en تخصصي Special مقاله اصیل Original Article <div style="text-align: justify;">Background: This study explores the initial application of chitosan combined with bio-oil to create an edible coating for preserving Indian mackerel (Rastrelliger kanagurta).<br> Methods: Chitosan was extracted from shrimp shells, and bio-oil was produced through the pyrolysis of coconut shells at 350 &deg;C and subsequently purified using adsorption or distillation. Various formulations of the edible coating were created with chitosan concentrations of 0%, 2%, 4%, 6%, and 8%, combined with bio-oil concentrations of 3% and 5%. The Indian mackerel samples were immersed in the edible coating for 20 minutes to promote preservation. The quality and freshness of the Indian mackerel were assessed every 24 hours over a three-day storage period. GC-MS analysis confirmed the presence of phenolic chemicals and acetic acid in the bio-oil, both of which have antibacterial effects.<br> Results: The findings indicated that the optimal edible coating formulation contained 5% bio-oil and 8% chitosan, resulting in a total volatile base (TVB) of less than 30 mg N 100 g of sample and a total plate count (TPC) of less than 1&times;10&sup3; CFU/mL.<br> Conclusion: The use of chitosan and bio-oil obtained from coconut shells as an edible coating is efficient in preserving mackerel by inhibiting microbial growth and maintaining sensory quality. Pyrolysis, followed by adsorption purification or distillation, provides a natural and environmentally beneficial alternative to synthetic fish preservatives.</div> Antibacterial agents, Bio-oil, Chitosan, Edible films, Pyrolysis 1 11 http://ehemj.com/browse.php?a_code=A-10-1-406&slc_lang=en&sid=1 Khalimatus Sa’diyah khalimatus.s@polinema.ac.id 100319475328460021633 100319475328460021633 Yes Corresponding author: Department of Chemical Engineering, State Polytechnic of Malang, Malang, Indonesia Agung Ari Wibowo agung.ari@polinema.ac.id 100319475328460021634 100319475328460021634 No Department of Chemical Engineering, State Polytechnic of Malang, Malang, Indonesia Susanto Susanto susanto.s@polinema.ac.id 100319475328460021635 100319475328460021635 No Department of Chemical Engineering, State Polytechnic of Malang, Malang, Indonesia Cucuk Evi Lusiani lusiani1891@polinema.ac.id 100319475328460021636 100319475328460021636 No Department of Chemical Engineering, State Polytechnic of Malang, Malang, Indonesia Ernia Novika Dewi ernianovika@polinema.ac.id 100319475328460021637 0009-0005-8800-9142 No Department of Chemical Engineering, State Polytechnic of Malang, Malang, Indonesia