Food waste biorefinery: A case study for spent coffee grounds (SCGs) into bioactive compounds across the European Union

Implementation, development, and processing of food waste biorefinery from the spent coffee grounds (SCGs) potentially depend on characteristics and availability of those residues, further the economic interest on the products to be obtained. In the European Union (EU), the quantity of SCGs available only from coffee manufactories corresponds to more than 330, 000 tons/year. Their disposal represents a severe environmental problems, as they consists of high concentrations of several hazardous organic pollutants mainly including polyphenols, melanoidin, xanthine, tannin, diterpene, carotenoids, due to the decomposition of SCGs with high oxygen consumption. So, SCGs could be valorized within a coffee-based bio-refinery concept to yield various value added products, namely, biofuels and polyhydroxyalkanoates (PHAs). Consequently, this chapter is mainly focused on the bioconversion of SCGs into value based products and issues, relating to the implementation of a biorefinery approach. Here, the analysis has started with characterizing the SCGs followed by which products may be obtained from it, for a SCG based biorefinery mainly via liquid polyols, carotenoids, bio-sorbents, biofuels, and biopolymers. Subsequently, the potential issues behind it have been discussed.