UJI AKTIVITAS ANTIOKSIDAN DAN ANTIBAKTERI PADA KULIT BUAH KOPI ROBUSTA BERDASARKAN TINGKAT KEMATANGAN Antioxidant and Antibacterial Activity Testing of Robusta Coffee Fruit Peel Based on Maturity Level Aldi Krisdiyanto1)*, Danu Indra Wardhana1), Andika P

Antioxidant and Antibacterial Activity Testing of Robusta Coffee Fruit Peel Based on Maturity Level

Abstract

Robusta coffee peel (Coffea canephora) is an agricultural by-product that has not been optimally utilized despite containing bioactive compounds with potential antioxidant and antibacterial properties. This study aimed to determine the antioxidant and antibacterial activities of robusta coffee peel extract based on different maturity levels. The research was conducted using coffee peel at green, yellow, and red maturity stages. Extraction was carried out using the maceration method, followed by phytochemical screening, antioxidant activity testing using the DPPH method, and antibacterial activity testing against Escherichia coli using the disc diffusion method. The results showed that extract yield increased with fruit maturity, reaching 20.45% (green), 27% (yellow), and 34.22% (red). Phytochemical screening indicated the presence of alkaloids, flavonoids, saponins, and tannins. Antioxidant activity showed inhibition values ranging from 50.06% to 53.68% at concentrations of 50– 200 ppm. Antibacterial testing demonstrated inhibition zones against Escherichia coli, indicating the extract’s ability to inhibit bacterial growth. In conclusion, robusta coffee peel extract had potential as a natural antioxidant and antibacterial agent and could be developed as a value-added material in food, pharmaceutical, and health applications.