Jurnal Kimia Valensi, Vol 6(2), November 2020, 169-176 Available online at Website: http://journal.uinjkt.ac.id/index.php/valensi Copyright©2020, Published by Jurnal Kimia Valensi P-ISSN: 2460-6065, E-ISSN: 2548-3013 Isolation and Characterization of Cellulose from Banana Stems using Microwave Heating Inda Iliyin, Henny Purwaningsih*, Tun Tedja Irawadi Chemistry Department, Faculty of Mathematics and Natural Science, IPB University, Kampus IPB Dramaga, Bogor, 16680, Indonesia *Corresponding author: hennypu@apps.ipb.ac.id Received: June 2020; Revision: June 2020; Accepted: November 2020; Available online: January 2021 Abstract During each day of harvest, wasted banana stems are obtained in large quantities. These stems are composed mainly of 74.37% cellulose which is a very important raw material. This study aims to isolate cellulose from banana stems using liquefaction, delignification and bleaching processes with a microwave at power variations of 450, 600 and 800 W. The results showed that the highest cellulose content of 86.43% was obtained at 800 W for 14 minutes. Meanwhile, the fourier-transform infrared spectroscopy (FTIR) analysis result did not show a peak at wavenumber 1519 cm-1 which is the specific peak for lignin but showed a peak for cellulose at wavenumber 898 cm-1. Furthermore, XRD analysis of crystallinity showed a typical diffraction peak of cellulose at 22.5o with a degree of crystallinity of 56.8% while, morphological analysis with SEM showed that the sizes of the cellulose fibers produced varied, ranging from 5 to hundreds of micrometers and visible fibrillary fibers Keywords: Banana stem, microwave, cellulose DOI: https://doi.org/10.15408/jkv.v6i2.15962 1. INTRODUCTION Bananas have been widely planted by farmers because of its numerous benefits and high nutritional value. In Indonesia, there are 13 varieties of banana with extensive uses such as leaves, heart, tubers and roots which are currently been used by the community (Erawan et al., 2019). Based on data obtained from the Central Statistics Agency and the Directorate General of Horticulture (2019), Indonesia produces 7 million tons of banana from 107.683 ha harvest area with a productivity of 67.46 tons/ha. The use of banana trees has focused more on the fruit and leaves, other parts such as the stem have not been properly utilized. Banana stems are waste product obtained in large quantities during harvest, which makes disposal difficult (Raju et al., 2019). Therefore, the utilization of these stems into a more useful material will increase its added value. Studies have been previously carried out on the use of banana stems, such as electrodes for supercapacitors (Taer et al., 2018), nutraceutical (Ramu et al., 2017), biofilters (Sulastri and Rahmidar, 2016), antioxidants (Budi et al., 2015), paper (Malinen et al., 2014) and natural coagulants for wastewater treatment (Alwi et al., 2013). Banana stem contains 3% nitrogen (N), 0.40% sulfur and 0.25% phosphorus with protein content 8.98% being the highest (Rochana et al., 2017). The largest component contained in banana stem is cellulose, which account for 74.37% of its total composition (Lange et al., 2018). Therefore, the large quantities of banana stem waste produced have high cellulose fiber content which is the main source in producing cellulose. Cellulose provides protection and support for cells and tissues. It is composed of D-glucose subunits which are linked to each other due to the presence of β- (14)- glycoside bonds. Cellulose is most commonly found in stalks, stems, or all woody parts (Lehninger 1993) of plants and also present in