Trolox equivalent antioxidant capacity

Trolox Equivalent Antioxidant Capacity (TEAC) is a method used to measure the antioxidant capacity of various substances. It is named after Trolox, a water-soluble analogue of vitamin E, which serves as a reference standard in the TEAC assay.

Overview

The TEAC assay measures the antioxidant capacity of a substance by comparing its ability to scavenge the ABTS radical cation (ABTS•+) to that of Trolox. The ABTS•+ is a blue-green chromophore with maximum absorption at 734 nm, and its color fades as it is reduced by antioxidants. The degree of color fading is proportional to the antioxidant capacity of the substance being tested.

Methodology

The TEAC assay involves the generation of the ABTS•+ radical cation by the reaction of ABTS with potassium persulfate. This reaction produces a stable radical cation that is blue-green in color. The antioxidant substance is then added, and the decrease in absorbance at 734 nm is measured over a certain period of time. The antioxidant capacity of the substance is then calculated by comparing the decrease in absorbance to that of a Trolox standard.

Applications

The TEAC assay is widely used in food and health-related research to measure the antioxidant capacity of various substances, including fruits, vegetables, grains, spices, herbs, beverages, and dietary supplements. It is also used in the study of oxidative stress and free radicals in biological systems.

Limitations

While the TEAC assay is a useful tool for measuring antioxidant capacity, it has some limitations. For example, it does not provide information about the specific types of antioxidants present in a substance, nor does it indicate how these antioxidants may interact with each other. Furthermore, the TEAC assay measures antioxidant capacity in vitro, which may not accurately reflect the antioxidant activity in vivo.

See also

• Oxygen radical absorbance capacity
• Ferric reducing ability of plasma
• Total antioxidant capacity