不同闷黄工艺对蒙顶黄芽风味品质的影响

The Effect of Different Yellowing Processes on the Flavor Quality of Mengding Yellow Bud

为缩短传统蒙顶黄芽加工时间,提出一种快速闷黄工艺,并结合感官审评、高效液相色谱(high performance liquid chromatography,HPLC)、气相色谱-质谱(gas chromatography-mass spectrometry,GC-MS)等分析方法,探讨不闷黄、传统闷黄、快速闷黄工艺对蒙顶黄芽风味品质的影响。结果表明,2种闷黄工艺的感官审评总分均比不闷黄工艺高,且快速闷黄工艺总分最高。闷黄工艺后,表没食子儿茶素(epigallocatechin,EGC)、儿茶素(catechin,C)、表儿茶素(epicatechin,EC)、咖啡碱、可溶性糖和谷氨酸含量均增加,EGC、可溶性糖和谷氨酸含量增加均达到显著水平(P<0.05);表没食子儿茶素没食子酸酯(epigallocatechin gallate,EGCG)、表儿茶素没食子酸酯(epicatechin gallate,ECG)、儿茶素总量均减少,快速闷黄工艺的EGCG、茶多酚、氨基酸总量、茶氨酸、叶绿素b和叶绿素总量的减少均达到显著水平(P<0.05)。3种工艺样品均鉴定出42种香气成分,其中醇类化合物的种类(9种)和相对含量最高(占香气成分的31.68%~36.20%)。与不闷黄工艺相比,2种闷黄工艺醇类、酮类及其他类香气物质相对含量有所增加,其中快速闷黄工艺的醇类及其他类香气物质相对含量增加幅度更大,而酯类、醛类相对含量有所减少,其中传统闷黄减少幅度更大。

This study proposes a yellowing process to shorten the processing time of traditional Mengding yellow bud.The effects of traditional yellowing,and fast yellowing processes were investigated using sensory evaluation methods,high performance liquid chromatography,gas chromatography-mass spectrometry and other methods.The results revealed that the sensory evaluation scores of the two yellowing treatments were higher than that of non-sealed yellow tea,and the total sensory score of fast yellowing was the highest.After yellowing treatment,the epigallocatechin(EGC),catechin(C),epicatechin,caffeine,soluble sugar and glutamic acid content increased,and the EGC,soluble sugar and glutamic acid content increased significantly(P<0.05).Epigallocatechin gallate(EGCG),epicatechin gallate and total C content decreased.The levels of EGCG,polyphenols,total amino acids,chlorophyll b,and total chlorophyll theanine reached a significant level(P<0.05).Aromatic components(42)were identified in three treatment samples.There were 9 types identified,of which alcohol compounds were the highest(accounting for 31.68%-36.20%of the aromatic components).Compared with the samples of non-sealed yellow tea,the relative content of alcohols,ketones,and other aromatic compounds in the two yellowing treatments increased.The highest increase in the relative content of alcohols and other aromatic substances was observed in the fast yellowing process.The relative content of esters and aldehydes decreased,with the highest decrease observed in the traditional yellowing process.