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

摘要

Vitamin E composition of amaranth, quinoa and buckwheat were analysed. The method used consisted of a 1-step extraction with hexane followed by normal-phase HPLC coupled with a fluorescence detector. This method afforded complete separation of all vitamin E compounds present. In addition, vitamin E stability following high-temp. processing such as breadmaking was also studied. Vitamin E composition differed significantly from grain type to grain type, and highest vitamin E content (expressed as alpha-tocopherol equivalents) was found in quinoa grains, followed by amaranth and buckwheat (24.7, 15.4 and 6.3 mug/g respectively). None of the pseudocereal grains contained tocotrienols, which were only detected in wheat grains in minor quantities. Vitamin E recovery following bread baking was high (70-93%) and gluten-free breads containing pseudocereals 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 it is suggested that they may be used as ingredients in gluten-free products for improving vitamin E content and thus overall nutritional quality.