Physicochemical and Microbiological Profile of Soybean (Glycine max)-based Soumbara as an Emerging Food Condiment in Côte d'Ivoire

Abstract

Background: Soumbara is a traditional West African fermented condiment commonly produced from néré (Parkia biglobosa) seeds. Declining availability and increasing cost of néré seeds have encouraged the use of soybean (Glycine max) as an alternative raw material. However, soybean-based soumbara remains poorly characterised in Côte d’Ivoire, particularly regarding its production practices, consumer awareness, physicochemical properties, and microbiological quality. This limited evidence constrains assessment of its potential for wider food and commercial valorisation. Aims: To characterise the production process, consumption patterns, and physicochemical and microbiological quality of soybean-based soumbara marketed in five communes of Abidjan, Côte d'Ivoire. Study Design: A descriptive study combining direct on-site monitoring of the production process, a consumer survey, and laboratory analysis (physicochemical and microbiological) of market samples. Place and Duration of Study: Five communes (sites) of Abidjan, Côte d'Ivoire, between September and November 2025. Methodology: Production was monitored directly at three processing sites and involved dry roasting, dehulling, potash-assisted boiling, 48 h wrapped fermentation at 25–30 °C, hand-shaping, and two-stage drying. Consumption habits were assessed through a three-stage cluster survey administered to 500 respondents. Thirty soumbara samples (six per commune) were collected across the five communes and analysed for pH, titratable acidity, refractometric dry extract, moisture, dry matter, and microbial loads (total aerobic mesophilic bacteria, Staphylococcus spp., Bacillus spores, yeasts and moulds, total and faecal coliforms, Escherichia coli, sulfite-reducing anaerobes, and Salmonella). Results: Among the 500 respondents, 449 (89.8%) consumed soumbara of either type. Néré-based soumbara was known by 91.3% of respondents, versus only 8.0% for soybean-based soumbara, with a similar pattern of consumption across communes. Soybean-based soumbara was consumed mainly in grain (ball) form, once per month; 52.9% of consumers spent 50–200 FCFA per purchase, with commune-level rates ranging from 39% to 62%. Physicochemical analysis showed a near-neutral pH (6.48–6.70), inversely related to titratable acidity (0.52–0.66%); moisture ranged from 6.44% to 14.56% and dry matter from 85.44% to 93.56%, with significant variation among communes (p < 0.05). Total aerobic mesophilic bacteria (mean 7.04 ± 0.26 log10 CFU/g) and Staphylococcus spp. (mean 6.11 ± 0.33 log10 CFU/g) exceeded acceptability thresholds in every sample, while Bacillus spores, yeasts and moulds (where detected) remained within expected ranges. Total and faecal coliforms, E. coli, sulfite-reducing anaerobes, and Salmonella were absent from all samples. Conclusion: Soybean-based soumbara remains a nutritionally promising but little-known condiment in Abidjan. Its microbiological quality does not yet meet acceptability criteria for total aerobic mesophilic bacteria and staphylococci, despite the absence of enteric pathogens. Improved hygienic practices during production and marketing are needed before this product can be confidently promoted as a safe valorisation strategy for West African fermented condiments.