3.1. Surface morphology images of WFC
Surface morphology images of WF and WFC are shown in Fig. 2. In previous studies, chemical treatments with acid or alkali could cause the structural modification affecting the technological properties of insoluble fiber (Alemdar and Sain, 2008 and Kuan et al., 2011). Thus, it could be expected that acidic condition during coloring could influence the microstructure of WF.