GC-MS-SPME profiling, antioxidant, and antibacterial evaluation of ecoenzyme soap from Rockmelon ( Cucumis melo L.) peels

Rockmelon ( Cucumis melo L.) peels, rich in bioactive compounds, can be upcycled via ecoenzyme technology for cosmeceutical use. This study investigated the chemical profile and bioactivity of ecoenzyme derived antibacterial soap formulated from C . melo L. peels waste with and without whey. The formulations were evaluated for physicochemical stability, enzymatic activity, antioxidant capacity, antibacterial activity, and volatile metabolite composition using GC-MS SPME analysis. The GC-MS profile revealed diverse volatile compounds including phenolic derivatives, aromatic alcohols, and terpenoid compounds associated with antimicrobial and antioxidant functions. All formulations exhibited mildly acidic pH values (5.24–5.75) and high foam stability (82.9–95.1 %). Enzymatic assays confirmed the presence of amylase and lipase activities in ecoenzyme based soaps, indicating retained catalytic functionality after formulation. Fermented samples demonstrated enhanced antioxidant activity, with the whey enriched ecoenzyme exhibiting the strongest radical scavenging activity (IC 50 58.97 ppm). Antibacterial evaluation showed inhibitory activity against Staphylococcus aureus , methicillin-resistant S. aureus, Bacillus cereus, Bacillus subtilis , and Burkholderia glumae . The whey supplemented ecoenzyme also contain the highest phenolic (720.3 mg GAE g −1 ) and flavonoid (552.9 mg QE g −1 ) contents. These findings highlight the potential of fermented C. melo peels ecoenzyme as a sustainable bioactive ingredient for antimicrobial soap formulations and fruit waste valorisation.