Impact of Moringa oleifera leaves extract in the stabilization of margarine under accelerated storage

Margarine, an emulsion constituted mainly of fat up to 90%, is used for highly variable cooking purposes. The susceptibility of lipids to oxidation needs processing operations/strategies that increase their shelf life and resistance to high temperatures such as the addition of synthetic antioxidants. Due to the toxicity of these later, the demand and search for natural antioxidants are continuously increasing by consumers and industrials. In this study, the antioxidant potential of Moringa oleifera leaves extract (MOLE), obtained from dry leaves with 80% methanol, for stabilization of margarine was evaluated under accelerated storage (30 days at 65 degrees C). MOLE was added to margarine at 100, 400, 600, and 800 mg/kg and compared with the control (no MOLE or additive) and reference margarine supplemented with a standard synthetic antioxidant (100 mg/kg of tocopheryl acetate). The progression of oxidation was monitored by analyzing the formation of primary and secondary lipid oxidation compounds as well as fatty acid, tocopherol, tocotrienol, and sterol profiles. The results revealed that 600 and 800 mg/kg MOLE were endowed with the highest antioxidant properties during accelerated storage of margarine. MOLE effectively reduced the peroxide and p-anisidine values as well as the induction time by Rancimat, even at 100 mg/kg. Color changes and degradation of fatty acids, especially linoleic acid (C18:2), were also statistically reduced. Interestingly, MOLE also exhibited a strong ability to protect endogenous alpha-tocopherol against oxidative degradation. It revealed also that MOLE expressed an effective antioxidant effect and increased the thermal stability of margarine under hot storage. Thus, the application of MOLE as a natural antioxidant can be of particular interest in lipid based agro-food industries.