that the amounts of impurities (protein and ash) in the insoluble FRFs were about 9.43–16.2 g/100 g FRF, while the other non-sugar components ranged from 41.3 to 47.5 g/100 g FRF. Among the sugars of the insoluble FRFs, the predominant sugars were glucose (50.1–53.7%) and xylose (17.7–22.4%), followed by arabinose (10.7–14.8%), uronic acid (7.05–
9.07%), rhamnose (1.48–4.94%) and galactose (2.67–3.27%). The high proportion of cellulosic glucose (43.1–
52.4%) revealed that cellulose was the major polysaccharide in the insoluble FRFs.