Abstract
The study investigated the impact of malting and fermentation durations on the antioxidant
activity, chemical, functional, and microstructural attributes of pearl millet cultivars (Agrigreen
and Babala) and sorghum flour. Employing response surface methodology with a central
composite design, 24, 48, and 72 intervals were tested. Results revealed significant (p < 0.05)
alterations in total phenolic content (TPC), total flavonoid content (TFC), ferrous reducing
antioxidant power (FRAP), 2,2-diphenyl-1-picryhydrazyl (DPPH), and other properties. Babala
flour displayed the highest TPC (34.02–36.62 mg GAE/100 g), while Agrigreen had the highest
TFC (9.76–18.22 mg Que/100 g), FRAP (0.268–1.168), and DPPH (57.68–70.04%) content. Various
phenolic compounds were identified, including quercetin-3-O-glucoside, hesperetin, and
petunidin. Babala flour exhibited higher pH (4.78) compared to Agrigreen (5.50) and sorghum
(4.92), while Agrigreen showed higher total titratable acidity (TTA) (0.159%) than sorghum and
Babala. Babala flour also demonstrated a higher water absorption capacity (WAC ) at 2.37 ml
g−1, while sorghum exhibited the lowest oil absorption capacity (OAC ) at 1.67 ml g−1. Agrigreen’s
malted and fermented flour had the lowest bulk density (0.53 g ml−1), while sorghum flour
had the highest dispersibility (56.34%). Morphological changes included varied shapes from
isolated to smoother surfaces. Optimal processing times significantly impacted antioxidant
activity and other properties, with potential applications for food processing companies
seeking to enhance pearl millet and sorghum products.