Antioxidant Activity Evaluation of Tocored through Chemical Assays, Evaluation in Stripped Corn Oil, and CAA Assay

Abstract

γ‐Tocopherol‐5,6‐quinone (tocored) is a crucial oxidized product of γ‐tocopherol (γ‐T) found in edible oil. Previously published studies on antioxidant activity (AOA) of tocored are not consistent. This study aims to monitor its AOA comprehensively through chemical assays (1,1‐diphenyl‐2‐picrylhydrazyl [DPPH] and ferric reducing antioxidant power [FRAP]), antioxidant evaluation in a food model system (stripped corn oil), and cellular antioxidant activity (CAA) assay, which would reasonably widen the knowledge of the AOA of γ‐T and tocored. In both DPPH and FRAP assays, tocored shows less AOA than γ‐T. Results of chemical properties in the Schaal oven test show that tocored possesses better AOA than γ‐T. Correlation coefficients of γ‐T and tocored between peroxide and K234 or p‐AnV are 0.8784–0.9875 and 0.8716–0.9879, respectively. The CAA assay also shows that tocored possesses better cellar AOA than γ‐T, with an EC50 at 21.55 µg mL−1. Drawing conclusions from the results from chemical assays, evaluation in stripped corn oil, and CAA assay, tocored is verified as a potent antioxidant in edible vegetable oils compared to γ‐T. Practical Applications: The present work widens the knowledge of antioxidant activity of tocored and gamma‐tocopherol, and contributes to the understanding of existing antioxidant activity when gamma tocopherol is depleted when edible oils are in storage and processing processes.

Restoration of Germinal Epithelium with Usage of Antioxidant Oils in Phenytoin Induced Testicular Toxicity: A Comparative Study in Rats

“…The need for antioxidant agents that can reduce the free radical levels in various parts of the body is absolutely crucial and this effect can be seen in some oils. Corn Oil has been concluded to be a potent antioxidant agent from results of chemical assays 12 . Another study on the body weight, biochemical, and haematological parameters have also proved the capability of corn oil has on the liver and kidneys of rats, further highlighting its antioxidant prowess 13 .…”

Antioxidant interaction between α-tocopherol and γ-oryzanol in HepG2 cells

“…These findings aligns with Zheng's previous research, which also reported a positive correlation between CAA and concentration of single addition. 22 Interestingly, when the two were combined at a fixed ratio of 1 : 10 and tested at different concentrations, the CAA values exhibited a biphasic tendency. Initially, there was an increase in CAA values, followed by a subsequent decrease.…”

Color Reversion of Refined Vegetable Oils: A Review

“…In addition, at present, knowledge about the mechanism of color reversion is also limited due to the complex transformations of tocored in oil systems [ 35 ]. Tocored has been shown to have antioxidant activity [ 42 , 43 ], and it might be oxidized during the color reversion process [ 5 ]. Significantly, the effect of the oxidation products of tocored on color reversion should not be ignored, as the contribution of the oxidation products of tocored to color reversion is not yet fully understood.…”