Antioxidant Activity of Banana Peel Waste, the Development and Stability Evaluation of Facial Toner Containing Banana Peel Extract

The banana processing industry produces many by-products, mainly banana peel. Banana peel waste, after banana processing, can be a good source of bioactive compounds. Extraction of phenolic compounds using optimum extraction conditions enhances the yield and quality of the products. This study evaluated optimizing the extraction time for the maximum extraction yield from banana peels, consequently lowering the overall process cost. In addition, the application of increasing the value of banana waste was also evaluated. The optimum conditions were achieved using 95% ethanol with a solid-to-liquid ratio of 1:5, 25 ± 5 oC under various extraction times (0-96 h). The responses, such as total phenol content (TPC), total flavonoid content (TFC), and DPPH inhibition activity, were measured by spectrophotometric analysis. The optimal incubation time at 72 h was found to be more effective compared to the others. The values of TPC, TFC, and DPPH inhibitory activity at optimized conditions were 8.23 ± 0.42 mg gallic acid equivalent (mg GAE)/g, 8.18 ± 0.08 mg quercetin equivalent (mg QE)/ g, and 93.96%, respectively. The ethanolic extract of banana peel had an inhibition concentration (IC50) of 48.35 ± 0.88 μg/mL. After that, banana peel extract was subjected to study the potential for cosmetic application. The extract was applied as an ingredient in facial toner. The toners were preliminarily characterized. Banana peel waste possesses reasonable antioxidant activity and shows high stability over time. The results showed high potential for cosmetic applications using banana peel extract. In addition, using banana peel waste reduces agricultural waste in the environment.