Valorization of products from grounded-coffee beans

Sci Rep. 2021 Oct 14;11(1):20445. doi: 10.1038/s41598-021-99938-x.

Abstract

The valorisation of ground coffee beans is discussed in two parts; the first research question relates to the extraction of cold brew from ground coffee beans to provide a healthy cold beverage. Two parameters were investigated: temperature, and the ratio of ground coffee beans to water. This work suggests that cold brew coffee can be extracted between 15 and 20 °C over 2 to 4 h instead of 24 h as outlined in typical cold brew extraction processes. The coffee aroma was the response variable. Part of this investigation was to develop a downstream product from the waste spent grounded coffee bean. This part of the study investigates the production of firelighters from spent ground coffee beans to reduce the impact of dumping significant quantities of spent coffee grounds from coffee houses, restaurants, and baristas on landfill sites, which can lead to environmental problems such as polluting water systems, killing wildlife and disturbing ecosystems. The study used spent ground coffee beans in products such as firelighters to test their efficacy. This application has shown promising results, with the firelighters showing longer burning times for the ignition of log fires while also emitting a gentle, pleasant coffee aroma.