【作者】 裴广仁；

【导师】 李记明；

【作者基本信息】 烟台大学 ， 农产品加工及贮藏工程， 2010， 硕士

【摘要】 以目前国内生产冰葡萄酒的主要品种威代尔(Vidal)葡萄为试材,于2008-2009年在辽宁桓仁,通过研究:葡萄成熟后期及结冰过程中主要成分的变化,冰酒原料的冷冻方式、不同来源的酵母菌株等关键工艺对冰酒质量的影响,以确定冰葡萄植株的最适埋土期、果实的最佳采收期,论证自然条件下离体冷冻的合理性,筛选适宜于冰葡萄品种及产地特色的冰酒酵母。文章还针对冰酒发酵过程中产生高挥发酸的工艺原因进行了探讨,寻找降低冰酒挥发酸的工艺条件。通过对辽宁桓仁产区的威代尔葡萄成熟过程中糖、酸、重量等指标变化进行跟踪测定,发现,威代尔葡萄(2009年)在11月9日不再生长,葡萄果穗可以进行修剪挂枝操作,葡萄植株可以进行埋土操作。根据试验研究和07~09年的气候资料,提出冰葡萄的埋土操作应以时间和温度作为指标。11月上旬,可以作为冰葡萄藤埋土的时间标准,0℃~10℃作为冰葡萄藤埋土的温度标准。对不同时间(温度)采收获得的冰葡萄原料及所酿冰酒的品质进行系统分析,结果显示:于2008年12月26日、2009年1月3日采收的冰葡萄原料及所酿冰酒均达到加拿大酒商质量联盟(VQA)的要求。根据试验结果和辽宁桓仁近三年(07-09年)的气候资料,提出辽宁桓仁的冰葡萄采收期的确定应以温度和时间作为指标。自12月上旬开始,应关注气温的变化,并根据温度变化确定采收时间,温度范围在-18℃~-6℃之间,采摘的冰葡萄的质量满足VQA标准,且能发酵获得优质冰酒。通过对连体冷冻、自然条件下的离体冷冻和人工冷冻的葡萄、葡萄冷冻汁及其所酿冰酒的主要质量指标和感官质量的比较发现:连体冷冻和离体冷冻的葡萄、葡萄冷冻汁的主要质量指标之间并无显著差异,均达到VQA冰酒原料标准,二者所酿冰酒的理化指标差异也不显著,符合冰酒的VQA标准。离体冷冻可以作为冰酒原料的冷冻方式,其对于拓展冰酒产区具有重要的指导意义。而人工冷冻的冰葡萄和类冰酒的(残)糖达不到冰酒的VQA标准,酚类物质含量显著高于连体冷冻,冰酒感官上表现为颜色发褐,香气淡,口味欠协调,典型性不强。人工冷冻冰葡萄只能酿造普通型甜酒,而不能酿造高质量的冰酒。通过对不同来源的9种葡萄酒酵母的发酵性能及所酿冰酒的品质进行比较,选择出最适于酿造冰酒的酵母WY3,其次是WY4,WY1。WY1,WY3,WY4等酵母发酵性能可以满足冰酒生产的需要,且发酵的冰酒的理化指标均达到或高于国际标准。3种酵母发酵的冰酒各具特色:WY1发酵的冰酒总酯含量最高,酯香浓郁持久,是该冰酒的特色;WY3发酵的冰酒乙酸苯乙酯含量最高,具冰酒的典型风格;WY4发酵的冰酒高级醇的含量高,醇香较浓。采用正交试验以研究发酵温度、原料糖度、酵母种类和酵母加量等4个因素对冰酒挥发酸含量的影响,优化冰酒生产工艺。结果显示影响冰酒挥发酸含量的最主要因素是酵母菌种,其次是原料糖度。结合冰酒的感官质量和相关质量指标,提出桓仁产区优化的冰酒酿造关键工艺:采用挂枝离体冷冻方式,11月上旬、气温介于0℃~ 10℃之间进行葡萄带枝修剪,平均气温达到-18℃~-6℃进行采收,冰酒原料糖度分布在32 oBrix~50 oBrix之间,发酵时采用WY3酵母和WY4酵母进行发酵,酵母用量为0.3g/L,发酵温度为15℃~20℃。更多还原

