不同烘焙程度‘春闺’闽北乌龙茶风味品质分析

Analysis of Flavor Quality of‘Chungui’Minbei Oolong Tea with Different Baking Degrees

采用感官审评、生化分析、超高效液相色谱三重四极杆串联质谱(UPLC-QqQ-MS)及顶空固相微萃取法结合气相色谱-飞行时间质谱联用技术(HS-SPME-GC-TOF-MS)对不同烘焙程度‘春闺’闽北乌龙茶进行检测分析,通过建立偏最小二乘判别分析模型、趋势模型探究其感官品质、常规生化成分、儿茶素组分、氨基酸组分及挥发性物质等方面的差异。结果表明:轻火‘春闺’感官审评总分为(91.3~93.65),略低于中火‘春闺’(93.6~94.15);生化成分中,轻火‘春闺’的氨基酸含量显著高于中火(P<0.05),中火‘春闺’的的茶黄素、茶褐素含量及酚氨比显著高于轻火火‘春闺’(P<0.05);对氨基酸组分进行TAV值计算得到,轻火‘春闺’主要呈味贡献氨基酸为半胱氨酸、天冬氨酸、谷氨酸及茶氨酸,中火‘春闺’为半胱氨酸、谷氨酸及茶氨酸;在主要差异挥发性物质中,轻火‘春闺’的橙花叔醇、吲哚、α-法尼烯及顺-茉莉酮等花香类挥发性物质含量显著高于中火‘春闺’(P<0.05);中火‘春闺’的顺-芳樟醇氧化物、茶吡咯、2,5-二甲基吡嗪、糠醛、脱氢-β-紫罗兰酮及二氢猕猴桃内酯含量显著高于轻火‘春闺’(P<0.05)。‘春闺’闽北乌龙茶适合采用中火烘焙工艺,其滋味醇爽浓厚有花香,香气类型呈现为花香馥郁,综合品质较优。本研究为‘春闺’闽北乌龙茶配套加工工艺和风味品质提供一定的理论依据。

Sensory evaluation,biochemical analysis,ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry(UPLC-QqQ-MS)and headspace solid-phase microextraction combined with gas chromatography-time-of-flight mass spectrometry(HS-SPME-GC-TOF-MS)were used to detect and analyze different baking degrees of‘Chungui’Minbei oolong tea.Partial least squares discriminant analysis model and trend model were established to explore the differences in sensory quality,conventional biochemical components,catechin components,amino acid components and volatile substances.The results showed that the total score of sensory evaluation of light baking degree of‘Chungui’(91.3~93.65)was slightly lower than that of medium baking degree(93.6~94.15).Among the biochemical components, the amino acid content of light baking degree was significantly higher than that of medium baking degree (P<0.05), and the content of theaflavin, theabrownin and the ratio of phenol to ammonia in medium baking degree were significantly higher than those in light (P<0.05). The TAV values of amino acid components were calculated, and the main amino acids contributing to the taste of light baking degree of ‘Chungui’ were cysteine, aspartic acid, glutamic acid and theanine, while those of medium baking degree were cysteine, glutamic acid and theanine. Among the main differential volatile substances, the contents of volatile substances such as nerolidol, indole, α-farnesene and cis-jasmone in the light baking degree of ‘Chungui’ were significantly higher than those in the medium baking degree (P<0.05). The contents of cis-linalool oxide, tea pyrrole, 2,5-dimethyl pyrazine, furfural, dehydro-β-ionone and dihydroactinidiolide in the medium baking degree of ‘Chungui’ were significantly higher than those in the light baking degree of ‘Chungui’ (P<0.05). ‘Chungui’ Minbei oolong tea was suitable for medium fire baking process. Its taste was mellow, strong and floral, and the aroma type was floral fragrance, and the comprehensive quality was better. This study would provide a theoretical basis for the supporting processing technology and flavor quality of ‘Chungui’ Minbei oolong tea.