BACTERIOLOGICAL PROFILE OF SOYMILK SOLD IN EKOSODIN IN UNIBEN NIGERIA

Soy milk, sometimes referred to as soybean milk, a staple of the Asian diet is a plant-based beverage made by crushing, boiling, and soaking soybeans, the leftovers are then filtered to create a smooth liquid. However, because of its affordability, growing awareness of its health advantages, and improved public acceptance particularly among those who wish to reduce their intake of animal products its consumption ratio has been rising in other areas. It is also a component of other goods such dressing, soy cheese, and soy yoghurt. Among those who are lactose intolerant or allergic to cow’s milk proteins, it is one of the most popular dairy substitutes consumed globally. Soymilk samples were collected from five major locations; Boundary, Newton, Edo Street, JB, and Backgate and analyzed using standard microbiological methods for total heterotrophic and coliform counts, as well as for the isolation and identification of bacterial species. The total bacterial counts ranged from 1.095 × 10⁷ to 9.5 × 10⁷ CFU/ml, while total coliform counts ranged from 1.0 × 10⁶ to 2.3 × 10⁷ CFU/ml, indicating a high microbial load exceeding recommended limits for ready-to-drink beverages. Three bacterial species were consistently isolated across all samples: Bacillus subtilis, Staphylococcus epidermidis, and Klebsiella pneumoniae. Antimicrobial testing showed that chitosan exhibited broad-spectrum antibacterial activity, with inhibition zones ranging from 21 mm to 50.5 mm. Klebsiella pneumoniae was the most susceptible (MIC = 6.25 µg/ml; MBC = 12.5 µg/ml), while Bacillus subtilis showed the least sensitivity (MIC = 12.5 µg/ml; MBC = 25 µg/ml). These findings reveal significant microbial contamination of locally sold soymilk due to poor hygiene and handling practices and demonstrate the potential of chitosan as a natural biopreservative to enhance the microbial safety and shelf life of soy-based beverages. The study emphasizes the need for Good Manufacturing Practices (GMP) and Hazard Analysis and Critical Control Points (HACCP) systems among local soymilk producers to safeguard public health.