【作者】 王艳辉；

【导师】 张玉星； 王颉；

【作者基本信息】 河北农业大学 ， 果树学， 2011， 博士

【摘要】 鸭梨（Pyrus bretschneideri Rehd cv. Yali）是中国传统医食同源植物。河北省是鸭梨生产大省,随着产量增加,鸭梨价格下降,果农增产不增收。梨酒营养丰富,香气馥郁,是世界各地常见果酒之一,酿造高品质鸭梨果酒,对增加鸭梨加工途径、提高鸭梨价值,以及促进果贱伤农问题的解决,具有积极意义。但是单纯用鸭梨发酵,梨酒口感薄淡。将不同水果混合酿酒,是改善果酒品质的常用方法,为提高鸭梨果酒感官品质,研究水果配料、酵母、工艺对鸭梨混合果酒品质的影响,本论文以鸭梨及山楂等11种果实分别混合作为发酵原料,采用主成分分析法比较了64种鸭梨混合酒的品质,利用GC-MS技术研究了混合梨酒的香气成分,检测了混合梨酒的抗氧化性能,继而比较了3种商品酵母对山楂-鸭梨混合酒的发酵适合性,利用均匀试验、响应面设计试验确定了山楂-鸭梨混合酒酿酒工艺,同时筛选到1株适于山楂-鸭梨混合酒专用的野生酵母菌株,并研究了此菌株的活性干酵母加工工艺。本论文对鸭梨混合酒感官品质和工艺进行了较系统的研究,试验结果如下:1.根据感官评定及主成分分析法构建了鸭梨混合酒品质的比较模型,11种水果中,山楂、葡萄、李子、苹果4种水果适于与鸭梨进行混合酿酒,所得果酒品质高于纯鸭梨酒,其中混合比为25:100的山楂-鸭梨酒品质最佳;雪花梨、南果梨、弥猴桃、柿子、枣5种水果不适于与鸭梨共同酿酒,所得混合梨酒品质低于纯鸭梨酒;茌梨、库尔勒香梨对梨酒品质无明显影响。2.山楂果浆与梨汁的混合比,对混合果酒的有机酸、多酚含量影响较大,混合比等于或低于25∶100时,果酒中有机酸为4.16-7.94g·L^-1,多酚为0.18-1.35g·L^-1,混合梨酒品质随混合比的加大而提高。3. 64种原料果汁中多酚、黄酮、低聚原花青素含量,与果酒中相应物质含量密切相关,以x₁、y₁分别代表果汁、果酒中黄酮浓度,则有y₁ = 0.6337 x₁- 0.0768,R² = 0.9737;64个原料果汁中的VC含量与果酒中的VC含量相关性较低,以x₂、y₂分别代表果汁、果酒中VC含量,则有y₂ =0.1578x₂ - 11.832,R² = 0.6857。4. 64种原料果汁中的抗氧化能力,与果酒的抗氧化能力密切相关。以FRAP法测定抗氧化能力,x、y分别代表果汁、果酒中FRAP值,则有y = 1.4666x - 0.307,R² = 0.9368。利用KFe[Fe（CN）₆]法、DPPH法测定抗氧化能力,可得相近结果。5.辛酸乙酯在鸭梨酒、山楂-鸭梨酒、葡萄-鸭梨酒、李子-鸭梨酒及苹果-鸭梨酒5种果酒中,均为主要香气成分,推测辛酸乙酯是鸭梨果汁发酵产生的特征性香气成分。6.在Oenoferm color活性干酵母、安琪葡萄酒用高活性干酵母、丹宝利酿酒高活性干酵母3种酿母中,丹宝利酿酒高活性干酵母在山楂-梨酒果汁中生长良好,所得山楂-梨酒香气浓郁,口感醇厚,最适于进行山楂-鸭梨酒的发酵。7.通过均匀设计试验及响应面设计试验,建立了温度（A ）、含糖量（B）、山楂梨汁混合比（C）对酒精度（Y）的二次多项回归模型: Y = 9.16-0.19A+0.88B-0.22C+0.042AB+0.015AC-0.028BC-0.51A²+0.048 B²-0.3C²。最佳发酵条件为:温度为25.18℃,含糖量22.00%,山楂梨汁混合比21.19:100,酒精度为10.05（V/V %）。8.通过富集培养、分离得到172株野生酵母菌株,经过生长性能、产酒精能力、感官评定、GC-MS香气分析四级筛选,得到1株较适于进行山楂-梨酒发酵的酵母菌株3#。9.通过单因素及正交试验,确定了3#菌株冷冻干燥最佳工艺: 36℃、PD培养基中摇瓶培养48小时,以4500R/m的转速离心20min收集酵母菌体,菌泥中加入4%甘油、10%麦芽糊精、7%蔗糖、2%脱脂牛奶作为复合保护剂,进行低温真空升华干燥,在此条件下酵母菌的存活率可达79.2%。更多还原

