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【目的】绿叶挥发物组分(Green Leaf Volatiles,GLVs)指植物中的不饱和脂肪酸通过酶代谢产生的短链脂肪族醛、醇和它们的酯类化合物,主要包括C6/9脂肪醛、醇和相应的酯。这些化合物不仅可以为葡萄果实和葡萄酒提供‘绿叶’、‘青草’或‘新鲜植物’味,而且是葡萄酒中果香成分之一乙酸己酯的直接前体物,对于酿酒葡萄和葡萄酒的香气品质具有重要贡献。本研究针对我国东部葡萄酒产区在酿酒葡萄成熟期降雨过多导致香气品质下降的问题,探究避雨栽培对‘赤霞珠’葡萄果实绿叶挥发物组分及其衍生酯类积累的影响,以期为该项措施的应用提供依据。【方法】本研究以2012和2013年采自北京密云地区张裕爱斐堡酒庄葡萄园(44°30?N,116°80?E)的赤霞珠(Vitis vinifera L.cv.Cabernet Sauvignon)果实为试材。采用固相微萃取-气相色谱与质谱联用技术,分析游离态和糖苷结合态香气物质的种类和含量,比较避雨栽培和露地模式下果实成熟过程中绿叶挥发物组分积累规律的异同。【结果】避雨栽培下葡萄果实周围的太阳总辐射和光合有效辐射下降约20%,紫外辐射下降约40%。在2012年避雨栽培的成熟果实可溶性固形物含量明显升高,而在2013年两种栽培模式生产的果实可溶性固形物和可滴定酸无显著差异。综合两年数据,避雨栽培降低了成熟果实有‘青草’气味的游离态脂肪醇、反式-2-己烯醛和反式-2-己烯酸的含量,而提高了结合态反式-2-己烯醇、己醇和反式-3-己烯醇等的含量、以及游离态和结合态己醛和己酸的含量。此外,避雨栽培也显著增加果实中有‘果香’气味的游离态和结合态酯类化合物含量,如乙酸己酯、辛酸乙酯和顺式-乙酸-3-己烯酯等。相对于2013年,避雨栽培的这些影响在降雨量相对较多的2012年更为显著。【结论】避雨栽培可以减弱葡萄的绿叶气味,提升果实和葡萄酒潜在果香品质,尤其在降雨相对较多的年份,可有效地缓解果实品质的下降。
【Objective】 Green Leaf Volatiles (GLVs) refer to short chain aliphatic aldehydes, alcohols and their esters produced by enzymatic metabolism of unsaturated fatty acids in plants, including C6 / 9 fatty aldehydes, alcohols and corresponding Of the ester. These compounds not only provide ’green leaf’, ’grass’ or ’fresh plant’ notes to grape fruit and wine, but also direct precursors of hexyl acetate, a fruit-flavoring ingredient in wine, to the aroma quality of wine grapes and wines Has an important contribution. In this study, aiming at the problem of the decrease of aroma quality in the wine region of eastern China caused by excessive rainfall during the ripening stage of wine grape, the effects of shelter-rain cultivation on the components of green leaf volatiles and the derivatization of ester species in ’Cabernet Sauvignon’ Provide the basis for the application of this measure. 【Method】 The study was conducted in 2012 and 2013 with samples collected from Vitis vinifera L.cv. Cabernet Sauvignon (44 ° 30? N, 116 ° 80? E) in the vineyard of Changyu Aiba Fort in Miyun, Fruit for the test material. Solid-phase microextraction-gas chromatography-mass spectrometry (GC-MS / MS) was used to analyze the types and contents of free-form and glycoside-bound aroma compounds. The similarities and differences of the components of green leaf volatile matter accumulation during rain-ripening and field- 【Result】 The results showed that the total solar radiation and photosynthetically active radiation around grape fruits decreased by about 20% and the UV radiation decreased by about 40% under rain-sheltered cultivation. In 2012, the content of soluble solids in shelled fruits increased significantly, while no significant differences were found between soluble solids and titratable acids in the two cultivation modes in 2013. Based on the data from two years, rain shelter reduces the contents of free fatty alcohols, trans-2-hexenal and trans-2-hexenoic acid in ripe fruit with “grassy” odor, and increases the content of bound trans- 2-hexenol, hexanol, trans-3-hexenol and the like, as well as the contents of free and bound hexanal and caproic acid. In addition, rain shelter cultivation also significantly increases the content of free and bound ester-like compounds with ’fruity’ odor in fruits such as hexyl acetate, ethyl octanoate and 3-hexenyl cis-acetate. Compared with 2013, these effects of rain sheltering were more pronounced in 2012 when rainfall was relatively higher. 【Conclusion】 Rain-shelter cultivation can reduce the green leaf odor of grapes and enhance the potential fruit-wine quality of fruits and wines, especially in relatively high rainfall years, which can effectively reduce the decline of fruit quality.