节点文献
康砖茶渥堆微生物及不同渥堆处理品质成分变化的研究
Study on the Microorganism during Pile-fermentation and the Change of Quality Contents under Different Conditions of Pile-fermentation to the Kangzhuan Tea
【作者】 付润华;
【导师】 齐桂年;
【作者基本信息】 四川农业大学 , 茶学, 2008, 硕士
【摘要】 四川南路边茶是我国特有的一大茶叶种类,有着非常厚重的历史内涵和文化底蕴,南路边茶是藏族同胞的生活必需品。渥堆被认为是形成黑茶特有品质的关键工序,目的是促使粗老的鲜叶原料通过一定程度的渥堆,形成滋味醇和、香气纯正、汤色黄红明亮的品质特征。关于渥堆中化学变化的促使因子及其与黑茶品质形成的关系,大多数观点认为主要是微生物的作用。在渥堆过程中,产生大量的微生物,并在其代谢过程中或其代谢过程中释放的胞外酶的作用下,使内含物成分发生转化、降解等,从而形成黑茶特殊的品质。四川康砖已有上千年的生产历史,但对四川康砖的微生物的研究很少见有报道,因此,研究康砖茶渥堆微生物及不同渥堆处理品质变化对提高康砖品质和工艺改进具有重要意义。本文以康砖茶为材料,根据菌株形态和生理生化,初步分离、鉴定渥堆中的微生物,筛选出优势菌种,再以传统生产渥堆、实验室模拟渥堆、无菌渥堆和优势菌接种到无菌原料中进行渥堆。实验结果如下:1.康砖茶渥堆中的细菌为:第一种菌体为杆状,直或接近直,菌落乳白色或黄色,圆形、扁平,中等或小,表面光滑,不透明,革兰氏染色阳性,部分产芽孢,芽孢椭圆形,严格好氧或兼性厌氧等,初步鉴定为芽孢杆菌属(Bacillus sp.);第二种菌体为球状,单个或成对排列,菌落淡黄色,圆形、扁平,中等,表面光滑,不透明,革兰氏染色阳性,耐高温,兼性厌氧,初步鉴定为葡萄球菌属(Staphylococcus)。2.康砖茶渥堆中的酵母菌为:菌体为卵圆或椭圆,边缘完整,光亮、粘稠、易挑取,菌落为乳白或奶白色,较大,表面光滑,表面平,不透明,革兰氏染色阳性,有的有假菌丝,兼性厌氧等,初步鉴定为假丝酵母属(Candida sp.)。3.康砖茶渥堆中的霉菌为:第一种菌落平坦,卵圆或椭圆,较大,质地为丝绒状,表面呈黑色,有隔膜,有的有孢子囊,菌落反面是黄褐色,初步鉴定为黑曲霉属(Aspergillus niger);第二种为圆形或椭圆,较大,质地为毯状,青绿色,菌落背面为墨绿色,有的有孢子囊,大多有分节孢子等,初步鉴定为青霉属(Penicillium sp.);第三种为圆形或椭圆,较大,质地为毯状,灰绿色,背面呈乳黄色或橙褐色,需氧等,初步鉴定为灰绿曲霉属(Aspergillus glaucus);第四种为圆形或椭圆,较大,质地为毛绒状,灰白色,有的有孢子囊,耐高温,需氧等,初步鉴定为毛霉属(Mucor)。4.在对微生物初步分离、鉴定后,数量较多,对渥堆过程具有优良性状的微生物即为优势菌。四川康砖渥堆的优势菌为芽孢杆菌属(Bacillus sp.)、假丝酵母属(Candida sp.)、黑曲霉属(Aspergillus niger)、青霉属(Penicillium sp.)。5.康砖茶四种不同渥堆处理的温度变化为:传统生产渥堆、模拟渥堆和接种渥堆处理都是先上升,再回升,在120h到最大值,无菌渥堆先缓慢上升,再缓慢下降:水分变化为:传统生产渥堆、模拟渥堆和接种渥堆处理都在24h前下降,在24~96h相对平稳,96h后缓慢上升,无菌渥堆则一直下降;水浸出物含量变化为:传统生产渥堆、模拟渥堆和接种渥堆处理在48h前上升,48h达最大值,48~72h下降,72~120h基本平稳,120h后下降,无菌渥堆在48h达到最大值,之后一直下降;茶多酚含量变化为:四种不同渥堆处理均一直缓慢下降;氨基酸含量变化为:传统生产渥堆、模拟渥堆和接种渥堆处理先下降,后上升,在120h达到最低;无菌渥堆先下降,再上升,144h达最低;咖啡碱含量在四种不同渥堆处理整个渥堆过程中波动起伏,各渥堆时期含量无明显差异;总糖含量变化为:传统生产渥堆、模拟渥堆和接种渥堆处理24h前下降,24~48h上升,48~96h急剧下降,96~120h上升,再下降:无菌渥堆24h前先上升,再下降;儿茶素含量变化为:四种不同渥堆处理均一直缓慢下降;pH值在传统生产渥堆、模拟渥堆和优势菌接种渥堆处理一直下降,无菌渥堆则变化不大。
【Abstract】 The Sichuan south—road brick tea is a unique type of tea in our country, and it has the massive historical connotation and the cultural deposits. It was still the Tibetan compatriots necessities of life. Pile-fermentation was considered the pivotal process which forms the unique quality of the brick tea. The purpose is to promote the tough fresh leaf of raw material through a certain degree of fermentation, then it forms the characteristic of mellow-taste, pure aroma, and bright red color. What is the promotive factor of chemical change during pile-fermentation and the relations which to form with the brick tea quality? The majority viewpoints thought mainly reason of that is the function of microorganism. In the process of pile-fermentation, it produced a large number of microbes and under the function which in the course of their metabolism or the lyoenzyme which released of it, caused the inclusion ingredient to have the transformation, the degeneration and so on, thus formed the special quality of the brick tea. Sichuan KangZhuan Tea has had over a thousand year production histories, but the research of microorganisms to Sichuan KangZhuan Tea are rarely seen. Therefore, the study on the microorganisms during pile-fermentation and the change of quality under different conditions of pile-fermentation has vital significance in enhancing the quality and the process improvement of the Sichuan KangZhuan Tea.In this article, the author took the Sichuan KangZhuan Tea for the material of study, and the study is finished by following steps: primary separated and identified the microorganism of pile-fermentation according to the patterns and physiogical-biochemical characteristic of bacterial strain, filtered the preponderant strain, then piled-fermentation under traditional production conditions, laboratory simulation conditions, aseptic conditions and inoculated the advantages of vaccination to aseptic material in the pile-fermentation. The experimental results were as follows:1. The bacterium during pile-fermentation to the KangZhuan Tea: the first is the rod-shaped bacteria, straight or close to straight, the colony milky white or yellow, round, flat, medium or small, smooth surface, opaque, gram-positive staining, some produced Bacillus, Bacillusoval and of strictly anaerobic or aerobic, identified as Bacillus. Spherical for the second