Observation of Bitterness Reducing Ability of Melastomataceae Leaf Extracts on Caffeine and Coffee Powder

Abstract

Abstract: Aim: The research aims to measure the reduction of bitterness of coffee by Melastomataceae leaf (DM) extracts measured by caffeine and polyphenol concentrations and changes in covalent bonds observed with Fourier Transformed Infra-Red (FTIR). Method: The ethyl acetate, ethanol absolute, and aqueous extracts of Melastomataceae leaves were prepared by overnight maceration followed by dehydration at 50±5 °C. Commercial coffee powder (K) and caffeine standard (CF) were mixed with each extract at ratio of 1:2 and 1:9 (w/w), respectively. Caffeine and polyphenol were spectrophotometrically measured. Dried samples were subjected to FTIR analysis to observe changes in the IR profiles. Results: Reductions of caffeine in CF and K were optimum with ethyl acetate extract of DM. The reduction of bitterness of coffee was related to covalent bonds at IR detection range of 1000- 1800 and 2500-3700 cm-1. Conclusion: Melastomataceae leaf can be applied to reduce bitterness on coffee related product. The ethyl acetate extract emerged as the most effective bitterness reducing agent.