They found that the main bioactive compounds - caffeoylquinic acids, caffeine and browned compounds, including melanoidins - in the spent coffee grounds were actually four-to-seven-fold higher than in the coffee brew itself.
According to their report, the residues generated during the coffee brewing procedure can, therefore, be considered a new source of natural antioxidants and bioactive compounds.
These compounds, the scientists said, are in increasing demand by the food industry that is looking for substitutes to artificial additives, and also the pharmaceutical industry for making dietary supplements with high nutritional value or to develop new healthy products.
The report said the bioactive compounds can be easily extracted with water and, after extraction, the final residue could still be used in agriculture as fertiliser because it is practically caffeine-free.