thalli, individual or paired with, the colony pale yellow, round, flat, medium , the surface smooth, opaque, Gram stain positive, high temperatures, and ofamphoteric anaerobic, identified as Staphylococcus.2. The microzyme during pile-fermentation to the KangZhuan Tea: the cell for the oval or ellipse, marginal integrity, bright, thick, easy to pick from, colony for creamy white or milk white, large, smooth surface, opaque, the surface is even, not transparent, Gram stain positive, some of them had the pseudo mycelium, some of them were false mycelium, anaerobic, identified as a Candida for the rayon yeast.3. The mildew during pile-fermentation to the KangZhuan Tea : the first kind is colony flat, oval or ellipse, a bit larger, and velvet-like texture.It surface is black and have septum.Some of them have sporangium, and the oppostite of it is brown, identified as Black Aspergillums Niger; The second kind is round or oval, larger, for the blanket-like texture, turquoise, the colony back to green black, and some had sporangium, most had arthrosporeand so on, are identified as Penicillium; The third kind is round or oval, larger, for the blanket-like texture, gray green, the back of a milk or orange yellow brown, aerobic, identified as Aspergillus glaucus; For the fourth round or oval, larger, for the plush-like texture, off-white, and some had sporangium, abled to endure high temperatures, aerobic, identified as Mucor.4. After the initial isolation, identification of Microorganisms, the quantity is large. The microorganisms with excellent reactor traits became the dominant microorganism. The dominant microorganism during pile-fermentation to the Sichuan KangZhuan Tea was: Bacillus, Candida, Aspergillus, Penicillium.5.The change of temperature under four different conditions of pile-fermenation to the Kangzhuan Tea: Piled-fermentation under traditional production conditions, laboratory simulation conditions, inoculated in the pile-fermentation were rise first, then picked-up in the 120h to the maximum; Piled-fermentation under aseptic conditions first was rise slowly, then declined slowly. The change of water content : Piled-fermentation under traditional production conditions, laboratory simulation conditions, inoculated in the pile-fermentation all to decline before 24h , were relatively stable in the 24-96h . after 96h also rise slowly , while aseptic conditions had been declining; The change of water extraction contents: Piled-fermentation under traditional production conditions, laboratory simulation conditions, inoculated in the pile-fermentation rise before 48h , in the 48h to the maximum, 48~72h decreased, were relatively stable in the 72-120h, dropped after120h , aseptic conditions in the 48h to the maximum, followed had been declining; The change of tea polyphenoi contents: piled-fermentation under four different conditions had been declined slowly; The change of amino acid contents: Piled-fermentation under traditional production conditions, laboratory simulation conditions, inoculated in the pile-fermentation declined, after rising , 120h met the minimum; aseptic conditions started to drop and was rise, 144h to a minimum; The change of caffeine content in the whole process of piled-fermentation under four different conditions was fluctuant, and had no significant difference in the each period of piled-fermentation. The change of total sugar contents: Piled-fermentation under traditional production conditions, laboratory simulation conditions, inoculated in the pile-fermentation declined before 24h, 24~48h rise, 48-96h declined sharp, 96-120h increased, then decreased, aseptic conditions piled up before 24h, and then declined. The change of catechin content: piled-fermentation under four different conditions had been declined slowly; The change of pH value: Piled-fermentation under traditional production conditions, laboratory simulation conditions, inoculated in the pile-fermentation had been declining, aseptic conditions was no big change. Four pile-fermentation deal with the general trends were: inoculated in the piled-fermentation was the biggest, piled-fermentation under aseptic conditions was the lest. It was the most important to KangZhuan was the function of microorganism.