Li-Hong Tan,Dan Zhang,Gang Wang,Bao Yu,Sheng-Ping Zhao,Jian-Wei Wang,Ling Yao,Wei-Guo Cao
The aim of this study was to compare the flavonoids compositions, content and antioxidant activities of Hawk tea from six botanical origins for screening the most suitable botanical origins. The main flavonoids of Hawk teas from Litsea coreana Levl. var. lanuginose were identified, and six high contents of individual flavonoids (hyperin, isoquercitrin, quercitrin, astragalin, quercetin and kaempferol) were quantitative and comparative analysis. Moreover the potential antioxidant capacity of Hawk tea was measured by using in vitro antioxidant assays. The above experimental data were all used for the principal component analysis. The statistical results showed that the extracts from Machilus chuanchienensis S. Lee and L. coreana Levl. var. lanuginose appeared closely positioned in the positive regions, indicated the higher flavonoids and antioxidant activity compared with other species. Thus, they were temporarily considered as good sources of Hawk tea.
Dark hawk tea, produced through pile-fermentation of Lauraceae family leaves, which is rich in various beneficial ingredients and health functions, relies heavily on microbial activity for its unique characteristics. However, the processing technology of dark hawk tea and the microorganisms' dynamic changes during its pile-fermentation remain largely unknown. In this study, based on the previous work, we optimized pile-fermentation parameters for analyzing changes in dark hawk tea's chemical components, volatile substances, and microbial diversity. The tea exhibited superior sensory scores and biochemical qualities under optimal conditions (35 °C, 62% water, 24 h), measuring 5.7 mg/g amino acid content. Gas chromatography-mass spectrometry (GC-MS) identified 108 volatile compounds, notably terpenes, ketones, and esters. Microbial analysis revealed Bacteroides and Faecalibacterium as dominant bacteria and Cladosporium and Mortierella as dominant fungi. Cladosporium prevailed in early fermentation, shifting to Mortierella later. Predicted metabolic pathways highlighted microbial functional genes predominantly participated in carbohydrate, amino acid, and energy metabolism during the pile-fermentation. These results hold important implications for expanding the variety of hawk tea products and deepening our understanding of microbial community dynamics through the pile-fermentation of dark hawk tea.
危险品化学品经营许可证（带存储）