| The temperature of the second firing is the key point in the process for roasted green tea. The research focused on the effect of the temperature of the second firing on the popular quality of Hakka traditional roasted green
tea. Primary tea as the raw material was made by Meizhan, and the biochemical components were analyzed of roasted green
tea after processed by three different temperatures of the second firing. The results showed that the four components
contents, tea polyphenols, caffeine, catechins and ester-catechins, had declined with the rising temperature. Soluble sugar
and free amino acids contents increased and lately declined. Soluble sugar contents significantly increased to 4.31%, when
the temperature reached 115, and then reduced. While free amino acid contents significantly decreased to 2.74% at
115, and the contents increased significantly to 4.00% at 125. The content, EGCG and GC, significantly increased,
with the second firing temperature increasing, while C, GCG, CG decreased. When the temperature reached 125益, 7
catechin ingredients, such as EGCG, GCG, CG, CG, ECG, EGC and EC, were not notably changed, only C had a significant
increase. For primary tea, coupled with the second firing temperature rising, the smell of grass disappeared, sweetness
increased with strong taste. The made tea had an unpleasant flavor and loss of fresh and heavy at 125. So when the
primary teas are fired for three hours at 115 , the made tea has the best quality, and catechin quality index being the
maximum. |
