不同光质萎凋对贡眉白茶滋味品质的影响

为筛选改善贡眉白茶滋味的最优萎凋光质,采用LED精量调制光源,通过感官审评法、超高效液相色谱串联三重四级杆质谱、高效液相色谱等方法,研究无光(对照)、日光、蓝光、黄光和红光萎凋,对贡眉白茶的感官品质、主要生化成分、部分代谢物的影响。结果表明,4个光照组感官审评的滋味、香气及总得分,均比无光组高,且红光滋味得分最高。相比无光和其他光质组,红光组的可溶性糖、水浸出物、咖啡碱、没食子儿茶素没食子酸酯、茶氨酸、苏氨酸、谷氨酸、谷氨酰氨、甘氨酸、丙氨酸、γ-氨基丁酸及总氨基酸的含量最高,有益于“醇厚鲜甜”的滋味特征形成。相比无光组,4个光照组显著降低部分黄酮(醇)苷的含量(P<0.05),红光组的茶黄素和茶黄素-3-没食子酸酯的含量显著降低(P<0.05),而黄、蓝、白光组的山奈酚含量显著升高(P<0.05)。综合认为,红光萎凋对白茶滋味提高最有益。

Effects of different light quality on the taste and quality of Gongmei white tea during withering process

To screen the withering light quality that is most beneficial to improve the taste of Gongmei white tea,LED precision modulation light source of five light quality treatments(dark,sunlight,blue,yellow,red)were carried out to investigate their effects on the sensory quality,main biochemical components,and some metabolites of Gongmei white tea.Sensory evaluation method,ultra high-performance liquid chromatography-tandem triple quadrupole mass spectrometry(UPLC-QQQ-MS),high performance liquid chromatography(HPLC)and other methods were adopted.The results showed that taste,aroma and total scores of the sensory evaluation of the 4 light treatment were higher than control group,and the taste score of red light was the highest.Compared with the other light quality treatments,the Gongmei white tea with red light treatment had the highest soluble sugars,water extracts,caffeine,epigallocatechin gallate(EGCG),theanine,threonine,glutamic acid,glutamylamine,glycine,alanine,γ-aminobutyric acid and the total content of amino acids,which were beneficial to taste characteristics of"mellow,fresh and sweet".Besides,the Gongmei white teas of the 4 light treatments significantly reduced the content of some flavonoids(alcohol)glycosides(P<0.05),and the content of theaflavins and theaflavin-3-gallate in the red light treatments were significantly reduced(P<0.05).Moreover,the content of kaempferol in the yellow,blue and white light treatments were significantly increased(P<0.05).It is generally believed that red light withering is the best for improving the taste of Gongmei white tea.