Title
Isolation and characterization of microcrystalline cellulose from fennel stems agro-waste
Authors
UMA HAPANI and LINZ-BUOY GEORGE

Received February 14, 2025
Published Volume 60 Issue 1-2 January-February
Keywords acid hydrolysis, fennel stems, microcrystalline cellulose, properties

Abstract
For the current work, cellulose was isolated from the stems of fennel (Foeniculum vulgare Mill.), using combined chemical treatments such as dewaxing, delignification, and bleaching. The extracted cellulose was successfully used for the preparation of microcrystalline cellulose (MCC) by the acid hydrolysis process. For the comparative study, the obtained fennel stem (FS) microcrystalline cellulose (FS-MCC) was characterized along with the raw fennel stem (RFS) and fennel stem cellulose (FS-C). The chemical composition study confirmed that the content of α-cellulose in RFS increased from 45.75% to 59.64% in FS-MCC. Further, FS-MCC was examined by Fourier transform infrared (FT-IR) spectroscopy, which confirmed an improved structure of α-cellulose. X-ray diffraction (XRD) analysis confirmed that crystallinity increased from 37% to 74%. The scanning electron microscopy (SEM) showed a rough surface and a reduction in the fibre size that indicates the complete removal of non-cellulosic constituents from FS-MCC. Differential scanning calorimetry (DSC) proved that the isolated FS-MCC had a high thermal degradation temperature (393.77 ℃), compared to the RFS (336.54 ℃). In addition to this, Brunauer-Emmett-Teller (BET) analysis of FS-MCC showed higher surface area and total pore volume (1.49 m2g−1, 0.0028 cm3g−1) compared to the of FS-C (0.39 m2g−1, 0.0024 cm3g−1). In the view of overall results, the prepared FS-MCC could offer great potential in future applications.