Research project aiming to reduce food waste and environmental impact caused by the coffee industry by up-cycling one of its by-products, coffee silverskin, as a potential food ingredient improving both functional and nutritional characteristics of the products where it is used.

The coffee industry is one of the biggest in the world and the trend is that it continues to grow, but unfortunately the industry produces side-streams on a large scale, which generates environmental problems.

Coffee silverskin (CSS) is generated during the roasting stage. It is estimated that on a global scale 76 million kg are produced annually, creating an environmental burden as it is discarded without any prior treatment. As of today, much research has been done on possible solutions and applications, yet there is no commercial applications.

CSS is composed mostly of polysaccharides, and rich in several valuable bioactive compounds that are of main interest nowadays; for instance, antioxidants, melanoidins, and acids, which confer antioxidant capacities as well as antimicrobial activity. Furthermore, CSS can act as a natural colorant and flavoring agent.

As consumers are looking for more honest and clean-label products, the use of natural sources for food additives is lately a key element, and additionally reducing food waste is another major challenge that is being addressed within this research. Therefore, in this project, thorough literature research was performed to come up with new ideas and applications of coffee silverskin, and a product prototype was developed.

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We developed a coffee silverskin extract powder through ultrasound-assisted extraction to obtain the compounds of interest. Furthermore, different analyses were performed to evaluate its composition as well as its functionality, and in the final stage, we tested the product to evaluate different potential applications for it as a food ingredient acting as a natural-sourced food additive.