Influence of microwave heating and antioxidant parameters on the sustainability of Olive Oil variety Oblica

U ovom radu istraživan je utjecaj mikrovalnog zagrijavanja na oksidacijsku stabilnost ekstra djevičanskog maslinovog ulja, sa ili bez dodatka antioksidanasa i sinergista. Od prirodnih antioksidanasa korišteni su ekstrakt ružmarina i ekstrakt zelenog čaja te sinergist limunska kiselina. Uzorci ulja sa ili bez dodatka antioksidanasa i sinergista zagrijavani su u mikrovalnoj pećnici kod konstante snage 300 W u različitom vremenskom periodu (5, 10, 15 i 20 minuta). Uzorci su također zagrijavani i kod različite snage uređaja (180, 300, 450 W) u konstantnom vremenskom periodu 5 minuta. Rezultat testa ubrzane oksidacije maslinovog ulja izražen je peroksidnim brojem. Mikrovalnim zagrijavanjem uzoraka tijekom duljeg vremena zagrijavanja dolazi do porasta temperature i vrijednosti peroksidnog broja, odnosno dolazi do porasta oksidacijskog kvarenja ulja. Dodatkom antioksidanasa i sinergista povećana je stabilnost maslinovog ulja. Najveća stabilnost ekstra djevičanskog maslinovog ulja postignuta je kombinacijom ekstrakta zelenog čaja i sinergista limunske kiseline.This essay discusses the effect of microwave heating on the oxidative stability of extra virgin olive oil with or without the addition of antioxidants and synergists. Of natural antioxidants are used rosemary extract and green tea extract and citric acid synergist. Oil samples with or without the addition of antioxidants and synergists were heated in a microwave oven at a constant power of 300 W over a different time period (5, 10, 15 and 20 minutes). Samples were also heated at different power levels (180, 300, 450W) in a constant time period of 5 minutes. The result of the accelerated oxidation test of olive oil is expressed by the peroxide number. Microwave heating of the samples during a longer heating time increases the temperature and the value of the peroxide number, which results in an increase in oxidative oil degradation. Addition of antioxidants and synergists increased the stability of olive oil. The highest stability of extra virgin olive oil was achieved by a combination of green tea extract and synergistic citric acid