Abstract

Copper, manganese and zinc have been determinated in 108 samples of bread which reflect the bread consumption in the Netherlands in March 1988. During the period March/April 1989 the bread samples were collected from retail outlets predominantly located in the province of Utrecht. Quality assurance included replicate analyses of copper content in several samples of bread and duplicate analyses of manganese and zinc. Also for quality assurance, the reference materials Brown Bread of BCR (EC/Brussels) and Wheat Flour of NIST/Washington DC (USA) were assayed. Results demonstrate that the data collected are precise and accurate. Mean level for copper in bread (N=108) is 1.74 mg/kg, for manganese 9 mg/kg and for zinc 11 mg/kg. The coppper content of the samples ranges from 0.81 - 5.18 mg/kg, for manganese from 2 - 22 mg/kg and for zinc from 4 - 23 mg/kg. On average, brown bread types contain more copper, manganese and zinc than white bread types do. Copper and zinc levels are twice as high whereas the manganese levels differ by a factor of three for this bread types. Bread consumption in the Netherlands cover, on average, the daily intake of trace elements of males and females aged 22 years and on of copper for 17 - 23%, of manganese for 30 - 45% and of zinc for 15 - 45%.