PREPARATION OF NANOCRYSTALLINE CELLULOSE FROM TOMATO STEM AND COMMERCIAL MICROCRYSTALLINE CELLULOSE: A COMPARISON BETWEEN TWO STARTING MATERIALS

摘要

Nanocrystalline cellulose was prepared from locally abundant tomato stem. Initially, chemical treatment was performed to remove the non-cellulosic constituents of tomato stem. Isolation involves a combination of acid hydrolysis and ultrasonic treatment. The shape and size distribution of the resulting NCC were determined using particle size analysis, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images. The thermal properties, surface functional groups, sulfur content and crystallinity of the NCC derived from tomato stem were compared to those of the NCC prepared from commercial microcrystalline cellulose (MCC). The morphology of NCC obtained from tomato stem has an interconnected web-like structure and the crystallinity index was calculated as 74.4%. The suspension of the NCC derived from tomato stem was very stable and could be stored for at least three months without sedimentation, which was confirmed by particle size and zeta potential measurements. The economic competitiveness of NCC production is dependent on feedstock costs. As demonstrated in this study, waste tomato stem can be a good low-cost alternative for NCC isolation.