Changes in Components and Improvement of Antioxidant Activity and Allergen Content in Tartary Buckwheat (Fagopyrum tataricum (L.) Gaertn.) Tea by Fermentation

Fermented Tartary buckwheat tea is a beverage prepared by infusing Tartary buckwheat seeds that have been fermented with Aspergillus. This study investigated changes in the components and radical scavenging activity of Tartary buckwheat tea before and after fermentation. Our results indicated that free and peptide forms of amino acids and allergens in tea samples before fermentation decreased by 0.4-, 0.5-, and 0.1-fold after fermentation, respectively. However, the levels of glucose and maltose in tea samples increased by 9.3- and 18.3-fold after fermentation, respectively. Furthermore, the total polyphenol content increased by 1.3-fold with fermentation, which showed a high correlation coefficient with the radical scavenging rate in size-exclusion chromatography. These results indicated that fermentation and roasting caused the Maillard reaction and an enzymatic reaction that affected the changes in the components of Tartary buckwheat tea, which were consequently associated with a reduction in allergens and an increase in radical scavenging activity.