Abstract: The precondition of frost-like powder formation of Lu′anguapian tea and the correlation between frost-like powder and tea quality were explored by image technologies, paired preference test and traditional sensory evaluation. To identify the chemical properties of the white frost-like powder, filter paper was used to replace the tea leaves to collect white frost-like powder from the surface of the leaves during the process. The results showed that friction was the key factor for the formation of the frost-like powder. The technologies called “Lalaohuo” could not only improve the appearance of tea but also affect its flavor and taste. Based on LC-MS and GC-MS analysis, the main chemicals of white frost-like powder were very complicated, which included caffeine, catechins, flavonoid glycosides and volatiles such as terpenes.

Key words: green tea, Lu'anguapian tea, Lalaohuo, frostliking powder, tea quality