Iradisnayanti Sihombing, Evi Suaebah, Ersyzario Edo Yunata, Jan Ady
Honey orange, a distinct citrus variety known for its honey-like sweetness, thrives abundantly throughout Indonesia, appealing to a broad consumer base. Unfortunately, the waste generated from honey orange peel remains vastly underutilized. Honey orange peel exhibits significant potential as a natural antibacterial source, necessitating an in-depth investigation. The extraction process of honey orange peel was conducted using the Soxhlet method, yielding an extract volume of 585?ml from 122 grams of peel material. The different concentrations (50%, 37.5%, 25%, and 12.5%) were mixed with precursors (CuSO4.5H2O) for an antibacterial study. The Fourier-Transform Infrared (FTIR) analysis revealed the detection of functional groups of flavonoid compounds in the honey orange peel extract, with additional detection of O-H functional groups at the wavenumber of 3309.24?cm-1. X-ray Diffraction (XRD) testing indicated the formation of copper (II) oxide (CuO) in the volume fraction range of 2% to 25%. Particle Size Analysis (PSA) demonstrated that the concentration variations resulted in particle sizes ranging from 2?μm to 5?μm. Bacterial testing using the disc diffusion method indicated that bacterial growth was maximally inhibited at concentrations of 12.5% and 25%, resulting in inhibition zones of (26.31 ± 0.16) mm and (25.53 ± 0.31) mm, respectively, against Escherichia coli. Based on the characterization results, this study underscores the potential utility of honey orange peel extract as an antibacterial agent. © 2025 Author(s).
Department of Physics, Faculty of Science and Technology, Airlangga University, Surabaya, 60115, Indonesia; Department of Physics, Faculty of Mathematic and Natural Science, Universitas Negeri Surabaya, Surabaya, 60231, Indonesia