Assessment of Bread in Ogbomoso Metropolis for the Presence of Potassium Bromate

Abstract

Aim: This study is aimed at evaluating the level of potassium bromate in bread in Ogbomoso metropolis. Study Design: This study was made to fit a one way Analysis of Variance (ANOVA). Place and duration of Study: The bread samples were purchased in Ogbomoso metropolis and analyzed in Ibadan, both in Oyo State, Nigeria between July and December, 2018. Methodology: Twenty five loaves of different brands of bread were purchased in Ogbomoso metropolis and transported to Ibadan for analysis. They were analyzed qualitatively and quantitatively for the presence of potassium bromate. The qualitative test was performed directly on a portion of each bread sample using 2 ml of 0.01 M promethazine and 0.6 ml of 12 M hydrochloric acid. The change in colour of each bread sample to purple indicates the presence of potassium bromate. Quantitative determination was done using spectrophotometric method that is based on the redox reaction between bromate and promethazine hydrochloride in an acidic medium. The absorbance of the product was read at 620 nm. Results: Only one out of the 25 bread samples analyzed in this study representing 4.00 % contain potassium bromate under the permissible level. One of the bread samples contains 10.12 µg/g of potassium bromate which is more than 500 times higher than the permissible level. The quantity of KBrO3 in each bread sample correlates with the degree of purple colour obtained in the qualitative test. Conclusion: Since 96.00% of the sampled bread contained potassium bromate in concentrations above safe level for human consumption, bread consumers and bakers are at risk of exposure to potassium bromate with health implications. The need for continuous surveillance and enforcement of the ban on use of potassium bromate in baking industry in Nigeria is recommended.