RESUMEN
Spent coffee grounds (SCG) or coffee residue wastes (CRW) provide excellent raw material for mannose and bioethanol production. In this study, SCG were used to produce valuable biosugars, including oligosaccharides (OSs), manno-oligosaccharides (MOSs), mannose, and bioethanol. SCG were subjected to delignification and defatting, producing SCG-derived polysaccharides. Two-stage enzymatic hydrolysis (short- and long-term) was performed to produce short-chain manno-oligosaccharides (MOSs) and monosaccharides (MSs), respectively. From 100â¯g dry weight (DW) amounts of SCG, approximately 77â¯g delignified SCG and 61â¯g SCG-derived polysaccharides, amounts of 15.9â¯g of first biosugars (mostly MOSs), 25.6â¯g of second biosugars (mostly MSs), and 3.1â¯g of bioethanol, were recovered. This technique may aid in the production of high-value mannose and OSs from SCG and other lignocellulosic biomasses that contain specific polysaccharides.
Asunto(s)
Café/metabolismo , Manosa/biosíntesis , Oligosacáridos/biosíntesis , Café/química , Hidrólisis , Polisacáridos/metabolismoRESUMEN
Nowadays, coffee residue (CR) after roasting is recognized as one of the most useful resources in the world for producing the biofuel and bio-materials. In this study, we evaluated the potential of bio-sugar and bioethanol production from acid-chlorite treated CR. Notably, CR treated three times with acid-chlorite after organic solvent extraction (OSE-3), showed the high monosaccharide content, and the efficient sugar conversion yield compared to the other pretreatment conditions. The OSE-3 (6% substrate loading, w/v) can produce bio-sugar (0.568g/g OSE-3). Also, simultaneous saccharification and fermentation (SSF) produced ethanol (0.266g/g OSE-3), and showed an ethanol conversion yield of 73.8% after a 72-h reaction period. These results suggest that acid-chlorite pretreatment can improve the bio-sugar and bioethanol production of CR by removing the phenolic and brown compounds.