加工工艺对枇杷叶茶品质的影响

研究不同加工工艺流程及参数条件对枇杷叶茶品质的影响，为提高枇杷叶茶品质提供技术参考。以新发芽的夏梢枇杷幼叶为材料，杀青后分别采用先揉后炒、先炒后揉再炒和先揉后炒再揉再炒3种工艺流程及不同参数加工枇杷叶茶，对叶茶主要功能成分和冲泡性状指标进行检测，并运用主成分分析和聚类分析法进行综合评价。结果表明，不同工艺流程对枇杷叶茶的品质有较大影响，先揉后炒工艺所制叶茶的总黄酮、茶多酚及总三萜酸的平均含量显著高于先炒后揉再炒工艺，而先炒后揉再炒工艺的可溶性总糖和游离氨基酸含量显著高于先揉后炒工艺，3种工艺下所制枇杷叶茶均具有较强的抗氧化活性。工艺流程、揉捻时间相同条件下，随着炒制时间的延长，茶中总黄酮、茶多酚及总三萜酸含量呈先上升后下降趋势，而游离氨基酸含量大多呈下降趋势。综合主成分分析及感官品质评价，以枇杷新梢幼叶为原料加工叶茶，采用蒸汽杀青75 s、揉捻5 min后再炒制25 min加工的叶茶品质较好。

Effects of Processing Technology on the Quality of Loquat Leaf Tea

The effects of different technological processes and parameters on the quality of loquat leaf tea were studied to provide technical reference for improving the quality of loquat leaf tea.Taking new bud tip of loquat young leaves collected in summer as materials,three processing methods with different processing parameters were adopted to screen optimal one,i.e.,rolling first then stir-frying; stir-frying first then rolling,and stir-frying again; rolling first,then stir-frying,and then rolling again.The chemical constituents and parameters related tea-brewing of the processed products were measured.Principal component analysis and cluster analysis method were used for comprehensive evaluation.The results showed that different processing methods presented significant impacts on the tea quality.The average contents of total flavonoids,polyphenols and total triterpenoid acids of the loquat leaf tea prepared by the method of rolling first and then stir-frying were significantly higher than those prepared by stir-frying first and then rolling.However,the contents of soluble sugar and free amino acids of the tea prepared by stir-frying first and then rolling were significantly higher than those prepared by rolling first and then stir-frying.The teas prepared three methods all exhibited strong antioxidant capacity.Under the same technological process and rolling time,with the extension of stir-frying time,the contents of total flavonoids,polyphenols and total triterpenoid acids basically increased first and then decreased,while the contents of free amino acids mostly decreased.Based on principal component analysis and sensory quality evaluation,the optima processing technology was determined:the leaves were steamed for 75 s,rolled for 5 min and then stir-fried for 25 min.