六安瓜片拉老火“起霜”的形成机制及其对茶叶品质的影响

采用图像扫描技术,结合成对偏爱检验法、茶叶感官审评法以及茶叶理化成分检测,探索了六安瓜片的起霜条件、霜与茶叶品质的相关性,并通过纸片代替茶叶,收集瓜片起霜过程中的“霜”,探索了瓜片霜的化学本质。试验结果表明,拉老火起霜过程中的摩擦因子是起霜的关键;拉老火工艺不仅改善了瓜片的外形,同时对其香气和滋味也产生了有利的影响。成对偏爱试验结果亦表明,评价员更偏爱拉老火起霜的瓜片。经LC-MS和GC-MS初步鉴定,“霜”的化学物质非常复杂,主要由咖啡碱、儿茶素类、黄酮苷类以及萜烯类等多种非挥发性物质和多种挥发性物质组成。

The Mechanism of Frost-like Powder and Its Effects on Lu′anguapian Tea Quality

The precondition of frost-like powder formation of Lu′anguapian tea and the correlation between frost-like powder and tea quality were explored by image technologies, paired preference test and traditional sensory evaluation. To identify the chemical properties of the white frost-like powder, filter paper was used to replace the tea leaves to collect white frost-like powder from the surface of the leaves during the process. The results showed that friction was the key factor for the formation of the frost-like powder. The technologies called “Lalaohuo” could not only improve the appearance of tea but also affect its flavor and taste. Based on LC-MS and GC-MS analysis, the main chemicals of white frost-like powder were very complicated, which included caffeine, catechins, flavonoid glycosides and volatiles such as terpenes.