Preparation and characterization of microcrystalline cellulose (MCC) from tea waste.

Microcrystalline cellulose (MCC) was prepared from Oolong tea waste by acid hydrolysis in the present study. Based on the single factor experiment results, the hydrolysis conditions were optimized by an orthogonal L9 (3)4 experiment. Results showed that the degree of polymerization (DP) and yield of MCC were strongly influenced by the time and temperature of hydrolysis, the concentration of HCl and the ratio of acid to material. Under optimal conditions (acid to materials ratio 1:20, HCl concentration 1.5 mol/L, 65 °C, 90 min), the yield and DP of the tea waste MCC were 86.7% and 145, respectively. Fourier transform-infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) analysis indicated that tea waste MCC had cellulosic structure and was cellulose I type. Scanning electron microscopy (SEM) showed that MCC had shorter fibers with some holes on the rough surface. The MCC prepared from tea waste had good thermal stability.