| Anthocyanins are natural pigments responsible for red, purple, and blue coloration in plants. Human consumption of anthocyanins is increasing because of the rising awareness and interest in their potential health benefits. Pomegranate is one of the major source of polyphenolic phytochemicals, such as anthocyanins. Dried pomegranate raisins (anardana) are consumed in large quantities in Asian countries, and contain substantial amount of anthocyanins.;Five anthocyanins were found to be present in pomegranate raisins. Drying adversely affects the amount of anthocyanins, with polyphenol oxidase (PPO) playing a possible role in oxidative degradation of anthocyanins. In fresh pomegranate arils with intact cellular matrix, the intracellular membranes, such as those surrounding the vacuoles and other organelles, provide the compartmentalization that separates the anthocyanins from oxidative enzymes, such as PPO. Disruption of cellular membrane during processing leads to loss of this intracellular compartmentalization, resulting in the enzyme-substrate contact, and oxidative degradation of anthocyanins. Anthocyanins are heat stable compounds. Drying the pomegranate arils at high temperature for short period inactivates PPO, which may prevent the PPO-catalyzed anthocyanin oxidation, resulting in high anthocyanin containing raisins. |
