Time-resolved effects of selected processing methods on the biochemical composition, antioxidant capacity, and techno-functional properties of mung bean flour

Abstract

Mung bean is protein-rich but constrained by anti-nutrients; processing method and duration jointly shape its nutritional and functional profile. This study systematically compares germination (24/48/72 h), blanching (3/5/7 min), and sonication (10/20/30 min) of N-26 mung bean flour to map time–responses across proximate composition, anti-nutrients, bioactives/antioxidants, techno-functional traits, pasting/rheology, thermal behavior, and starch crystallinity. Data from standard analytical methods, measured in triplicate, were subjected to one-way ANOVA followed by Tukey’s post hoc test (p < 0.05) to assess statistical significance. Germination increased protein (25.8 to 32.5% at 72 h) and markedly elevated total polyphenols (to 15.2 mg GAE/g), flavonoids (9.1 mg/g), and antioxidant capacity (DPPH 96.7%, ABTS 97.5%), while blanching most effectively reduced phytic acid (from 5176 to 4092 μg/g). Sonication maximized water solubility (to 24.8%) and final viscosity (1894 cP), whereas germination induced a downward viscosity trend. Dynamic rheology indicated predominantly elastic behavior (G′>G″; tan δ<1) with softening at 72 h germination (tan δ≈1.15). Differential scanning calorimeter showed lower onset temperatures in processed samples; XRD revealed attenuated crystallinity/peak shifts consistent with macromolecular remodeling. Together, the processing methods and time interaction is decisive: blanching is optimal for rapid anti-nutrient removal, 72 h germination for protein and bioactives, and 20–30 min sonication for solubility and viscosity. These findings provide application-specific windows for precision processing of mung beans for various nutritional and techno-functional targets.