RESUMEN
Crush-tear-curl (CTC) black tea is a popular beverage, owing to its unique taste characteristics and health benefits. However, differences in the taste quality and chemical profiles of CTC black tea from different geographical regions remain unclear. In this study, 28 CTC black tea samples were collected from six geographical regions and analyzed using electronic tongue and ultrahigh performance liquid chromatography-Orbitrap-mass spectroscopy. The e-tongue analysis indicated that each region's CTC black tea has its own relatively prominent taste characteristics: Sri Lanka (more umami and astringent), North India (more umami), China (more sweetness and astringent), South India (moderate umami and sweetness), and Kenya (moderate umami and astringent). Based on multivariate statistical analysis, 78 metabolites were tentatively identified and used as potential markers for CTC black tea of different origins, mainly including amino acids, flavone/flavonol glycosides, and pigments. Different metabolites, which contributed to the taste characteristics of CTC black tea, were clarified by partial least squares regression correlation analysis. Our findings may serve as useful references for future studies on origin traceability and quality characteristic determination of CTC black teas. PRACTICAL APPLICATION: This study provides useful references for future studies on the origin traceability and taste characteristic determination of CTC black teas from different geographical regions.
Asunto(s)
Camellia sinensis , Cromatografía Líquida de Alta Presión , Análisis de los Alimentos , Espectrometría de Masas , Aminoácidos/análisis , Camellia sinensis/química , Camellia sinensis/clasificación , Análisis de los Alimentos/métodos , Glicósidos/análisis , Extractos Vegetales/químicaRESUMEN
OBJECTIVE: To set up the fittest medium and optimum condition for plantlets to form microtubers. METHOD: Plant hormones, concentration of sucrose, active carbon and light time influenced formation of adventitious root and microtuber in vitro from plantlet of Rehmannia glutinosa (85-5). RESULT AND CONCLUSION: The plantlets were cultivated on the medium of microtuber induction after roots were induced on the 1/2MS medium with IBA 1 mg.L-1. The best medium was MS + 6-BA 2 mg.L-1 + NAA 0.1 mg.L-1 + Sucrose 5%. The fittest incubation temperature was 25 degrees C and the light length was (2,000-3,000 lx) 12 h.d-1. Active carbon and GA3 should not be added to the medium, which was not suitable for the induction of microtuber.