Characterization of physicochemical properties of cellulose from potato pulp and their effects on enzymatic hydrolysis by cellulase

In this work, cellulose was extracted from potato pulp, a low-efficiently utilized by-product from potato starch industry, by a combined alkali and sodium sulfite treatment. Its physicochemical properties were characterized and compared with cellulose from corn stalk. The yield and purity of cellulose from potato pulp were determined to be 24.74% and 81.34% respectively. Cellulose from potato pulp had more loosened and porous structure, lower crystallinity index and larger specific surface area (SSA) compared with cellulose from corn stalk. It also provided the highest accessibility to cellulase (5.7 mg protein/g glucan) and had the highest enzymatic digestibility (with glucose yield of 88.46%). Maximum adsorption capacity (W_max) and equilibrium constant (K) were obtained by fitting the adsorption data with the Langmuir adsorption isotherm, suggesting that cellulose from potato pulp had the highest cellulase adsorption efficiency. The data further indicated that the presence of non-cellulosic components, especially for pectin, appeared to have a considerable effect on the hydrolysis by cellulase due to non-productive adsorption. State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue Wuxi 214122, Jiangsu Province, People's Republic of China.