Visual analysis of the morphological features and polysaccharide distribution of raw ramie and their influence on degumming

The morphological features of raw ramie and the distribution of polysaccharides on such features were investigated using various microscopes to reveal the pivotal factors that influence microbial degumming efficiency. Results indicated that the morphological features mainly included fence, chunk, membrane, ribbon, and plank shapes. The various morphological features had their respective coverage characteristics. The fence and chunk shapes distributed on the membrane shape and cemented the fiber bundle. The ribbon shape was covered by the plank shape in several locations, and they covered one lateral surface of the fiber bundle as an integral. All of these morphological features were not observed in the refined fiber, indicating these features belonged to gum that consists of non-cellulosic components traditionally. However, some cellulose was also found in these features and should be classified as a new kind of gum component because this part of cellulose was not used for weaving. Apart from cellulose, the membrane shape contained mannan and xylan, and the fence and chunk shapes contained pectin, but the ribbon and plank shapes contained three of them. What’s more, the xylan on the membrane and ribbon shapes was masked by several components, and the mannan on the membrane and plank shapes was also masked. Furthermore, the coverage characteristics of the morphological features and the masking relationship (cross-linking) among polysaccharides influenced the contact degree between the enzyme and gum and further degumming efficiency. Increasing the contact degree between the enzyme and gum is a pivotal factor for improving degumming efficiency.