冠突散囊菌LJSC.2001对不同黑毛茶发花品质的影响

Effect of Fermentation by Eurotium cristatum LJSC.2001 on the Fermentation Quality of Raw Dark Tea Made from Different Varieties

为探究冠突散囊菌(Eurotium cristatum)LJSC.2001对不同黑毛茶发花品质的影响,以冠突散囊菌LJSC.2001菌株对湖南安化代表性厂家提供的槠叶齐、云台大叶、桃源大叶黑毛茶原料进行散茶发花,运用感官审评、常规理化成分检测、儿茶素组分高效液相色谱分析、顶空固相微萃取-气相色谱-质谱联用法对其进行滋味、香气品质比较分析。结果表明:不同黑毛茶经冠突散囊菌LJSC.2001发花后,干茶色泽加深、金花满披,汤色变深,菌香浓郁,滋味醇和、醇厚,叶底柔软;白沙溪的黑毛茶原料发花后菌花香浓郁,还保留明显的松烟香;滋味品质成分茶多酚、游离氨基酸、可溶性糖、黄酮、儿茶素总量、杨梅素、槲皮素、山柰酚含量总体呈下降趋势,且云台山和云上的云台大叶黑毛茶发花后儿茶素下降最为显著。挥发性成分分析发现,发花后酯类、醛类增多;不同黑毛茶发花后的挥发性成分含量存在差异,水杨酸甲酯、(E,E)-2,4-庚二烯醛等相对含量较高;多元统计分析发现黑毛茶原料与金花散茶的挥发性成分明显差异,共有19种特征性挥发成分,其中水杨酸甲酯、(E,E)-2,4-庚二烯醛、(E)-芳樟醇3,7-氧化物、(E)-呋喃氧化芳樟、苯乙酮和(E)-2-,(Z)-6-壬二烯醛、(E)-2-己烯醛、(E,E)-3,5-辛二烯-2-酮和正十三烷9种特征挥发性成分含量发花后明显上升,综合形成了金花散茶的菌花香。由此可知,冠突散囊菌LJSC.2001发花能使不同黑毛茶品质滋味更加醇和、醇厚,菌花香凸显。

The current study was performed in order to explore the effect of Eurotium cristatum LJSC.2001 on the fermentation quality of raw dark tea.Golden flower loose tea was produced by using E.cristatum LJSC.2001 to ferment raw dark tea from the cultivars Zhuyeqi,Yuntaidaye and Taoyuandaye provided by representative manufacturers(Yuntaishan,Yunshang,Baishaxi and Junhe)in Anhua,Hunan province,and comparative analysis of their taste and aroma quality was carried out by sensory evaluation,basic physicochemical analysis,analysis of catechin components by high performance liquid chromatography(HPLC),and headspace solid-phase microextraction-gas chromatography-mass spectrometry(HSSPME-GC-MS).Results showed that after fermentation by E.cristatum LJSC.2001,the dry tea samples were darker in color and fully covered with golden flower;their infusions were darker in color,and had a strong fungal aroma and a mellow and full taste,and the brewed tea was soft.Raw dark tea from Baishaxi had a stronger fungal aroma after fermentation,while retaining a distinct pine smoke-like aroma.The contents of taste compounds including tea polyphenols,free amino acids,soluble carbohydrates,flavonoids,total catechins,myricetin,quercetin,and kaempferol showed an overall decreasing trend.The content of catechins in Yuntaidaye raw dark tea from Yuntaishan and Yunshang declined most.The relative contents of esters and aldehydes increased after fermentation.There were differences in the content of volatile components among the different fermented tea samples,methyl salicylate and(E,E)-2,4-heptadienal being the major ones.Multivariate statistical analysis showed significant differences in volatile composition between golden flower loose tea and raw black tea.There were 19 characteristic volatile components identified including methyl salicylate,(E,E)-2,4-heptadienal,(E)-linalool 3,7-oxide,(E)-furan oxidized linaloa,acetophenone,(E)-2-,(Z)-6-nonadienal,(E)-2-hexenal,(E,E)-3,5-octadien-2-one and n-tridecane.The contents of the nine volatile components increased significantly after fermentation,and they all contributed to the fungal aroma of golden flower loose tea.It can be seen that fermentation by E.cristatum LJSC.2001 can impart a more mellow and fuller taste and a more prominent fungal aroma to raw black tea.