The article uses dried pitaya and four types of teas-jasmine tea, black tea, oolong tea, and white tea-as raw materials to blend four red-colored flavored tea blends. The blending ratios were 0.8 g dried pitaya and 1 g of jasmine tea; 0.6 g dried pitaya and 1g black tea; 0.6 g dried pitaya and 1.25 g oolong tea; and 0.45 g dried pitaya and 1.25 g white tea, respectively. Sensory evaluation found that piataya-jasmine tea exhibited a rich and lasting floral fragrance with a bright light rose-red liquor, and a fresh and strong taste; pitaya-black tea had a lasting honey-like aroma, bright orange-red color, and a sweet, mellow taste; pitaya oolong tea offered a lasting floral-sweet aroma, light-red and bright color, and mellow sweetness; pitaya white tea showed a fragrant and lasting aroma, a light rose-red and bright color, and a sweet and mellow taste. It was found that the adding pitaya reduced catechins and caffeine contents, increased the content of free amino acids, lowered tea bitterness, making the flavored tea more appealing to younger consumers.

To study the quality changes of Jinggu Big White Tea during storage over different years,samples aged from 1 to 7 years were collected. Sensory evaluation, biochemical component analysis, and taste activity value (TAV) calculation were conducted to assess quality variations. The sensory evaluation revealed that with prolonged storage, the aroma of the tea shifted from floral and sweet to a stale aroma, with samples aged over five year being dominated by stale aromas. The taste also transformed from fresh and sweet to mellow. With increasing aging years, the content of certain compounds such as gallic acid, ellagic acid, rutin, myricetin, quercetin, and luteolin increased significantly; while most amino acids and catechin decreased, and the level of caffeine and certain amino acids such as phenylalanine fluctuated. Additionally, seven characteristic components with TAV＞1 were identified, including caffeine, epicatechin gallate, and epigallocatechin gallate responsible for bitterness, and epigallocatechin, epigallocatechin gallate, epicatechin gallate, and gallic acid responsbile for astringency. This study clarified the variations in sensory quality and characteristic taste compounds of Jinggu Big White Tea at different storage years, providing a foundation for systematic analysis of its aging mechanism.

Fresh leaves with one bud and two leaves of Yangta Da Bai tea in Jinggu County were processed into Moonlight White Tea using two withering methods and three drying methods. Sensory evaluation, analysis of characteristic components, and aroma substances were conducted to optimize the processing technology of Jinggu White Tea. Sensory evaluation revealed that white tea produced through compound withering and 50 ℃ hot-air drying exhibited a pekoe aroma with floral notes, a sweet and mellow taste with a lasting aftertaste, and uniformly tender yellow-green leaves. The content of 11 amino acids, soluble sugars, ellagic acid, epicatechin, and gallic acid were significantly higher in samples processed by this method than in other samples. In contrast, the content of catechin gallate, epigallocatechin gallate, epigallocatechin gallate, theophylline, quercetin, myricetin, kaempferol, and catechin were lower than those in other samples. A total of 187 volatile compounds were identified in the optimized samples using GC-MS, mainly including terpenes, esters, alcohols, aldehydes, and heterocyclic compounds. Calculations have found that 20 compounds had odor activity values (OAV) ＞ 1, including: terpinenes (OAV = 411.86), imparting fresh and lemon-like aromas; linalool (OAV = 20.48), contributing sweet and floral notes; and sotolon (OAV = 208.18), associated with sweet aromas, all significantly contributing to the floral and sweet aroma profile. This study optimized the processing technology of Jinggu Moonlight White Tea and provided experimental evidence for the standardized processing of Jinggu Da Bai Tea.

In this study, Debaryomyces hansenii PETY002, isolated from Pu-erh tea, was used for enhanced fermentation (EF) of Pu-erh tea. The total number of yeast colonies was significantly higher in the EF group than in the natural fermentation (NF) group. Sensory evaluation revealed that the tea infusion from the EF group was darker in color, mellower in taste, and had a mushroom-like aroma. Compared with NF, EF showed an increase in the contents of theabrownins and water extracts and a decrease in the contents of tea polyphenols, catechins including catechin (C), epigallocatechin (EGC), gallocatechin (GC) and epigallocahechin-3-gallate (EGCG), and caffeine. On the other hand, there was little difference in the contents of flavonoids or amino acids. Microbial community analysis revealed that Debaryomyces was the dominant fungus in EF. Furthermore, there was a competitive interaction between Debaryomyces and Thermomyces. Correlation analysis revealed that Debaryomyces were positively correlated with theabrownins, but negatively correlated with soluble sugars and theaflavins. In conclusion, inoculation with D. hansenii PETY002 changed the diversity and composition of the microbial community during Pu-erh tea fermentation, which improved the quality of Pu-erh tea through interactions with other dominant microorganisms.