Impact of baking on vitamin E content of pseudocereals amaranth, quinoa, and buckwheat

The aim of this study was to analyze the vitamin E composition of amaranth, quinoa, and buckwheat pseudocereals. The method used consisted of a one-step extraction with hexane followed by normal-phase high-performance liquid chromatography (NP-HPLC) coupled with a fluorescence detector. This method afforded complete separation of all vitamin E compounds present. In addition, vitamin E stability following high-temperature processing such as breadmaking was also studied. The vitamin E composition differed significantly from grain type to grain type, and highest vitamin E content (expressed as α-tocopherol equivalents) was found in quinoa grains, followed by amaranth and buckwheat (24.7, 15.4, and 6.3 μg/g respectively). None of the pseudocereal grains contained tocotrienols, which were only detected in wheat grains in minor quantities. Vitamin E recovery following breadbaking was high (70-93%) and gluten-free breads containing pseudocereal had significantly higher vitamin E content compared with the gluten-free control. Amaranth, quinoa, and buckwheat grains proved to be good sources of vitamin E and may be used as ingredients in gluten-free products for improving vitamin E content and thus overall nutritional quality.