【作者】 姚路畅；

【导师】 李华；

【作者基本信息】 西北农林科技大学 ， 葡萄与葡萄酒学， 2008， 硕士

【摘要】 好葡萄酒是“种出来的”,葡萄酒质量的高低完全取决于它的原料。“在原料质量良好的情况下,尽可能地将存在于原料中的所有潜在质量在葡萄酒中经济、完美地表现出来;在原料质量较差的情况下,则应尽量掩盖和除去其缺陷,生产出质量相对良好的葡萄酒”,这是葡萄酒酿造学研究的重要问题。葡萄酒的特有成分主要存在于果皮和果肉细胞中。果皮由于富含葡萄酒的特殊成分,则被认为是葡萄浆果的“高贵”部分。葡萄果皮的下表皮细胞中积累有芳香物质、色素和单宁,这些物质含量的高低在很大程度上决定着葡萄酒的质量。因此对这些有益成分的提取是现代葡萄酒工艺学研究的重点。传统工艺采用“CO2浸渍”、“常温浸渍”、“热浸渍”等方法提取葡萄果皮中的有益成分,但这些方法会改变原料的性质及降低葡萄酒的质量。本研究以霞多丽(Chardonnay)葡萄浆果为材料,分别在-15℃、-20℃、-25℃、-30℃、-32℃五种不同温度下冷冻处理浆果,未处理作对照。通过电子显微镜观察了浆果果皮细胞的破坏情况;在-20℃和常温下,以霞多丽(Chardonnay)葡萄浆果为材料进行小容器酿酒试验,分别对葡萄汁及葡萄酒的理化指标及感官指标进行分析。另外,在-3℃、室温下经过不同时间的浸渍比较了浸渍对浆果果皮中有益物质的提取效果。所有研究结果如下:1.在透射电子显微镜下,未经冷冻处理的浆果果皮细胞,具有完整细胞壁、液泡饱满且细胞质分布均匀,液泡膜等膜系统完好。冷冻温度处理后,细胞都有不同程度的破坏,在-15℃、-20℃时,细胞变形,结构遭到破坏,细胞壁断裂,细胞质浓缩成团;在-25℃、-30℃、-32℃时大量细胞破坏严重,细胞质外泄,细胞严重变形,很难见到完整细胞。2.利用小容器酿造法分别对-20℃冷冻处理和未处理的霞多丽(Chardonnay)浆果进行酿酒试验,对葡萄汁及葡萄酒的理化指标分析表明:冷冻处理后的葡萄汁及葡萄酒中单宁、总酚、总氮及微量元素等物质的含量均明显高于未处理,且香气物质的种类也较多。浆果冷冻处理后酿制的葡萄酒,外观、香气、口感均发生了变化,其果香更为浓郁、平衡,口感更为清爽、干冽。3.通过观察室温浸渍、低温浸渍在不同处理时间下,细胞壁的质壁分离情况,可以发现:随着处理时间的延长,质壁分离现象有加大的趋势,细胞质浓缩成团,结构不容易辨清。更多还原

【Abstract】 The quality of wine depends on raw material. The most important question of enology mainly displays in two aspects. One is to exhibit the potential quality of raw material economically and perfectly as much as possible at good raw materials. The other is to concealment quality defect and make relatively good wine at bad raw materials.The endemic element of wine mainly exist in the cells of pericarp and flesh. There were many special compositions in pericarp, therefore it was regarded as“noblest part”in all parts of grape. The lower epidermis cells were rich in aromatic substance, tannin and pigment. The quality of wine was determined by the contents of these beneficial substances. Thus the emphasis of modern enology is to extract the beneficial substances. In order to extract the beneficial substances of grape, people adopt the traditional methods of“soaking with CO2”,“normal steeping”,“heat steeping”,“cold steeping”. The physicochemical properties of raw material were altered and the quality of wine was reduced by these methods.At five different temperatures: -15℃,-20℃,-25℃,-30℃,-32℃, Freezing effect on the structure of grape pericarp cells was studied using Chardonnay by electron microscope. Wine making experiment was conducted with Chardonnay at -20℃. We studied the physicochemical index and the sensory index of treated juice and wine. The extraction effect of the beneficial substances was studied in different steeping time at -3℃and normal temperature. Aroma components of juice was determined. All results were as followed:1. The untreated berry pericarp cell structure including the cell walls, the vacuoles and the cytoplasm were intact by electron microscope. However, the cells of treated berry were damaged at different degree. At -15℃and -20℃, the cells had been distorted, the structure had been damaged, the cell walls had been fractured. At -25℃, -30℃and -32℃, the most cells of grape berry were damaged badly. The cells had been distorted badly and it was hard to see intact cells.2. Wine making experiment was conducted with Chardonnay at -20℃and unprocessed berry using little vessel. We studied the physicochemical index of treated juice and wine. The content of tannin, total phenols, total nitrogen and trace element were higher than untreated and there was also much more the species of aromatic substance. The appearance, the aroma and the taste of wine which was made by freezed berry had changed. The fruity aroma was much more balanceable and the taste was much more salubrious.3. To investigate the distribution of polyphenol in cell wall at“normal steeping”and“cold steeping”, we could found the phenomenon of the plasmolysis and with the elongation of treatment time, there was an intendance of increase for the phenomenon, and the structure was not resolved easily.更多还原