Taste expression and stability of L-theanine in strong-flavor Baijiu

In this study, applying electronic tongue detection combined with sensory evaluation, the taste expression was analyzed by adding L-theanine 0, 0.04%, 0.06%, 0.08%, 0.10%, 0.16%, and 1.00%, respectively to strong-flavor (Nongxiangxing) Baijiu with alcohol content 42%vol, adding L-theanine 0.08% in ethanol solutions with different volume fractions (0, 2%, 12%, 22%, 32%, 42%, 52%) and L-theanine 0.08% to the 42%vol strong-flavor Baijiu at different drinking temperatures (5 ℃, 15 ℃, 25 ℃). The strong-flavor Baijiu with L-theanine 0.04%, 0.08% and 0.10% were stored at room temperature for 13 months, 16 months, 19 months and 22 months to investigate the stability of L-theanine in Baijiu. The results showed that when the addition of L-theanine in the 42%vol strong-flavor Baijiu was higher than 0.08%, it had significant umami flavor. With the increased addition of L-theanine in the strong-flavor Baijiu, it had a certain strengthening effect on the expression of sourness, sweetness and saltiness in Baijiu, but had no significant influence on the expression of bitterness. When the volume fraction of ethanol was between 0-22%, the taste expression of L-theanine did not change significantly. When the volume fraction of ethanol was between 42%-52%, the umami and salty taste of L-theanine increased significantly, while the sour taste was inhibited. With the extension of storage time, the content of L-theanine in the strong-flavor Baijiu first decreased significantly and then tended to stabilize, with the maximum reduction reaching 42.36%, and there was no sediment in the liquor body. This research laid the foundation for the development and application of L-theanine in strong-flavor Baijiu.