Effect of natural polyphenol on the oxidative stability of pecan oil.

We evaluated the antioxidant activity of natural polyphenols which gives high oxidative stability to the pecan oil. The in vitro DPPH radical scavenging, reducing power and total antioxidant activity of tested antioxidants demonstrated that tannic acid displayed the highest DPPH scavenging activity and provided the largest reducing power. During storage of pecan oil, based on oxidative stability tests, we further evaluated the protective effect of polyphenols and synthetic antioxidants on the oxidative stability of pecan oil. The results showed that caffeic acid inhibited oxidation of pecan oil effectively. Sesamol and catechin showed slight improvement in oxidative stability, while ferulic acid, erucic acid and rutin had no effect. Taken together, compared with synthetic antioxidants (TBHQ, BHT, BHA), caffeic acid was observed to be stronger than BHT and BHA and was close to TBHQ.