The nutritional composition of Norwegian white wheat flour (78% extraction)

The purpose of the present project was to supply new, representative data for the nutritional composition of white wheat flour (78% extraction), henceforth called wheat flour, in the continuous task to update the Norwegian Food Composition Table and database.

Each year a varying percentage of imported wheat is added to the wheat grown in Norway to enhance the quality of the flour. In the present project, the wheat flour was sampled as ready for purchase, i.e. the flour consisted of a mix of Norwegian and imported wheat. Eleven samples of wheat flour based on the Norwegian 2003 crop and 10 samples of wheat flour based on the Norwegian 2004 crop were analyzed for relevant nutrients. Flour samples from the two largest Norwegian milling companies, Norgesmøllene and Cerealia, were included in the project. Both milling companies receive wheat from mills from different parts of the country and make flour for household use (household flour) and flour for use by bakeries and the food industry (industrial flour). For key nutrients, household flour and industrial flour were sampled separately to be able to identify possible differences in the nutritional composition between the two types of flour.

The majority of the analyses were performed at the National Institute of Nutrition and Seafood Research’s laboratory in Bergen, Norway. However, analysis of starch, dietary fiber, and sugars were performed by a subcontractor.

Generally, only small differences were seen between the nutrient content of household flour and industrial flour, between flour based on the 2003 crop and flour based on the 2004 crop, and between flour from mills in different parts of the country. The flour samples based on the 2004 crop had a lower water content than the samples based on the 2003 crop, while the starch content was higher in the samples based on the 2004 crop.

The analytical results from the various mills, milling companies, and flour types were combined according to market shares at the beginning of the project. For the majority of nutrients, a mean value between the flour based on the 2003 and 2004 crop was calculated for future inclusion in the food composition table. As no explanation was found with respect to the somewhat deviant analytical results for water and starch in the 2004 crop, these values were not used when compiling the table values.

New analytical values from the present analytical project will be included in the Norwegian food composition database and replace the present values for wheat flour in the Norwegian Food Composition Table at the next update.