Investigation of the antioxidant effect of nano encapsulated rosemary leaf extract in basil (Ocimum basilicum) seed gum on oxidative stability of sunflower oil and sensory properties of fried potato strips

In this study, the antioxidant properties of nanoencapsulated rosemary leave extract in biopolymer basil (Ocimum basilicum) seed gum coating to control the oxidative stability of sunflower oil and sensorial properties of fried potato strips were studied. The rosemary leaves extract obtained by ultrasonic bath has phenolic compounds (174.4 ± 25.9 mg gallic acid / g extract) and flavonoid (78.30 ± 3.2 mg rutin / g extract). Antioxidant activity of DPPH free radical scavenging by IC50 was 98.16 ppm and oxidative stability at 200 ppm was 5.08 h. The average size of nanoparticles in basil seed gum coating was 284.2 nm. The peroxide value and thiobarbituric acid value of oil samples were calculated every 4 days (0, 4, 8, 12, 16, 20, and 24 days). The results showed that oil oxidation in samples containing nanoencapsulated rosemary extract was less than the control sample, oil containing free extract or TBHQ. At the end of 24 days of incubation period, the peroxide value of oil samples containing synthetic antioxidant TBHQ and oil samples containing nanoencapsulated rosemary extract in the basil seed gum were 23.4 and 17.80 mEq O2/ kg oil and thiobarbituric acid value were 0.16 and 0.06 mg of malondialdehyde/kg oil respectively. In addition, the higher sensorial score of color, odor, taste and overall acceptance was related to potato strips fried in oil containing nanoencapsulated rosemary extract. The results of this study suggest the use of nanoencapsulated rosemary extract in basil seed gum coating to increase shelf life of sunflower oil.