Effect of antioxidants on the persistence of betalains in solutions

Abstract

Betalains are natural pigments found in plants and fungi. The biosynthesis of these pigments depends on the coupling between balsamic acid and an amine or amino acid, resulting in an imine or iminium salt. As a consequence, natural and unnatural betalains are attainable through semisynthesis. The major limitation for the application of these pigments is their decomposition, which occurs by hydrolysis or oxidation. Betanin, the betalain that gives color to beets, has been extensively studied because of its high added value. It is known that its decomposition is slower in solution when in the presence of ascorbic acid derivatives. This undergraduate research project proposes to investigate the effect of ascorbic acid and Trolox, a water-soluble analog of ±-tocopherol, on the decomposition kinetics of a non-natural model betalain. The results obtained will allow the rationalization of the effect of antioxidants on the persistence of betalains in aerated aqueous solution, increasing its potential of use.