COMPARATIVE PURIFICATION AND PHYSICOCHEMICAL CHARACTERIZATION OF WASTE COOKING OIL FOR DEVELOPMENT OF VALUE-ADDED CONSUMER PRODUCTS

Waste edible cooking oil (WCO) is produced in substantial quantities worldwide and poses significant environmental and public health concerns when improperly managed. The present study investigates the purification, physicochemical characterization, and value-added utilization of WCO for the development of surface disinfectant, handwash, and candle formulations. Three purification approaches—activated charcoal adsorption, sulfuric acid treatment, and sedimentation—were comparatively evaluated based on colour, odour, free fatty acid content, saponification value, peroxide value, moisture content, and viscosity. Cytotoxicity evaluation using the lactate dehydrogenase (LDH) release assay indicated markedly reduced toxicity in purified oil compared to untreated WCO, emphasizing the necessity of purification prior to reuse. The refined oil was successfully employed for the formulation of household and personal care products. Antibacterial assessment demonstrated effective inhibition of Escherichia coli, Salmonella typhi, and Listeria monocytogenes. The findings highlight the feasibility of converting WCO into functional, eco-friendly products, supporting sustainable waste management and circular economy practices.