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茶树[Camellia sinensis (L.) O. Ktze.]起源于中国[1],在中国的西南和华南地区均生长着较多的野生茶树,主要包括横断山脉分布区、滇川黔分布区、滇桂黔分布区和南岭山脉分布区[2]。野生茶树种质遗传多样性丰富[3]、优异种质资源多[4],远离化学农药和城市污染,所制茶产品特色鲜明、品质优异[5-6],已受到消费者喜爱并在市场上热销[7],具有很大的消费潜力。探究野生茶树制茶品质对新产品开发和促进茶产业健康可持续发展具有重要意义,是种质资源合理开发利用的基础。
四川省雷波县地处横断山脉东段,是凉山州的东大门,东南隔江与云南省永善县相望,已被列入国家乡村振兴重点帮扶县。雷波县西宁镇罗山溪乡银厂沟村(28°30′10′′N,103°29′5′′E,海拔1200~1500 m)附近数座山上有约168 hm2的野生茶树及古茶树资源集中分布,其中部分茶树高近10 m,主干直径在10 cm以上的茶树有数百株,以大叶种为主。雷波西宁古茶树与四川大邑野生茶树群体遗传距离最近,其次是荥经野生茶树群体,与云南凤庆野生茶树群体距离最远[8]。周斌等[9]对雷波西宁古茶树的春季新梢主要生化成分进行分析,结果表明其氨基酸质量分数在野生茶树中处于中等水平,儿茶素质量分数较低,咖啡因质量分数较高,具有选育出高咖啡因种质资源的潜力。本研究以栽培的无性系茶树品种和市场上销售的野生茶树红茶产品为对照,从感官审评和生化成分两个方面分析雷波西宁古茶树所制红茶样的品质,旨在为雷波西宁野生古茶树资源的利用、产品开发提供参考。
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感官审评结果如表1所示,栽培型福鼎红茶样外形紧细显金毫,而西宁野生红茶样因其原料芽叶较大且肥厚,其外形重实、紧结、乌润。三个茶样汤色均为橙红色,两个野生茶树汤色更亮,而福鼎红茶样汤色欠明亮,可能与其叶背茸毛较多有关。香气方面,雷波西宁古树红茶的香气特征较突出,为甜香带焦糖香高长,而福鼎红茶样带花香。三种红茶的滋味均为醇味,雷波西宁古树红茶为甜醇鲜,得分最高。综合来看,雷波西宁古树茶制成的红茶感官品质最高,得分为90.4,主要优势体现在香气高,滋味甜醇鲜。
茶样名称
Tea name雷波西宁古树红茶样XNBT 市售野生红茶样CWBT 福鼎红茶样FDBT 评语 Comment 得分 Score 评语 Comment 得分 Score 评语 Comment 得分 Score 外形(25%)
Appearance重实,紧结,乌黑,较润 88.0 灰褐,尚紧结,尚匀整 84.0 红褐显金毫,较紧细,较匀齐 90.0 汤色(10%)
Soup color橙红明亮 91.0 橙红明亮 91.0 橙红欠亮 88.0 香气(25%)
Sweet smell甜香带焦糖香,高长 91.0 较纯,平 86.0 甜香带花香,浓 92.0 滋味(30%)
Taste甜醇鲜 92.0 醇和显酸 85.0 醇厚爽口 89.0 叶底(10%)
Tea residue红亮,柔软,匀 89.0 红褐,尚匀,有梗,较硬 84.0 柔软,有芽,红亮,匀整 93.0 总分(100%)
Total90.4 85.5 90.3 Table 1. Sensory assessment of quality characteristics of black tea
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三种红茶的儿茶素组分如图1a所示,儿茶素总量均低于12 mg·g−1,雷波西宁古树红茶样的总量最高,为11.5 mg·g−1,比市售野生红茶样和福鼎红茶样分别高出40.25%和30.7%。雷波西宁古树红茶样儿茶素组分最多的是EGCG,含量为5.8 mg·g−1,比市售野生红茶样和福鼎红茶样分别高出555.5%和156.5%;其次是ECG,含量为4.3 mg·g−1,仍高出另外两种红茶分别38.7%和65.4%。雷波西宁古树红茶样和福鼎红茶样的儿茶素组分均以酯型儿茶素为主,占儿茶素总量的100%和95.5%,而市售野生红茶样的酯型儿茶素占64.6%。
Figure 1. Contents of catechin component (a), tea pigment component (b) and caffeine (c) in the three black tea samples (mg·g −1)
三种红茶的主要色素含量如图1b所示,均表现为TBs>TRs>TFs。雷波西宁古树红茶样的色素总量低于市售野生红茶样,高于福鼎红茶样,为131.9 mg·g−1。雷波西宁古树红茶样的咖啡因含量最高,为48.7 mg·g−1,比市售野生红茶样高出80.4%(见图1c)。
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如表2所示,共检测出20种氨基酸组分,雷波西宁古树红茶样的氨基酸总量最高,为19.89 mg·g−1,比市售野生红茶样高出25.3%。雷波西宁古树红茶样的The总量占比值仅21.3%,市售红茶样和福鼎红茶样的The占比较高,分别为42.6%和39.7%。雷波西宁红茶样有13种氨基酸的含量同时高于另外两种红茶样,分别为Asp、Thr、Asn、Glu、Gln、Gly、Ala、Val、Leu、g-ABA、Lys、His和Arg。其中雷波西宁古树红茶样的Gln含量比市售红茶样高出754.2%,比福鼎红茶样高出485.7%,Leu、Asp、Thr和Ile分别比市售野生红茶样高出146.4%、117.4%、100%和100%。
样品名称
Sample name雷波西宁古树红
茶样XNBT市售野生红
茶样CWBT福鼎红茶
