Improvement of Robusta coffee aroma by modulating flavor precursors in the green coffee bean with enzymatically treated spent coffee grounds: A circular approach.

Spent coffee grounds (SCG) are by-products obtained from the industrial process of instant coffee production or alternatively after brewing of coffee at the point of consumption. This solid residue represents one of the largest waste materials worldwide, making this fraction a rational target for valorization. The composition of SCG varies significantly depending on the brewing and extraction methods.