The effect of dewaxing of green coffee on the coffee brew

The two commercially most important mild treatments for green coffee are the steam treatment and the dewaxing process. In the former treatment the green coffee is just steamed. In the dewaxing process the waxy layer is extracted from the green coffee with an organic solvent, after which this coffee is also steamed to remove solvent residues. Some of the main constituents of the waxy layer are the carboxy-5-hydroxytryptamides (C-5-HT). What happens to these components during the roasting and brewing of the coffee is discussed. During roasting part of the C-5-HT decomposes, but during brewing most of the C-5-HT remains in the spent grounds due to its insolubility.Literature reports about physiological effects of both types of coffee in human and animal experiments are summarised briefly. For both types of treated coffee additional evidence seems to be needed before hard conclusions can be drawn about their digestibility.