[Quality of data on folic acid content in vegetables included in several Spanish Food Composition Tables and new data on their folate content].

The relationship between adequate folate intake, adequate serum levels, and lowering the risk of suffering from cardiovascular diseases, neural tube defects, neural illness and some kind of cancers have been widely studied. Because of the expected health benefits, the consumption of foods with high folate content or enriched foods is increasing. Therefore, an adequate folate intake is important in order to reach acceptable serum levels. Reliable food composition data are necessary in order to evaluate and estimate the populations folate intake, elaborate diets and formulate recommended dietary intakes. For this reason, we revised folic acid data in Spanish Food Composition Tables (FCT). The quality of the data was evaluated and compared with other well-known international Food Composition Tables as well as with a high-resolution liquid chromatographic method (HPLC) validated in our laboratory. We evaluated all data about folate content, as well as all the information given like data origin, analytical method, sampling or original database. For the HPLC method, the food samples were incubated with hog kidney conjugase. After that, the samples were purified and concentrated by strong anion exchange (SAX), then the folate content was quantified by HPLC with a combination of two ultraviolet and fluorescence detectors. The evaluation and comparison of data was established according to some parameters, which define the quality of data, giving punctuation depending on the compliance with these parameters. The study of different sources showed that nutrients were different in definition, analysis method, units and expression of data, and that this fact could have a potential influence on TCA data values. In addition, it has been possible to show a wide variation in food number, name of these foods as well as the analysis of raw or cooked products with different composition. When the quality conditions were tested, the Spanish FCT had the lowest punctuation in folate content data. That is because the Spanish FCT did not use a validated method to quantify folic acid in foods (Direct method of FCT elaboration), but they used folate content data from others FCT (Indirect method of FCT elaboration). These data manifest the importance of getting a consensus method to determine folate content in foods with the aim to obtain a FCT with reliable folate data.