vremena trajanja mikrovalnog zagrijavanja dolazi do povećanja oksidacijskog kvarenja ispitivanog ulja. Dodatkom antioksidanasa i sinergista postignuta je veća otpornost ulja prema oksidaciji. Nakon 25 minuta mikrovalnog zagrijavanja dobivene su niže vrijednosti peroksidnog broja u odnosu na uzorak ulja bez dodanog antioksidansa (kontrolni uzorak). Najbolju otpornost prema oksidacijskom kvarenju pokazao je dodatak eteričnog ulja rtanjskog čaja, u odnosu na dodatak drugih ispitivanih antioksidanasa.Microwave heating is a contemporary and widely applied method of food preparation. This essay discusses the influence of microwave heating on the oxidation of cold-pressed pistachio oil with and without the addition of antioxidants and synergists. Oils samples with and without the addition of antioxidants and synergists were heated in a microwave oven using different power settings at 5 minute intervals. Samples were also heated in microwave oven using constant power settings of 300 W at different time intervals. The test results are shown through peroxide value and measured after microwave heating. Higher power settings and prolonged microwave heating are causing more massive oxidative damage of the tested oil. The addition of antioxidants and synergists achieved greater resistance to oil oxidation. Microwave heating with duration of 25 minutes resulted with lower peroxide value comparing to the oil sample without added antioxidant (control sample). Best resistance to oxidation deterioration showed the addition of essential oil of winter savory, comparing to the addition of other antioxidants that were examined