【作者】 王丽丽；

【导师】 夏会龙；

【作者基本信息】 浙江工商大学 ， 食品科学， 2008， 硕士

【摘要】 茶树花具有花期长、开花量大和芳香清甜的特点,资源丰富,具有极高的开发利用价值,适于花饮料、化妆品等多种行业开发利用。因此有必要对茶树花香气成分进行系统全面的研究,为茶树花的开发利用提供理论依据。本研究在确定的SDE优化提取参数(加入消泡剂,蒸馏提取时间60min、料液比10 g干花/500 mL水)的条件下,结合GC、GC-MS分析方法,研究了不同开放状态的鸠坑种新鲜茶树花的主要香气成分、8个不同品种茶树花精油在组成上的共性、特性,不同干燥方式对茶树花香气成分含量的影响以及常温储存下干茶树花香气成分的变化,以较全面的揭示茶树花的香气特征。研究发现:1、新鲜初展茶树花香气成分主要为芳香醇类、萜烯醇类、脂肪醇类和芳香酮类化合物,这几类物质占精油总含量的84.1～95.6%。其含量较高的香气成分根据对其香型的贡献分为两类:一类为给茶树花带来青气的化合物,包括2-戊醇(2.6～23.9%)、2-庚醇(1.1～8.3%)、青叶醇(0.4～3.0%)、3-戊醇(0.1～4.0%)、1-戊烯-3-醇(0.1～3.2%)、2-己醇(0.2～1.6%)等;另一类为给茶树花带来清甜花香(或果香)的化合物,包括苯乙酮(14.7～65.2%)、芳樟醇(1.8～24.0%)、α-苯乙醇(2.6～13.1%)、2-苯乙醇(0.5～8.3%)、香叶醇(0.2～3.8%)、水杨酸甲酯(0.1～3.2%)等。其中苯乙酮、α-苯乙醇、2-戊醇、2-苯乙醇、芳樟醇为茶树花的主要香气成分。2、花蕾、初展、全展三种开放状态的鸠坑种茶树花的主要香气成分相似,但其含量差异较大。就精油总含量来说,初展态为311.78ug/g,全展态为273.44 ug/g,两者间差异较小,均远高于花蕾的112.33ug/g。花蕾香气成分中,具有青气的2-戊醇、2-庚醇等脂肪醇类相对含量百分比较高,而具花香的苯乙酮等物质相对含量百分比较低。随着开花的进展,芳香醇类、醛类、酮类等化合物不断释放出来,特别是苯乙酮和α-苯乙醇在花蕾到初展期间含量急剧增加,在初展态达到最大,随后含量缓慢减少。这两种物质含量占精油总含量的50%左右。3、对浙农139、浙农21、宜兴种、信阳种、梅占、大红袍、瑞安白毛茶、浙农117等8个茶树品种的初展花精油的研究结果表明,品种间的主要香气成分相似,因此茶树花主体香型不因其品种而变化,而香气特征因其香气成分比例的不同而有所差别。8个品种茶树花精油总含量相差较大,由高到低依次是:浙农21＞宜兴种＞梅占＞浙农139＞信阳种＞浙农117＞瑞安白毛茶＞大红袍。其中浙农21和宜兴种的精油总含量远高于其它6个品种。除瑞安白毛茶外,其他7个品种茶树花精油中苯乙酮含量均为最高,其中浙农21和宜兴种茶树花中苯乙酮含量高达396.38μg/g和382.75μg/g,高于其他6个品种的精油总含量。4、将鸠坑种茶树花进行阴干、烘干和冷冻干燥处理后,香气成分和含量有明显的变化。与冷藏相比,三种干燥处理的茶树花主要香气成分相似,含有较高的苯乙酮、α-苯乙醇、2-苯乙醇、芳樟醇以及2-戊醇等,仍具有茶树花的特征香型。其精油总含量都有不同程度的减少,由大到小排列为:冷藏＞冻干＞阴干＞烘干。经干燥处理,大部分香气化合物的含量都有明显的减少,特别是苯乙酮损失显著。另外,一些低沸点、不稳定香气物质如3-戊醇、2-戊醇、1-戊烯-3-醇、2-己醇、青叶醛、2-庚醇、(Z)-2-戊烯-1-醇、2-戊烯、正己醇等明显减少。而部分芳香族醇类、醛类和萜烯醇类化合物的含量却有了不同程度的增加,特别是2-苯乙醇增加显著。5、对茶树干花在常温下分别储存20天、80天后,其香气成分变化明显,精油总含量与大部分香气成分的含量都随着存放时间的延长而明显下降。低沸点香气物质含量下降率尤为明显,特别是几种含量较高的成分如糠醛、2-丁醇、2-戊醇、3-羟基-2-丁酮等,储存80天后,这些成分含量极微甚至不能检出。而较高沸点成分如苯乙酮、芳樟醇氧化物等成分的含量下降率较小,芳樟醇、α-紫罗兰酮、β-紫罗兰酮、2-苯乙醇、苯甲醇等成分的含量反而有升高的趋势。构成茶树花香型的主要香气成分苯乙酮、2-苯乙醇、α-苯乙醇和芳樟醇,其相对百分含量随储存时间的延长而呈明显的增长趋势。由此可见,常温存放虽然对茶树花精油总含量影响较大,但并不影响其主体香型,其特征香气甚至更加明显。更多还原