样FDBT天冬氨酸Asp 1.50 0.69 1.12 苏氨酸Thr 0.60 0.30 0.28 丝氨酸Ser 0.77 0.49 0.90 天冬酰胺Asn 2.88 2.03 2.54 谷氨酸Glu 1.50 0.76 1.22 谷氨酰胺Gln 2.05 0.24 0.35 茶氨酸The 4.23 6.76 7.80 甘氨酸Gly 0.03 0.02 0.02 丙氨酸Ala 0.34 0.33 0.28 缬氨酸Val 0.93 0.63 0.86 半胱氨酸Cys 0.01 0.01 ND 甲硫氨酸Met ND ND ND 异亮氨酸Ile 0.46 0.23 0.47 亮氨酸Leu 0.69 0.28 0.50 酪氨酸Tyr 0.30 0.31 0.39 苯丙氨酸Phe 0.66 0.55 0.71 γ-氨基丁酸g-ABA 0.57 0.45 0.22 赖氨酸Lys 0.53 0.30 0.52 组氨酸His 0.13 0.08 0.06 精氨酸Arg 1.23 1.04 0.80 脯氨酸Pro 0.48 0.37 0.59 氨基酸总量 19.89 15.87 19.63 注:ND表示低于最低检测限。
Note: ND means lower than the minimum detection limit.Table 2. Content and total amount of free amino acids in the three black tea samples (mg·g−1)
Sensory Quality Evaluation and Biochemical Composition Analysis of Black Tea Made from Xi’ning Ancient Tea Trees in Leibo County
doi: 10.12172/202112010003
- Received Date: 2021-12-01
- Available Online: 2022-07-19
- Publish Date: 2022-10-26
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Key words:
- Leibo Xining ancient tea trees /
- Black tea /
- Sensory quality /
- Biochemical composition
Abstract: In order to explore the tea production potential of wild ancient tea trees in Xi’ning town, Leibo county and promote the development and utilization of germplasm resources, the sensory quality evaluation and biochemical composition determination of black tea samples made from the wild ancient tea trees in Xi’ning (referred to as XNBT for short) were carried out, and compared with other black tea samples. The results showed that: (1) XNBT was heavy and firm in appearance, orange-red and bright in soup color, long-lasting sweet with caramel in aroma, sweet, mellow and fresh in taste, and red and soft in phyllotaxis. The sensory evaluation score of XNBT was 90.4, which was slightly higher than that of the black tea made from the spring tips of the clonal tea variety ‘Fuding Dabai’ (90.3, referred to as FDBT) and a commercially available wild-plant black tea in the market (85.5, referred to as CWBT). (2) The total catechin content of XNBT was 11.5 mg·g−1, which was 40.2% and 30.7% higher than that of CWBT and FDBT, respectively. The caffeine content (48.7 mg·g−1) and total free amino acid content (19.89 mg·g−1) of XNBT were slightly higher than those of the other two black teas. The main tea pigments (thearubigen, theaflavin and theafucin) of XNBT black tea were 131.90 mg·g−1, which was higher than that of FDBT but lower than that of CWBT. In summary, the quality of XNBT was superior and it was valuable for development and utilization. Its quality formation may be related to the biological characteristics of wild tea population and the climate of Leibo. It is recommended to strengthen the protection and utilization of this resource.