Antioxidant and antimicrobial activities of ethanolic noni leaf extract (ENLE) without and with chlorophyll removal by sedimentation method were comparatively investigated. Total chlorophyll content was reduced by 82% in the top fraction (CR‐ENLE) collected after 24 h at 4 °C as compared to that of ENLE. Antioxidant and antimicrobial activities were lower in the bottom fraction rich in chlorophyll (Chlo‐ENLE) than others (P < 0.05). Based on the microbiological limit, the shelf‐life of striped catfish slices pre‐treated with 400 mg kg−1 C‐R‐ENLE was extended to 9 days as compared to the 3 days recorded for the control (without pre‐treatment). Slices treated with CR‐ENLE had lower lipid oxidation than those treated with ENLE during refrigerated storage (P < 0.05). The sedimentation process was therefore a potential green method for producing ENLE having improved antioxidant and antimicrobial activities without green colour. It can be used as a natural additive for shelf‐life extension of fish slices.