The certification of major components and major elements in five food reference materials

Summary The development of five food reference materials (whole milk powder, pork muscle, rye and wheat flour, and haricot beans) is described. Homogeneity and stability of three categories of nutrients, major components, major elements and vitamins, proved to be adequate. Certification of Kjeldahl nitrogen, total fat, lactose, total dietary fibre (AOAC method), ash, Na, K, Mg, Ca, and Cl contents was successful. In contrast, only indicative values could be given for starch and sugars, nonstarch polysaccharides and P because of insufficient agreement between laboratories. The measurement of these components and elements need further study to obtain the improvement needed. Indicative values for retinol, -carotene, -tocopherol, vitamin B₁, vitamin C, and niacin in some of these materials could be given. Prospects for future certification of vitamins are favourable.