New insights on phytocannabinoids role in antioxidant activity of hemp inflorescences extract in high-oleic sunflower oil

Hemp (Cannabis sativa L.) inflorescences contain bioactive compounds potentially able to counteract lipid oxidation in vegetable oils. In this study, two hemp inflorescences extracts with (E) and without (wE) phytocannabinoids were tested at 0.02, 1.0, and 2.0 g/100 g of high-oleic sunflower oil (HOSO) exposed to thermo-oxidative conditions (90 °C; pO2, 600 KPa). Immediately at the end of induction time, the oxidative stability index (OSI), peroxide value (PV), main lipid classes, phytosterols, phytosterols oxidation products (POPs) content, and volatile organic compounds were determined. E extract added at 2.0 g/100 g proved to be more effective than wE extract, extending the OSI by almost 30 % with respect to control. The lowest PV (p < 0.01) was observed in the oil containing E (2.0 g/100 g), which also proved to significantly reduce the POPs content (p < 0.05). Both extracts had no effect on lipolysis during the entire experiment. The principal component analysis highlighted different antioxidant activity related to both type of extract and their concentration. These results suggest that hemp inflorescences could be a source of natural preservatives for vegetable oils even under severe oxidative conditions and confirm that phytocannabinoids play a key role in the modulation of antioxidant activity.