Determination of aflatoxin B1 in selected powdered spices from Kampala local markets

Abstract

Aflatoxin contamination in food commodities poses a significant global health challenge, particularly in regions with warm and humid climates. This study investigated the incidence of aflatoxin-producing molds and the levels of Aflatoxin B1 in commonly consumed spices (chili, ginger, and garlic) sourced from three major markets in Kampala, Uganda: Kalerwe, Nakasero, and Owiino. A total of three samples for each spice type were collected from each market. Detection of the presence of Aspergillus flavus and Aspergillus parasiticus fungi was done using the culture-based method, while Aflatoxin B1 concentrations were quantified using the Attenuated Total Reflectance – Fourier Transform Infrared Spectroscopy (ATR-FTIR) methods. Results indicated a concerning prevalence of aflatoxin-producing molds across the spice samples. Ginger exhibited the highest susceptibility to mold contamination, with 6 out of 9 total samples testing positive. Correspondingly, quantitative analysis revealed that ginger also presented the highest levels of Aflatoxin B1 contamination, with a substantial 66.7% of its samples exceeding the 10 µg/kg regulatory threshold. Chili and garlic also showed significant contamination, with 44.4% and 33.3% of their respective samples exceeding 10 µg/kg Aflatoxin B1. Notably, Aflatoxin B1 was detected in some samples even in the absence of viable mold, indicating the persistence of the toxin post-mold inactivation. These findings highlight a substantial public health risk to consumers exposed to contaminated spices, particularly ginger, in the local markets. The study underscores an urgent need for enhanced food safety interventions, including improved post-harvest handling, storage practices, and rigorous enforcement of Aflatoxin B1 limits by regulatory bodies. Such measures are crucial for safeguarding public health and ensuring the quality of the spice supply chain in Uganda.