Application of Functional Microorganisms in Seed-Based Fermentation for the Production of Nutritionally Enhanced and Bioactive Food Condiments: A Review

Fermentation remains one of the oldest and most effective biotechnological processes for improving food quality, safety, and shelf life. In Africa, the fermentation of seed-based substrates such as African locust bean ( Parkia biglobosa ), soybean ( Glycine max ), melon seed ( Citrullus lanatus ), Bambara groundnut ( Vigna subterranea ), and sesame ( Sesamum indicum ) plays a vital role in the production of traditional condiments, such as iru , dawadawa , ogiri , ugba , and okpehe. This review examines the application of functional microorganisms in the fermentation of seed-based substrates and their contributions to the enhancement of nutritional and bioactive properties of fermented food condiments. Functional microorganisms, including lactic acid bacteria, Bacillus species, yeasts, and selected fungi, facilitate complex biochemical transformations through enzymatic degradation of proteins, carbohydrates, and lipids. These activities improve nutrient bioavailability, protein digestibility, flavor development, and overall product quality. An ideal functional starter culture must possess several criteria that include safety status, enzymatic capability, acid tolerance, fermentation efficiency, and bioactive metabolite production, are discussed. The review highlights the mechanisms through which microbial fermentation promotes the production of bioactive compounds such as bioactive peptides, bacteriocins, short-chain fatty acids, gamma-aminobutyric acids, and antioxidant metabolites, many of which are associated with antihypertensive, antimicrobial, antioxidant, and gut-health-promoting effects. In addition, fermentation significantly reduces antinutritional factors such as phytates, tannins, oxalates, and trypsin inhibitors, thus enhancing mineral absorption and nutritional utilization. Overall, the integration of functional microorganisms into seed-based fermentation systems offers a sustainable approach to improving the nutritional value, safety, functionality, and commercial potential of traditional fermented condiments. This approach supports food security, promotes the valorization of indigenous seed resources, and contributes to the development of innovative functional foods aligned with modern nutritional and public health needs.