Effect of optimized heat-moisture treatment conditions on physicochemical and techno-functional properties of flour from four maize varieties commonly consumed in East African countries
摘要
Maize varieties commonly consumed in Uganda exhibit high starch digestibility, making them release high glucose in the bloodstream, a risk factor for non-communicable diseases. In a previous study, we optimized heat moisture treatment (HMT) conditions to reduce starch digestibility from four varieties commonly consumed (DK777, Longe 10H, UH5354, and DT Max). The current study investigated the effect of the optimized HMT conditions on physicochemical (proximate composition, total starch, amylose, and color) characteristics and techno-functional (swelling, solubility, water/oil absorption capacity, bulk density, and pasting) properties of flour from the four maize varieties. A paired sample T-test revealed that the optimized HMT conditions had no effect on the physicochemical properties of all maize varieties used in the study. However, it has various effects on techno-functional properties and depends on the variety. Swelling volume decreased by 7.29% and 13.02% for Longe 10H and DT Max varieties, respectively. Water absorption capacity increased by 6.66% for Longe 10H and 7.87% for UH5354. Oil absorption capacities and bulk densities remained constant after HMT (p > 0.05). Pasting temperature increased by 1.49%, 3.00%, 5.51%, and 10.35% for UH5354, Longe 10H, DT Max, and DK777 varieties, respectively, while holding viscosity decreased by 15.93% for DT Max and 97.78% for DK777. The observed changes could affect the maize posho quality (e.g., elasticity, cohesiveness, hardness, energy need, and cooking time), thus decreasing the acceptability of the flour. This study demonstrated that while optimizing HMT solely for decreasing starch digestibility, the conditions may affect techno-functional properties, and thus sensory acceptability of the flours.