Effects of Blanching on Phytochemical Retention, Antioxidant Capacity, and Microstructure of Banana Flower (Musa spp., Musaceae).

Banana flower (Musa spp., Musaceae) is an underutilized agricultural by-product rich in dietary fiber, phenolic compounds, and antioxidants. However, its rapid deterioration and enzymatic browning may necessitate the implementation of effective pretreatment strategies to facilitate the preservation of its nutritional and functional quality. The present investigation evaluated the potential influence of microwave blanching, citric acid immersion, and hot-water blanching on the phytochemical profile, antioxidant activity, microstructural characteristics, and thermal properties of banana flower. Banana flowers were subjected to microwave blanching (720 W for 30, 35, and 40 s), citric acid immersion (1%, 3%, and 5%), and hot-water blanching (100°C for 1, 3, or 5 min). Proximate composition, total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity (DPPH, ABTS, and FRAP assays), scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) analyses were performed. Data were analyzed using two-way ANOVA, and significant differences among treatment means were evaluated using appropriate post hoc tests at p < 0.05. Fresh banana flower contained 71.15% moisture, 13.01% crude fiber, 5.58% protein, 4.45% fat, and 3.71% ash, which may indicate substantial nutritional potential. Among all treatments, microwave blanching for 40 s (MW40) exhibited the highest TPC (7.60 mg GAE/g) and TFC (4.90 mg QE/g), alongside elevated antioxidant capacities in DPPH, ABTS, and FRAP assays (p < 0.05). SEM analysis revealed extensive pore formation and cell-wall disruption, while XRD showed a reduction in crystallinity index to approximately 29.7%, which may suggest enhanced amorphization and improved extractability of bound phenolics. DSC analysis demonstrated that MW40 retained considerable thermal stability (ΔH = 180.27 J/g) compared with hot-water-blanched samples, thereby potentially indicating the preservation of molecular integrity despite structural modification. Optimized microwave blanching (720 W, 40 s) enhanced bioactive compound retention, antioxidant capacity, and extractability while preserving favorable thermal characteristics of banana flower. These findings support its potential as a pretreatment strategy for functional food ingredients; however, further optimization and storage stability studies are required to confirm adequate enzymatic stabilization and industrial applicability. Future studies should investigate storage stability, the bio-accessibility of bioactive compounds, and industrial-scale applications of microwave-blanched banana flower.