Folates in quinoa (Chenopodium quinoa), amaranth (Amaranthus sp.) and buckwheat (Fagopyrum esculentum): Influence of cooking and malting

Abstract

Effects of processing on the contents of five folate vitamers in quinoa, amaranth and buckwheat were analysed using a trienzymatic extraction method followed by LC–MS/MS. Total folate (TF) content, corresponding to the sum of folic acid (FA), 5-methyltetrahydrofolate (5-MTHF) and 10-formyltetrahydrofolate (10-CHOTHF) expressed as folic acid equivalent, in raw quinoa, amaranth and buckwheat were 309 ± 8.07, 228 ± 24.2 and 153 ± 12.4 μg/100 g dw, respectively, being dominantly 5-MTHF. Boiling and steaming reduced the TF in amaranth by 58% and 22%, respectively, whereas up to a 10–15% increase was observed in quinoa. Boiling and steaming did not significantly alter the TF content in buckwheat although significant changes were observed in some individual folate vitamers. Malting, on the other hand significantly increased TF content in amaranth by 21% (276 ± 14.2 μg/100 g dw) and buckwheat by 27% (193 ± 20.0 μg/100 g dw), whereas no significant change in quinoa was observed. Based on the EFSA recommendations, a portion of amaranth and quinoa (either boiled, steamed or malted) may contribute up to more than 25% of the dietary reference value for folates, whereas buckwheat may contribute only 14% when cooked and 19% when malted. Results demonstrate that quinoa, amaranth and buckwheat are good sources of folates, regardless of processing.The scientific work was funded by the Portuguese Fundação para a Ciência e a Tecnologia (FCT) under the scope of the strategic project UID/EMS/00667/2013. The analytical work has been financially supported by Project ELEMENTARIA funded by the Instituto Nacional de Saúde Doutor Ricardo Jorge, I.P. Lisbon, Portugal (2013DAN850) and PRO-METROFOOD project, funded by European Union’s Horizon 2020 research and innovation programme under grant agreement No 739568.info:eu-repo/semantics/publishedVersio