The degradation rates of anthocyanins are dependent on pig- ment concentration being slower with higher concentration (Merin et al., 1987). They further added that the destruction color during heating is much more rapid when oxygen is present and hydrolysis of the aglycon-sugar bond (position, 3) can occur at 100 °C (pH 2–4). Also, thermal degradation leads to the forma- tion of the chalcone and its subsequent yield of several degrada- tion products that condense to form complex brown polymeric compounds known as melanoid in pigments (Piffaut et al., 1994).