Integrated green process for efficient mannose and mannooligosaccharides production from spent coffee grounds

Mannans, the predominant component in spent coffee grounds, can be transformed into mannose and mannooligosaccharides. These derivatives serve as valuable prebiotics and bioactive components in the functional food and pharmaceutical industries. In this study, two eco-friendly pretreatment techniques were utilized to process spent coffee grounds, enhancing the release of valuable sugars and improving (3-mannanase accessibility, thereby increasing the yields of mannose and mannooligosaccharides. Following a combined treatment with laccase and cellulase, most soluble sugars were efficiently produced via microwave hydrothermal treatment at 210 degrees C for 30 min. From 1 g of defatted spent coffee grounds, 74.2 mg of mannose and 121.1 mg of mannooligosaccharides were obtained, representing 83% of the total mannose content. This method has proven to be an efficient way to utilize spent coffee grounds, with significant implications for their high-value conversion and utilization.