Qualitative phytochemical Screening of Sri Lankan Fruit Processing Biowastes: Implications for Valorization

Fruit processing biowastes are abundant, underutilized sources of bioactive compounds with significant potential for valorization into value-added products. This study screened the phytochemical profiles of three commonly available Sri Lankan fruit biowastes: banana peel (Musa spp.), orange peel (Citrus sinensis), and mango (Mangifera indica) seed and seed coat collectively. Samples were dried at 40°C and 60°C, and extracted using three methods: ethanolic extraction, room-temperature aqueous extraction, and hot-water aqueous extraction, yielding a total of eighteen distinct extracts for qualitative phytochemical analysis. Qualitative tests revealed the consistent presence of steroids, cardiac glycosides, phenols, flavonoids, terpenoids, and quinones across all three biowastes and all extraction types, with phenolic and flavonoid intensities comparatively lower in banana peel extracts. Tannins and coumarins were prominent in mango seed and orange-peel extracts but were largely absent in banana peel extracts. Tannins were detected only in ethanolic extracts, whereas no tannins were observed in either room-temperature aqueous or hot-water aqueous extracts. Anthraquinones were detected only in the hot water extract of banana peel, and were absent in all other extracts. Phlobatannins and phytosterols were not detected in any sample tested. These findings indicate that mango seed and orange peel biowastes possess broader and more stronger bioactive profiles than banana peel, highlighting their potential as promising sources of natural bioactive compounds for value-added applications. This preliminary assessment demonstrates the potential for valorization of underutilized fruit processing by-products generated within Sri Lanka's fruit processing industry.