Chemical and Microbial Safety Assessment of Bambara, Gurasa, and Wara Sold Around Tertiary Institutions in Minna, Niger State, Nigeria

Abstract

Indigenous ready-to-eat snacks, including Bambara (a fried Bambara-starch snack served 
with spiced pepper sauce), gurasa (a baked wheat-flour flatbread consumed with spiced fried 
pepper sauce and ground peanut/groundnut butter), and wara (a fried soybean-curd cheese, 
locally known as soy-wara or awara), are widely consumed by students in tertiary institutions 
in Minna, Niger State, Nigeria. Despite their popularity, limited empirical information exists 
regarding their chemical and microbiological safety within campus food environments. This 
study evaluated the levels of heavy metal contamination (lead, chromium, and cadmium) and 
microbial quality, including total bacterial, coliform, staphylococcal, and fungal counts, in 
these indigenous snacks sold around three tertiary institution communities in Minna. A total 
of ninety samples (30 per snack type; 10 samples per site across three locations) were 
collected and analysed in triplicate. Heavy metal concentrations were determined using 
Atomic Absorption Spectrophotometry (AAS), while microbial loads were quantified using 
the standard pour-plate technique. Lead was detected in 83.3% of Bambara samples (mean 
concentration: 0.144 ± 0.138 mg/L), compared with 26.7% and 40.0% detection frequencies 
in gurasa and wara, respectively. Chromium occurred in up to 93.3% of Bambara samples, 
with the highest mean concentration (1.692 ± 1.912 mg/L) recorded in gurasa. Overall, 18.9% 
of all samples exceeded the indicative lead benchmark of 0.3 mg/L, while 21.1% exceeded 
the indicative chromium benchmark of 2.0 mg/L. Cadmium concentrations remained below 
0.2 mg/L in all samples. Microbiological analysis revealed fungal contamination in 48.9% of 
samples, total bacterial contamination in 32.2%, and Staphylococcus aureus-type colonies in 
25.6%, with wara exhibiting the highest overall contamination rates. The predominant 
bacterial isolates were Staphylococcus aureus (44.4%) and Bacillus subtilis (26.7%), whereas 
Saccharomyces cerevisiae (60.0%), Penicillium spp. (28.9%), and the aflatoxigenic mould 
Aspergillus flavus (8.9%) were the dominant fungal isolates. The findings demonstrate that 
a substantial proportion of indigenous snacks sold around tertiary institutions in Minna pose 
both chemical and microbiological risks capable of compromising student health. The 
observed contamination patterns varied according to snack type and sampling location, 
underscoring the need for routine food safety surveillance, vendor education, strengthened 
hygiene practices, and effective enforcement of food safety regulations within campus food 
environments.