Enzymatic assay of coffee peel and papaya peel waste eco enzyme Zahrina Aufiya Kamila, Hilal Mulyadi, Suharti Suharti, Evi Susanti and Norman Yoshi Haryono BIO Web Conf., 117 (2024) 01042 Published online: 05 July 2024 DOI: 10.1051/bioconf/202411701042