Antibacterial Activity of Green Tea Kombucha-based Liquid Soap Against Body Odor (Staphylococcus epidermidis)

Body odor is commonly associated with bacterial activity on sweat, particularly that of Staphylococcus epidermidis. Kombucha, a fermented tea containing organic acids and polyphenols, has potential as a natural antibacterial ingredient. This study aimed to formulate green tea kombucha-based liquid soap and evaluate its physicochemical properties and antibacterial activity against Staphylococcus epidermidis according to SNI 4085:2017. Green tea was fermented for 14 days using a symbiotic culture of bacteria and yeast (SCOBY) and sugar, followed by liquid soap preparation using the cold-process method. The product was evaluated for organoleptic properties, pH, free fatty acids, free alkali, and antibacterial activity using the disk diffusion method. The resulting soap exhibited a yellowish color, mild aroma, high viscosity, and a pH of 10, meeting the specified quality requirements. Free fatty acid and free alkali contents were 0.15% and 0.05%, respectively, indicating effective saponification. However, no inhibition zone was observed against S. epidermidis, whereas commercial soap showed antibacterial activity at higher dilution levels. This lack of activity may be related to degradation of kombucha bioactive compounds during formulation or their limited diffusion in agar. Further formulation optimization is needed to improve antibacterial efficacy