Antibacterial Activity and Sensory Profile of Liquid Hand Soap from Arabica (Coffea arabica) and Robusta (Coffea canephora) Spent Coffee Grounds.

Aim/Background: The increasing consumption of coffee worldwide generates thousands of leftover coffee grounds that, when disposed of, damage the environment. The goal of this research was to create liquid hand soap from Spent Arabica (C. arabica) Coffee Grounds (SACG) and Spent Robusta (C. canephora) Coffee Grounds (SRCG) that is organic and antimicrobial and assess if they differ noticeably in their sensory profile and antibacterial activity. Materials and Methods: This study examined the soaps’ inhibitory zone against Gram-Positive (GPB) and Gram-Negative (GNB) bacteria using a quantitative research design. A modified five-point Likert scale questionnaire was used to evaluate the liquid hand soap formulation as a product. Results: A One-Way ANOVA yielded p-values of 0.00 (p-value0.05). This indicates that, with regard to GPB, there is a significant difference in the zone of inhibition between SRCG and SACG liquid hand soaps, but not with regard to GNB. SRCG displays a more significant inhibition zone than SACG in GPB, but there is no observed zone of inhibition for GNB (0 mm). Sensory evaluation for its color and aroma revealed high acceptability from the health workers, and the t-test showed that the two liquid hand soaps have no significant difference. Conclusion: SRCG has more substantial antibacterial power than SACG because of its double caffeine. Both soaps have strong antibacterial power against Staphylococcus aureus and Bacillus subtilis only. More research and tests are needed to investigate its antibacterial properties, improve the concentration and safety of the soaps, and provide better results for business application.