Bioactive Compounds and Antioxidant Activity of Extracts from Musa spp. ABB group (Kluai Namwa)

Kluai Namwa (Musa spp. ABB group) is an important economic crop in Thailand, generating substantial agricultural by-products such as blossoms, peels, and pseudostems. This study aimed to enhance the value of these by-products by extracting bioactive compounds and evaluating their antioxidant potential using ABTS, DPPH, and FRAP assays. Fresh banana blossoms (large and small male florets) were blended with water (1:1 w/v), and the resulting slurry was subjected to hydraulic pressing. Meanwhile, red and white bracts and peels were blended with ethanol (1:3 w/v) and stirred for 24 h. As the pseudostem had a high moisture content (95.44%), it was directly pressed to obtain the extract for subsequent drying. The yields of banana extracts from large and small male florets, red and white bracts, peels, and pseudostem were 2.59%, 2.50%, 1.96%, 1.69%, 3.63%, and 0.93% of the wet weight, respectively. The extract from large male florets exhibited the highest levels of total phenolics (34.6 mg GAE/g extract), tannins (33.1 mg TAE/g extract), flavonoids (35.1 mg QE/g extract), and anthocyanins (17.87 µg/g extract), resulting in superior antioxidant activities, with a FRAP value of 105.84 mg Fe2⁺/g. Furthermore, this extract showed strong ABTS and DPPH radical scavenging activities of 99.92% and 83.48% at concentrations of 1 and 2 mg/mL, respectively. The results highlight the potential of banana by-products, especially the large male florets, as valuable sources of natural antioxidants, supporting waste valorization and sustainable agricultural development.