【Abstract】 Yali pear (Pyrus bretschneideri Rehd cv. Yali) is one of the traditional Herb-Food-Homologous plans in China. In Hebei province, the output of Yali pear is immense, but the income of pear planters is relatively small. Perries are rich in nutrition, strong in aroma, and popular in each corner around the globe. In order to multiply processing approaches, add extra values, and thus get rid of the dilemma of Yali pear production, it is advisable that high quality perry be produced. But Yali pear alone can merely produce light-flavored perry, poor in quality.Mixed brewing is always considered as an important way to improve the quality of fruit wines. On the purpose of improving the sensory quality of Yali wine, understanding the fruit, yeast and fermentation technology effect on Yali wine, in this study,11 kinds of fruit were used as raw material, mixed respectively with Yali pear and fermented. The mixed parrie qualities were compared via sensory evaluation and principal component analysis (PCA), the aroma components wres analyzed via GC-MS and the anti oxidant activity were tested. Then the optimal yeast for hawthorn– Yali wine was selected from 3 industrial yeast, the optimal fermentation conditions of making hawthorn- Yali wine was explored by uniform design and response surface design methods. At last, one wild yeast strains, 3#, was screened out as hawthorn- Yali wine specific yeast, and dry yeast process of 3 # was studied. Test results are as follows:1. According to sensory evaluation and principal component analysis results, hawthorn- Yali wine with mixing ratio of 25:100 has the best sensory quality. The quality of grapes- Yali wine, plums- Yali wine, apples- Yali wine also has been improved, that means these 4 kinds of fruit are suitable to ferment with pear. The quality of Xuehua pear–Yali wine, Kiwi- Yali wine, Nanguo pear- Yali wine, jujube Yali wine, persimmon- Yali wine is degraded, which mesns these 5 kinds of fruit are not suitable to ferment with pear. Chi pear and Korla pear have No significant effects on Yali wine quality.2. When the mixing ratio of hawthorn toYali pear is equal to or lower than 25∶100,.the organic acids in the mixed wine is 4.16-7.94 g ? L-1, polyphenols is 0.18-1.35 g ? L-1, and perry quality will improve with the mixing ratio increasing. 3. The concentrations of polyphenols, flavonoids and oligomeric proanthocyanidins of juice are correlated with those of mixed perries. x1, y1 stand for the flavonoids concentration of juice and mixed perry, the regression equation is: y1 = 0.6337x1-0.0768, R2 = 0.9737. VC concentration of juice do not show significant influence on the one of mixed parries, x2, y2 stand for the VC concentration of juice and mixed perry, the regression equation is: y2 = 0.1578x2 - 11.832, R2 = 0.6857.4. The antioxidant capacities of 64 kinds of juice are significantly correlated to the ones of mixed parries.Testing the antioxidant capacities by FRAP method, x, y stand for the FRAP value, the regression equation is: y = 1.4666x - 0.307, R2 = 0.9368. Using KFe [Fe (CN) 6] method and DPPH method can get similar results.5. In Yali wine, hawthorn- Yali wine, grapes- Yali wine, plums- Yali wine and apple- Yali wine, ethylcaprylate is main aroma component, which means ethylcaprylate is characteristic aroma components of Yali wine.6. Danbaoli high active dry yeast can grow well in hawthorn- Yali juice, and the perry fermented by Danbaoli yeast has more aroma components and better taste, which mean Danbaoli is more suitable for Hawthorn- Yali wine fermentation than Oenoferm color active dry yeast and Angel high active dry yeast.7. The model between temperature (A), sugar content (B), hawthorn, pear juice, mixing ratio (C) to alcohol degree (Y) was established: Y = 9.16-0.19A+0.88B-0.22C+0.042AB+0.015AC-0.028BC-0.51A2+0.048B2-0.3C2. The optimum fermentation conditions is: temperature 25.18℃, 22.00% sugar, hawthorn pear mixture ratio is 21.19:100. In this condition alcohol is 10.05 (V / V%).8. To get more suitable yeast for Hawthorn-pear wine, 172 strains of wild yeast were isolated, after comparing of growth performance, ethanol production capacity, sensory evaluation, GC-MS analysis ,3 # strain were selected.9. By a single factor and orthogonal experiment, the optimum produce conditions of Alcohol-fermentation Active DryYeast of 3 # strain is determined: culturing in PD medium under 36℃, shaking for 48 hours, then centrifugation 20min with 4500R / m speed, collecting the yeast. 4% glycerol, 10% maltodextrin, 7% sucrose, 2% skim milk are mixed as a composite protective agent to blend with yeast, and then processed with low-temperature vacuum distillation .In this condition, the survival rate of yeast is up to 79.2%.更多还原