Natural Antibrowning Agents against Polyphenol Oxidase Activity in Annona muricata and Musa acuminata

Abstract

Fresh-cut fruits and vegetables emerge as popular food for consumers in retail markets. However, a loss of millions of dollars yearly to the food industry has been due to discoloration of fruits and vegetables caused by a pronounced reaction called enzymatic browning, which is caused by the activity of the polyphenol oxidase enzyme present in most of the fruits and vegetables. The main objective of this study was to investigate the natural antibrowning effects of the aqueous extract of ginger and essential oil of cinnamon bark on PPO enzymatic activity in Annona muricata (katu anoda) and Musa acuminata (ash plantains), which are considered to be widely consumable by Sri Lankans due to its respective health benefits. The antibrowning activity analyzed using a UV-visible spectrophotometer at a wavelength of 525 nm showed that cinnamon bark oil of 0.0035 g/mL had a % inhibitory activity of 51.97 percent on PPO activity in Annona muricata and 49.51 percent on PPO activity in Musa acuminata, while the aqueous extract of ginger of 0.091 g/mL had a % inhibitory activity of 60.90 percent on PPO activity in Annona muricata and 48.10 percent on PPO activity in Musa acuminata, respectively. This study shows that cinnamon bark oil and ginger can be used as effective, natural, nontoxic antibrowning agents that can inhibit the activity of the PPO enzyme, thereby preventing the essence and nutritional benefits of fruits and vegetables.