Antibacterial activity of coffee.

This research demonstrates that roasted coffee has antibacterial properties. This activity is evident against a wide range of bacteria. In particular, the study considered the effect on such activity of three variables: coffee variety (Coffeaa rabica and Coffear obusta, from a total of 10 different sources), the degree of roasting (light, medium, and dark), and, finally, differences in brewing procedure. All of the roasted coffee samples examined clearly show antibacterial activity, and this activity mainly depends on the degree of roasting. This result shows that the main causes of the antibacterial activity of coffee are substances produced by the roasting process such as Maillard reaction products, carbohydrate caramelization, and thermal decomposition products.