人工贵腐葡萄酒香气的仪器分析与感官评价

Instrumental and Sensory Aroma Analysis of Noble-rot Wine from Artificial Botrytized Grapes

研究酿酒葡萄经人工侵染灰葡萄孢(Botrytis spp.)后所酿贵腐酒的香气特征,旨在正确评价该技术酿造贵腐葡萄酒工艺的可行性。酿酒原料采用陕西杨凌地区正常采摘的爱格丽葡萄,采用β-葡萄糖苷酶活性较高的优选灰葡萄孢菌株人工侵染葡萄和葡萄汁,以甜白葡萄酒工艺酿造葡萄酒,以传统甜白葡萄酒和风干原料甜白葡萄酒为对照。酿造次年对酒样进行GC-MS分析,同时培训品尝员进行香气特征的感官量化分析。人工贵腐葡萄酒中高级醇含量较低,而酯类和脂肪酸含量较高,乙酸酯类最为突出。人工贵腐葡萄所酿酒和风干原料葡萄酒中含有更多的品种香气成分,尤其是萜烯醇类和去甲类异戊二烯类化合物,因此对葡萄进行灰霉菌侵染和风干过熟处理均能促进香气前体物质的水解。本试验中,羟苯甲酯仅在人工贵腐葡萄酒中存在,是其典型成分,而人工贵腐葡萄所酿酒中特有的香气成分还有γ-癸内酯、苯乙酸和2-壬酮。感官分析结果表明,人工贵腐葡萄所酿酒具有明显的焦糖、甜杏、芒果、烘烤的香气特征,风味特征最为复杂,而人工贵腐葡萄汁所酿酒香气特征及其强度相对较弱。所以,经灰葡萄孢侵染葡萄所酿贵腐葡萄酒具有典型香气成分,风味复杂纯正,该技术具有应用的可行性。

It is known to all that noble-rot wine,a sweet wine made from botrytized grapes,has high cost for its special flavor. Aromas of sweet wines made from artificially botrytized grapes and botrytized juice were studied to evaluate the winemaking process of botrytized wines. Normally harvested Vitis vinifera Var. Ecolly grape was obtained in Yangling,Shaanxi Province,China. The grapes and juice were botrytized artificially by Botrytis spp. with high level of glycosidase activity. The winemaking process normally used for making sweet wine was used to make the artificial noble-rot wines. Normal sweet white wine and wine made from air-dried grapes were used as controls. The aromas of wine samples taken in April of the following year were subjected to chemical and sensory analyses. Botrytis-infected wines contained few higher alcohols but contained high esters and fatty acids,especially acetate esters,which were more likely due to high volatile acids induced by fungal infection. More varietal aroma-active compounds,especially terpenols and norisoprenoids,were detected in wines made from botrytized grapes and air-dried grapes than those in normal sweet white wine and botrytized juice made wine. The treatmentof over-ripe grapes promoted hydrolysis of aroma precursors, meanwhile, the metabolic activity of B. cinerea also promoted the hydrolysis. Moreover,hydroxy benzoate esters were typical compounds in botrytis-infected wines and γ-decalactone,phenyl acetic acid and 2-nonanone were unique in wine made from botrytized grapes. The wine made from botrytized grapes had the most complex aroma profile,with sweet fruity,caramel,mango and toast flavors; wine made from botrytized juice had fewer aromas.Therefore,grapes botrytized artificially with B. cinerea could be used to make noble-rot wines with high aroma quality.