Analysis on the Difference of Quality and Mineral Elements Among Jinmudan Oolong Tea

Abstract

The sensory evaluation scores, quality indexes (tea polyphenols, caffeine, 8 catechins, soluble sugars, free amino acids, theanine, water extracts and total flavonoids) and 8 mineral elements of different grades of Jinmudan Oolong tea were determined. The results showed that the higher the grade, the higher the water extract content of Jinmudan Oolong tea, and the water extract content of Grand Prize was 1.07% and 1.75% higher than that of first prize and quality prize, respectively, and the differences all reached a significant level (P0.05). The ratio of phenol to ammonia was significantly lower in the grand prize than in the first prize and the quality prize (P0.05). The restricted principal coordinates analysis showed that the quality indexes combined with restricted principal coordinates analysis could well distinguish the grade differences of Jinmudan Oolong tea with an R value of 1.00. However, the mineral elements combined with restricted principal coordinates analysis did not well distinguish the quality differences of different grades of Jinmudan Oolong tea. These results could provide a certain reference for the quality judgment of Jinmudan Oolong tea.

Keywords

• jinmudan oolong tea
• grade difference
• quality index
• mineral elements
• sensory quality
• correlation analysis