Analysis of Folates
The folate group comprises a wide variety of compounds. Along with the so-called pteroyl monoglutamates folates mainly accur in foods as pteroyl polyglutamates containing two to seven glutamates in their molecule.
Pteroyl monoglutamates also are denominated free folates, which can be determined in foods after extraction without any further enzyme treatment. In contrast, polyglutamates are storage forms and have to be transferred by so-called conjugases to monoglutamates as only the latter can be determined by the majority of methods. Meanwhile many methods are applied and can be devided into three classes: the microbiological and chemical-instrumental ones as well as the binding assays. A particularly accurate method among the chemical-industrial ones is the SIDA.