Phenolic compound derived from microwave-assisted pyrolysis of coconut shell: Isolation and antibacterial activity testing

¹ Chemical Engineering Department, Faculty of Engineering, Universitas Negeri Semarang, 50229 Gunungpati, Semarang, Indonesia
² School of Chemical and Energy Engineering (FCEE), Faculty of Engineering, Universiti Teknologi Malaysia (UTM) 81310 Skudai, Johor Bahru, Malaysia

^* Corresponding author: ratnadewi.kusumaningtyas@mail.unnes.ac.id

Abstract

Indonesia is rich in natural resources, coconut plantation being one of them. The coconut processing industry produces coconut shell (CS) waste. The most effective technique to increase the value of this waste is to convert CS biomass through pyrolysis process. This research focuses on intensification of conversion process of CS by Microwave-Assisted Pyrolysis (MAP) to obtain PA. PA contains phenolic compounds which have antibacterial properties so they can be formulated as an antibacterial agent. CS has moisture and ash content of 8.89% and 0.21%, respectively. PA was produced from the MAP of CS at 600W at 450℃ and 500oC for 10, 20, and 30 minutes. The PA was extracted using ethyl acetate to obtain phenolic contents. Optimum pyrolysis condition was found at 400^oC for 30 minutes and yield of PA was determined at 32.20 g with total phenolic content (TPC) of 112.13 mg GAE/g. The inhibition zone of phenolic extract from coconut shell (PECS) using E. Coli was determined within 22-25 mm that quantitatively PECS can effectively kill bacteria. PECS by MAP and its aplication as an antibacterial agent has never been performed, so this work is an important contribution in the intensification of pyrolysis and in medical field.