Effects of Sprouting Duration on the Physicochemical, Nutritional, Functional, and Pasting Properties of Obatanpa and Honampa Maize Flours

Abstract

Maize is an important staple crop with potential to contribute to improved nutrition. This study evaluated the effects of sprouting duration on the physicochemical, nutritional, functional, and pasting properties of Obatanpa and Honampa maize flours. With prolonged sprouting, titratable acidity (0.81–3.81%), total soluble solids (0.53–1.28 °Brix), and redness (0.62–2.48) increased, whereas pH (7.20–6.11), lightness (16.53–7.40), and yellowness (13.90–6.27) decreased in both varieties. Color difference ranged from 0.00 to 6.42, whiteness index from 6.03 to 15.01, hue angle from 0.26 to 1.51, saturation index from 6.52 to 13.98, and browning index from 82.39 to 165.72. Sprouting reduced fat (9.70–1.46%), fiber (1.98–1.50%), carbohydrate (79.42–73.91%), and energy value (1759.38–1494.14 kJ/100 g), while increasing moisture (0.66–3.82%), ash (0.60–4.03%), and protein (8.53–14.20%). Water- and oil-absorption capacities, dispersibility, and emulsion stability generally increased, whereas bulk density, loose bulk density, water absorption index, and swelling power decreased. Peak, trough, breakdown, final, and setback viscosities and peak time also declined. No pasting temperature was detected, probably because increased α-amylase activity degraded starch during heating and suppressed the viscosity response. Sprouting is therefore a low-cost approach for improving selected nutritional and functional attributes of these maize varieties.