Development of a Stealth Health Approach to Improving Lysine Consumption in Nigeria With a Focus on Urban Populations

ABSTRACT Since the Green Revolution, the intake ratio of cereal grains to pulses has increased considerably, coinciding with marked declines in dietary quality, specifically protein and fiber consumption. Prominent increase in consumption of bread formulated with wheat flour has exacerbated the decrease in dietary quality, characterized by a decrease in lysine—a limiting essential amino acid in the diet relative to protein quality. We examined the impact of Nigerian cowpea, US cowpea, US roasted cowpea, and common bean flours on protein and amino acid levels, as well as measures of bread quality. Using a dose–response approach to substitution, the impacts of improving the nutritional quality of bread are juxtaposed with effects on traditional metrics of bread quality. Substitutions of wheat flour with 1%–50% with cowpea or common bean flour were assessed, and impacts on the antinutrient lectin were also evaluated. Up to 5% substitution with either pulse flour type did not diminish bread quality. We observed that cowpea flours had higher protein concentrations (21%–23%) than common bean flours (~19%), and cowpea flour from Nigeria had 10% higher protein content, resulting in 12% larger loaves than cowpea sourced from the USA. Comparison of common bean varieties (Rattler and Diamondback) showed only small differences in water absorption; otherwise, bread quality was not affected by variety. Roasting of the US cowpea prior to milling had no effect on loaf volume or water absorption. At higher pulse flour percentages (10% and 20%), adding ascorbic acid (AA) and vital wheat gluten (VWG) improved the loaf volume by 14%–26% and increased dough water absorption by 3%–7%. By increasing pulse flours, we demonstrate a marked improvement in the nutritional quality of bread. It is imperative to identify lectin null cultivars because baking bread is insufficient to completely eliminate active lectins for uncooked pulse flours.