Enhancing Soap Formulation from Waste Oil: An Analysis of Properties and User Satisfaction Using Taguchi Method

This research centers on modifying and optimizing waste oil soap formulation using Taguchi design of experiments (DOE). The aim of the study is to find optimal soap parameters with respect to the input variables such as water, NaOH, waste oil and agarwood dust. The output parameters to be investigated are pH, foaming rate, antimicrobial activity, and hedonic results which measure appearance, odor, textural properties, color, and general acceptability. Based on the hedonic results, Taguchi analysis reveals the rank order of parameters that influences the quality of the soap and it was noted that waste oil is the most important parameter followed by agarwood dust, water and NaOH. The optimal formulation determined consists of coconut oil, 70 ml of water, 2 g of agarwood dust, and 15 g of NaOH. Detailed properties analysis and the regression equation for this formulation are included to provide a comprehensive understanding of the soap's performance. This systematic approach not only enhances the soap’s quality but also promotes the utilization of waste oil, contributing to environmental sustainability.