【Abstract】 Tea (Camellia sinensis) flower, with a fresh sweet floral aroma, has long florescence and large yield. Promising utilization of tea flower for some business such as to be used for beverage and cosmetic products, makes it necessary to do a systematic and complete research on tea flower.The extract method of tea flower was studied, the optimization condition was : 10 g dried flower added into 500 mL water with 0.5 Ml defoamer in round bottom flask for boiling 60 min. SDE was used to collect the aroma components of tea flower. The components of tea flower were analyzed and identified with GC and GC-MS. The main aroma components of fresh tea flower of Jiukang c.var in different blooming stages, the aroma characteristics of those flowers from eight cultivars, concentration of aroma components of tea flower dried by different methods were studied. The results were as following: 1 The main aroma components of bursting tea flower were aliphatic alcohols, aromatic alcohols, terpenols, and aromatic ketons, accounting for 84.1—95.6% of the essential oil. These could be classified into two types according to the concentration to the flavor types. One includes the components with weedy or grassy aroma, including 2-pentanol, 2-heptanol, (Z)-3-hexen-1-ol, 3-pentanol, 1-penten-3-ol, 2-hexanol, etc. The other includes the components with sweet floral aroma, including acetophenone, linalool, alpha-methyl-benzenemethanol, phenylethyl alcohol, methyl salicylate, etc. acetophenone and alpha-methyl-benzenemethanol were characteristic flavor compounds.2 The volatile profiles in the essential oils from tea flower of cultivar Jiukang in different blooming stages were similar. The essential oil of the early blooming and full blooming stages was similar and both were far higher than that of flower bud. In the aroma compounds of flower bud, the relative proportion of aliphatic alcohols, such as 2-pentanol, 2-hepeanol, was high. With the flowering process going on, aromatic alcohols, ketons, and aldehydes compounds released continuously. But the content of acetophenone and alpha-methyl- benzenemethanol, accounting for 50% of essential oil, sharply increased during the blooming stage.3 The main volatile profiles in the essential oils from tea flower from eight cultivars were similar. Therefore, the main flavor type was not changed while the aroma characteristics were different because of different aroma profiles. The order of the concentration of reducing essential oil was Zhenong 21 > Yixing > Meizhan > Zhenong 139 > Xinyang > Zhenong117 > Ruian > Dahongpao. The essential oil concentration of Zhenong21 and Yixing were much higher than the others. Acetophenone of the other seven cultivars except for Ruian is highest in concentration.4 The volatile profiles in the essential oils from tea flower dried by frozen, freeze-drying, oven-drying, and shadow-drying were different. Compared with the frozen flower, there were similar aroma components and similar main compound in the essential oil of flower by drying treatment. The order of the concentration of s reducing essential oil was frozen > freeze-drying > shadow-drying > oven-drying. The concentration of most aroma components decreased, especially for acetophenone. Essential oil concentration of Zhenong21 and Yixing were much higher than the others. Acetophenone of the other severn cultivars except for Ruian is the highest in concentration. Compounds with lower boiling point decreased significantly, while some aromatic alcohols, aldehydes, and terpenols increased in different degrees, and phenylethyl alcohol increased significantly.5 The aroma profiles were significantly changed and the concentration of essential oil and most aroma components decreased after tea flower was stored for 20 d and 80 d. The concentration of compounds with lower boiling point decreased significantly, while compounds with higher boiling point, such as acetophenone and linalool oxides, decreased slowly and linalool, beta-ionone, phenylethyl alcohol, and benzyl alcohol increased. The relative proportion of the main aroma components increased significantly. Therefore, the aroma type of the tea flower was not changed with the storage time.更多还原