Determination of Diversity of Mold Species and Aflatoxins in Local Traditional Cereal Based Brews Within Nkubu Municipality, Meru County, Kenya

Abstract

Background: Molds produce mycotoxins such as Ochratoxins, Deoxynivalenol, and Aflatoxins which contaminate more than 25% of the global food produced annually. Most traditional brews consumed in Kenya are produced from cereals contaminated with molds and mycotoxins. This poses a public health concern since it exposes consumers to the risk of nephrotoxicity, cancer, teratogenicity and immune-toxicity. However, data on local brew mycotoxin contamination in Nkubu municipality, Meru County remains limited. This study sought to determine the diversity of molds and aflatoxins in cereal based local brews in Nkubu municipality, Meru County, Kenya. 

Methods: A total of sixty-two (62) Marua, seventeen (17) Busaa, and five (5) Chang’aa samples were randomly collected from different brewers in the study area and shipped in sterile containers to the Kenya Methodist University Mycology laboratory for isolation and identification of molds. Molds were isolated using culture method while Aflatoxins were detected using ELISA method.

 Results: Marua brew 62/84 (73.8%) was the most common brew in Nkubu followed by Busaa 17/84 (20.2%), and chang’aa 5/84 (6.0%). Co-occurrence of Aspergillus, Penicillium, and yeast was reported in all the cereal based brews. Aspergillus plus yeast was the most abundant mold species in all the three types of brews: Marua (69.4%), Busaa (70.6%), and Chang’aa (60.0%). The co-existence of molds in Marua and Busaa varied significantly (P<0.001). Busaa had a marginally higher aflatoxin mean concentration, and range (6.40±2.45, [1.12-25.70] ppm) compared to Marua (5.74±3.29, [1.12-25.70] ppm) and chang’aa (2.35±3.07, [1.41-3.55] ppm), though this was not statistically significant (P=0.195). 21/62 (33.9%) and 6/17 (35.3%) of Marua and Busaa samples, respectively had aflatoxin levels > 10 ppb.

Conclusion: Occurrence of molds and Aflatoxins in cereal based brews in Nkubu municipality beyond the tolerable levels recommended by the Kenya Bureau of Standards warrants mycotoxicological quality control of cereal based brews to avoid exposing the consumers to high aflatoxins.