Comparison of antioxidant capacity of 4-vinylguaiacol with catechin and ferulic acid in oil-in-water emulsion.

Abstract

The product of ferulic acid decarboxylation, 4-vinylguaiacol (4-VG), is an important antioxidant and is reported to have an antioxidant capacity comparable to α-tocopherol. In this study, evaluation on antioxidant capacities of ferulic acid, catechin, and 4-VG was performed when 200ppm of each compound was added in a 10% O/W emulsion for 50days. Peroxide value (POV) results of the O/W emulsion containing 4-VG were noteworthy. The POV was 1.9meq/L of emulsion after 29days, which was no different to the initial value (day 0). Even when the oxidation was allowed to advance to day 50, the POV remained at 2.2meq/L of emulsion, representing only a tiny increase relative to the initial value on day 0. 1H-NMR results also showed that the lowest conjugated forms and no aldehydes were detected in emulsion of 4-VG stored for 50days, proving the excellent antioxidant capacity in the O/W emulsion.