Effect of laccase oxidation on phenol content and antioxidant capacity of roasted coffee

Abstract

The endogenous enzyme in fresh coffee beans mostly is from the class of oxidoreductase. However, those enzymes have low effectiveness in phenolic compound oxidation. The fermentation of conventional coffee processing requires a longer time. The ability of laccase could shorten the time of fermentation. Therefore, need exogenous enzyme such as laccase. Laccase is an enzyme that able to degrade lignin. In this study laccase from Trametes versicolor is effective for phenol oxidation and able to reduce bitterness in coffee beans. The bitterness of coffee beans is caused mostly by phenolic compounds in coffee such as chlorogenic acid,caffeic acid, and ferulic acid. This study aims to determine laccase oxidation in coffee beans quality by measuring phenol content and antioxidant capacity. The results showed that the lowest total phenol (0.73 ± 0.103 mg/ml) was achieved by laccase oxidation using ABTS as a mediator with antioxidant capacity level as 91.58 ± 0.001%. The benefit of this research is making the best quality of coffee beans with high antioxidant capacity and low phenol content so that it does not require added sweeteners or sugar that can interfere with health.