Accurate Measurement of Vitamins in Foods and Tissues

Abstract

Besides the inorganic constituents, phytate was also determined in the dry material, and was found to contain an initial level of 1.4±0.2 mg/g [3]. The storage stability of this constituent is being investigated. This preliminary investigation has demonstrated the feasibility of exploring a total mixed diet matrix for certification as a multicomponent Standard Reference Material (SRM). A bigger batch of a second mixed total diet is under investigation as part of a systematic study to evaluate the stability of several components over a period of at least 3-5 years. The experience gained from this investigation has helped in understanding some of the practical difficulties faced in the preparation of a natural biological reference matrix for multiple components, especially organic constituents. The authors are thankful to John Jones and Kathleen Cook (FDA) and Robert Watters (NBS) for elemental analysis, Michele Schantz (NBS) for organic analysis, and Eugene Morris (USDA) for phytate analysis.