Valorisation of coffee roasting by‑products : recovery of silverskin fat by supercritical CO2 extraction

Recovery of agro and food-industrial waste and their valorisation via green technologies can help to outline new concepts of industrial strategies. In this contest, a fat enriched of added-value components was extracted from cofee silverskin by applying a supercritical fuid extraction technique (sc-CO2). An appropriate modulation of process parameters like temperature (T=35, 50, 60 °C) and pressure (p=200–300 bar) infuences the fat yield and the chemical composition, opening the way for targeted extraction. The extraction time, the organic solvent use and the energy consume were reduced compared to Soxhlet. Moreover, a mathematical model was constructed based on the experimental data collected, employed apparatus, and physico-chemical characteristics of biomass, pointing to a possible industrial scale-up. The experimental results are accompanied by a preliminary cost of manufacturing (COM), highlighting how the high investment for the apparatus is compensated by several benefts.