Volatile and non-volatile compounds profiling and their role in sensory and antioxidative attributes of two species of "red snow tea" (Lethariella)

Lethariella, , a folk herbal tea originating from southwest China, has been consumed for centuries as a traditional beverage. However, the distinct chemical characteristics and sensory properties of Lethariella remain poorly understood. In this study, the two most commonly found Lethariella species, Lethariella zahlbruckneri (LZ) and Lethariella cladonioides (LC), were collected for detailed analysis. After brewing, the infusion of LZ exhibited a taste profile that was more astringent, bitter, and thicker, whereas LC liquor was characterized by a sweeter taste profile, coupled with a stronger lingering sweet aftertaste. This variation in taste between LZ and LC infusions can potentially be ascribed to the higher levels of phenolic compounds present in LZ in comparison to LC, along with the lower content of sugars in LZ. The aroma intensity of LC is more robust, with its relative contents of key volatile compounds being significantly higher compared to those in LZ.