【Abstract】 Vidal is the primary one of grape varieties to produce icewine in China at present, and it was used as experimental material in this study. The effects of key process such as compounds change in Vidal grape at stages of ripping and freezing, icewine material freezing ways and yeasts were studied during the year of 2008~2009 in Huanren, Liaoning province.The results were helpful to determine grape vine bury time and harvesting time, to find out reasonable freezing ways in Northeastern China and to screen regional and variety characteristic yeasts for icewine making. The paper also investigated the technical cause of high volatile acid level from icewine fermentation to find out technical conditions to reduce volatile acid level.Tracing weight, sugar and acid content during ripening of Vidal grape, it showed that Vidal grape didn’t grow any more since November 9th, 2009. Then grape clusters can be pruned and grape vine can be buried. Based on experimental research and the climate data (2007-2009), time and temperature were proposed as indicator to determine when vidal vine can be buried. First ten days of November and 0℃~10℃can be used to determined when vidal vine can be buried.By systematical analyzing the quality of raw material and icewine produced from different harvest time (temperature), the data showed that the quality of raw material and icewine produced from December 26th to January 10th both met Vintners Quality Alliance(VQA)standard. Based on experimental research and the climate data (2007-2009), time and temperature were proposed as indicator to determine the harvest time of vidal grape. The change of temperatures should be concerned since the first ten days of December. Grape harvest time can be determined based on the change of temperature The quality of icewine grape harvested during -18℃~-6℃met VQA standard, and these grapes could be fermented to produce high quality icewine.Physicochemical index and sensory quality of icewine raw material, icewine and fake icewine, treated by three kinds of freezing ways, were compared. It showed that there was no difference in physicochemical index of juices, compressed from the grape freezing on the vine or on the wire in natural environment, and there was no difference in physicochemical index and sensory quality of icewines fermented from these two grape juices, too. Physicochemical indexes of these two raw materials and icewines both reached VQA standard. The way grape freezing on the wire in natural environment could be used to acquire icewine raw materials. And it could enlarge icewine production areas. The sugar contents of artificially-frozen-juice and fake icewine both couldn’t met VQA standard. Tannins, total phenols contents of artificially-frozen-juice and fake icewine, were clearly higher than the former two treatments.“Fake icewine”was brown, less odorous, and imbalance. And this wine lacked the typicality of icewine.Nine commercially available wine yeast strains during icewine-making were compared.The performances of yeasts during icewine-making,physicochemical index,flavor compounds and sensory quality of 9 icewines were evaluated by means of meta-analysis. At last, WY1, WY3, WY4 were selected as candidates for icewine-making . And WY3 was the best for icewine-making . The fermentation performances of WY1, WY3 and WY4 met requirement of icewine making. And physicochemical indexes of three icewines fermented from WY1, WY3 and WY4 reached international standard. Each icewines had respective characteristic. Ice wine fermented from WY1 had strong but persisting ester odor character for its highest eater content. Icewine fermented from WY3 contained highest Phenylethyl acetate content, and showed typical icewine style. Icewine fermented from WY4 had high ethanol content, and emit dense ethanol aroma.Using the orthogonal design to study fermentation temperature, the sugar content, yeast and the dosage of yeast on influence of volatile acid level, it showed that the most influential factors on volatile acid level was yeast, the sugar content in the second place. In Huanren icewine region, the optimized major wine-making technology of icewine were as follows:grape freezing on the wire in natural environment; time and temperature of pruning of grape clusters (first ten days of November and 0℃~10℃); grape harvested time( -18℃~ -6℃); the sugar content was 32 oBrix ~50 oBrix; The yeast strains was WY3 and WY4; dosage of yeast was 0.3g/L; fermentation temperature was 15℃~20℃; according to sensory quality and related indexes of icewines.更多还原