2.10. Measurement of the effect of extracts on oil oxidation in Oxipres
apparatus
The samples were prepared by mixing sunflower oil with 0.05%,
0.1% and 0.2% of extracts. Five grams of oil were placed in a reactor
tube and thermostated at 110C under oxygen atmosphere (5 bars)
in Oxipres apparatus (Mikrolab, Aarhus, Denmark). Pressure
changes which occur due to the absorption of oxygen consumed
for oil oxidation were recorded. The protection factor (PF) value
of sunflower oil in case of using plants extracts and their antioxidant activity (AA) were calculated by the following formulas:
PF = IPX/IPK; AA = (IPXIPK)/(IPBHTIPK), where IPX is induction
period of sample with additive (h); IPKis induction period of sample
without additive (h); IPBHTis induction period of sample with synthetic antioxidant BHT (h).