Abstract:

In order to optimize the preparation processing of En Seven sweet Gynostemma pentaphyllum tea, the optimal preparation parameters including Shaqing temperature, time, material-liquid ratio and cooling time after Shaqing were investigated. The optimal processing conditions were temperature at 100 ℃, Shaqing time of 2 min, and cooling down time on stainless wire bed of 5 min. In addition, 15 min of piling up was necessary before drying of prepared tea products. The optimal drying conditions were drying at 100 ℃for 4 h. These optimal preparation and drying conditions could result in a high retention rate of bioactive components, less loss of nutrients, superior color and taste, and stable quality of prepared tea products. The optimal brewing conditions were soaking tea products in hot water at 80 ℃ for 45 min with the material-liquid ratio of 1: 50. Under the optimal brewing condition, the bioactive and nutritional components in tea products can be dissolved in water to provide health functions. These investigations will provide a theoretical reference for future depth development of Gynostemma pentaphyllum tea.

Key words: En Seven sweet Gynostemma pentaphyllum, dragon beard tea, preparation processing, optimization