Antioxidative Functionality of Natural Olive Extract vs. Synthetic Tertiary Butyl Hydroquinone in Sunflower Oil During Deep Frying

Abstract

Refined, bleached and deodorized (RBD) sunflower oil (SFO) supplemented with (i) 100ppm and (ii) 200ppm olive extract (OE), (iii) 200ppm tertiary butyl hydroquinone (TBHQ), (iv) combination of 100ppm OE and 100ppm natural tocopherol (TOCOL), as well as (v) antioxidant (AOX) free SFO were used for deep frying experiments. Experimental design implied 6 consecutive potato chips’ deep frying cycles for 5 consecutive days. SFO samples were analyzed for the content of total polar compounds (TPC) and free fatty acids (FFA), as well as p-anisidine values (AV) and red/yellow (R/Y) color values. Results showed that the addition of AOX to SFO reduce both hydrolytic and oxidative changes in the frying media. TPC content in SFO with 100 ppm OE was similar to that in SFO with 200ppm TBHQ, and it was 2.8 times lower than TPC content in SFO without AOX after 5 days of deep frying. Enhancement of OE level to 200ppm, as well as the use of OE/TOCOL combination did not show any improvement in the suppression of TPC formation. The AV values of SFO with 100 ppm OE and SFO with 200ppm TBHQ were nearly identical and comparable with those in the presence of 200ppm OE and 100ppm OE plus 100ppm TOCOL. AV of SFO without added AOX was 77% higher than that of SFO with 100ppm OE. SFO with 100ppm and 200ppm OE exhibited reduced formation of FFA compared to SFO without AOX, SFO with TBHQ and SFO with combination of OE and TOCOL. No significant differences in R/Y color values of SFO with 100-200ppm OE, as well as with 200ppm TBHQ, were observed; however, color values of SFO without AOX were ca 2 times higher vs. SFO with added AOX.