The effect of qadomeh shahri seed gum and whey protein isolate on the antioxidant properties of nanoencapsulated sage extract to increase the stability of sunflower oil

Sunflower oil is one of the most important vegetable oils with high nutritional value, which is unfortunately sensitive to oxidation due to unsaturated fatty acids. In this study, sage leaf extract was obtained using ultrasound bath and ethanol solvent: water (70:30) at 35 ° C for 30 min at 35 KHz. The total phenolic content of extract was 31.12 mg GA/g. Antioxidant activity of 50, 100, 200 and 250 ppm of sage extract was measured by beta-carotene/linoleic acid bleaching assay and oxidative stability index. The results showed that increasing in the concentration of extract increased the antioxidant activity and oxidative stability index. Sage extract (250 ppm) was used for encapsualtion in the wall of qadomehshahri seed gum/whey protein isolate at 1: 0, 1: 1 and 0: 1 ratio. The particle size of the nanocapsule varied between 217.4 and 0.270 nm, and the nanocapsule prepared withqodomehshahrihad the largest size and the nanocapsule prepared with composition of gum and protein isolate had the smallest size. In order to intensify the oxidation process, sunflower oil without antioxidants, oils containing free extracts and TBHQ was placed in an oven at 60 ° C for 24 days. Peroxide, para-anisidine and Totox value of the samples were measured. The results showed that oil oxidation in samples containing encapsulated extract was less than the control, and oil containing free extract and TBHQ. At the end of storage time, the peroxide and paraanisidine value in oil samples containing encapsulated extract was less than oil containing synthetic TBHQ antioxidant and free extract. Also, among the walls used for encapsulating of sage extract, a composite wall made of qodomehshahri seed gum and whey protein isolate is the best coating for encapsulation the extract to increase the shelf life of sunflower oil.