[Determination of folates in food. Comparative and critical study]

A study on the microbiologic method for folate determination in natural products was carried out. The variables that must be considered were analyzed previous to the application of this technique, that is: nature of combinations of the compounds with vitamin activity, function and distribution of the conjugases, capacity of absorption of the polyglutamates present in foods, natural inhibitors of the conjugases and the importance of the selection of the microorganism used. Based on the preliminary investigations a modified microbiological microtechnique is proposed and its importance for some nutricional aspects is discussed.