Evaluation of aluminum contents in different bakery foods by electrothermal atomic absorption spectrometer

The present study provides the dietary intake of a non-essential metal, aluminum (Al), in bakery products consumed in the urban areas of Hyderabad, Pakistan. The contribution of the different bakery products to the daily intake of Al was also evaluated. Samples of different branded and non-branded bread and biscuits studied using electrothermal atomic absorption spectrometry (ETAAS) prior to microwave assisted and conventional wet acid digestion methods. Results were calculated in mg/kg. The validity and accuracy of both procedures were checked by using certified sample of beech leaves (BCR 100). Non-significant differences were observed for P>0.05 when comparing the values obtained by both methods (paired t-test). The mean Al concentration of each branded and non-branded biscuit samples were found in the range of 7.4–84.3 and 34.5–70.2 mg/kg, respectively, while the analysis of branded and non-branded bread revealed the presence of Al at concentration levels from 8.0 to 29.6 and 39.1 to 82.9 mg/kg, respectively. We observed that the levels of Al were significantly higher in non-branded bread, biscuit and in some branded products. The contribution of the bakery products to the daily intake of Al, based on the consumption of 250 g bread or biscuit per day, was found in the range of 1.9–21.1, 8.62–17.6, 2.0–7.4, and 9.5–20.7 mg/day, from all branded and non-branded biscuit and bread, respectively. The limit of detection (LOD) and limit of quantitation (LOQ) of Al were 0.5 and 5 μg/L, respectively.