Microbial Stability and Sensory Persistence of an Enriched Cereal-Legume-Plantain Flour Blend During Ambient Storage: Implications for Food Security

Authors: Alilu Jabiru Daddy, Usman, G.O.

Abstract: This study investigated the ambient storage stability of a novel composite flour blend formulated from toasted yellow maize (Zea mays), Bambara groundnut (Vigna subterranea), and firm ripe plantain (Musa paradisiaca). The research aimed to determine the safe shelf-life and consumer acceptability persistence of the product under conditions typical of resource-constrained settings. Six flour blends, ranging from 100% maize (control) to a 50:50 ratio of maize and a Bambara/plantain composite, were packaged in polyethylene bags and stored at 28±2°C for eight weeks. Microbiological quality (total mold and coliform counts) and sensory attributes (appearance, aroma, mouth feel, consistency, and overall acceptability) were evaluated bi-weekly. Results indicated that coliform counts remained negligible (<10² cfu/g) throughout the storage period, confirming good hygienic production. Total mold counts, however, showed a time-dependent increase, remaining within the acceptable safety limit of ≤1×10⁴ cfu/g for up to six weeks before exceeding this threshold in subsequent weeks. Sensory evaluation revealed a gradual decline in all hedonic scores over time. Despite this, the fortified blends, particularly those with 40% and 50% composite flour (AJD5 and AJD6), maintained significantly higher acceptability scores, ending the storage period at "liked slightly" to "liked moderately" levels (5.90-6.50 on a 7-point scale). The control sample exhibited a more rapid decline in sensory quality. The study concludes that the enriched cereal-legume-plantain flour blend maintains microbiological safety for six weeks and acceptable sensory quality for at least eight weeks under ambient storage. This extended shelf-life, coupled with sustained consumer preference for fortified blends, underscores the product's practical utility and potential to enhance food security by providing a stable, nutritious, and acceptable food base in environments without refrigeration.