Spent coffee ground: transformation from environmental burden into valuable bioactive metabolites

Spent coffee ground (SCG) is a primary by-product obtained during soluble coffee processing and could be used for high-value products due to its protein content. The SCG is a rich source of cellulose, hemicellulose, lignin, lipids and proteins. The bioactive peptide obtained after protein hydrolysis has great potential as an antioxidant, antimicrobial, and anti-mutagenic agent and a better understanding is a prerequisite for proper utilization of the natural and renewable source of protein to attain a sustainable approach. Moreover, by utilizing SCG-derived peptides we can reduce the contamination of these residues at an agronomical scale. In this review, we discussed the spent coffee ground protein-based peptides and also high-lightened the properties of these valuable bioactive peptides in addition to other industrially important metabolites. Conclusively, the SCG peptides can be an interesting substitute to plant protein with functional properties in food industries, and at the same time utilization of SCG would reduce the bio-waste burden.

Graphical abstract