Utilization of Coleus scutellarioides Leaf Extract as an Antimicrobial Active Ingredient in the Production of Solid Soap from Used Cooking Oil

Abstract

Soap is the result of a chemical reaction between fatty acids (triglycerides) and alkali, producing soap and glycerol. One of the common sources of triglycerides in our surroundings is used cooking oil. While used cooking oil can be utilized as a raw material for soap production, it has a drawback namely, a high content of free fatty acids. Therefore, an adsorption process is required to reduce the free fatty acid content before the oil can be used in soap making. The aim of this study is to examine the effect of adsorbent concentration specifically using sugarcane bagasse and adsorption duration on the quality of used cooking oil. The variables in this study include the concentration of sugarcane bagasse adsorbent ranging from 0% to 10%, and the duration of the adsorption process from 0 to 96 hours, both aimed at reducing the free fatty acid content in the used oil. Additionally, the study evaluates the effectiveness of Coleus atropurpureus (Jawer Kotok) leaf extract, which has been separated from ethanol solvent using a rotary evaporator, as an antimicrobial agent in soap, with varying concentrations from 0% to 2%. The results indicate that the optimal adsorbent concentration for reducing free fatty acid content is 7%, with an optimal adsorption duration of 72 hours. The optimum concentration of Coleus atropurpureus extract for antimicrobial effectiveness in soap formulation is 2%.