Oxidative stability of cottonseed oil enriched with Cameroonian plant leaves extracts

Abstract

This work aimed to assess the oxidative stability of cottonseed oil enriched with natural antioxidants from Cameroonian plant leaves extracts. Total polyphenols, flavonoids, and antioxidant activity via DPPH radical scavenging assay were assessed in ethanolic extracts. These extracts were added to cottonseed oil at concentrations of 200, 500, 1250, and 2000 ppm. The cottonseeds’ oil oxidative stability was evaluated by determining their induction/stability times on Rancimat (120±1.6°C) and by measuring their oxidative state in Schaal oven during 30 days (samples were removed after 10 days) of storage at 60°C. The outcomes showed that Canarium schweinfurthii, Trichoscypha acuminate, Dacryodes edulis, and Psidium guajava leaves extracts are rich in polyphenols (18.56 to 42.70 mg/g) and flavonoids (2.14 to 5.36 mg/g). The ethanolic extracts, above 1250 ppm, were also efficient like synthetic antioxidants in inhibiting the oxidation of cottonseeds oil at high temperatures. The evaluation of oxidation parameters of enriched cottonseeds oil showed that different extracts at 2000 ppm can limit the appearance of both primary and secondary oxidation products in oils.