一年两收栽培夏黑葡萄香气成分分析

【目的】分析一年两收栽培夏黑葡萄夏果和冬果的香气成分，为提高该品种的芳香品质及促进其一年两收栽培技术的发展提供理论依据。【方法】以8年生一年两收栽培的夏黑葡萄为试验材料，于始转色期、成熟期和成熟后期采集夏果和冬果。采用HS-SPME-GC-MS方法，分别对夏果和冬果3个时期的香气成分进行定性定量分析，并监控不同发育期持续天数、气象指标和浆果理化指标的变化。【结果】一年两收栽培夏黑葡萄从萌芽到成熟过程中，夏果的每日气温逐渐上升，而冬果的每日气温逐渐降低，冬果较夏果转色期更早，成熟期持续的时间更长。成熟期冬果可溶性固形物和可滴定酸含量均高于夏果；夏果和冬果于始转色期、成熟期和成熟后期分别检测到48、51、47种和52、56、56种香气成分，包括醛类、醇类、酯类、酮类、萜烯类和酸类。冬果3个时期的香气成分总含量分别为472.83、1020.27和836.43 μg/L，均显著高于夏果的459.39、638.57和659.20 μg/L（P<0.05，下同）。成熟期夏黑葡萄中香气成分含量最高的是醛类化合物，其次是醇类化合物，夏果和冬果中醛类化合物含量分别为446.34和600.18 μg/L，醇类化合物含量分别为120.21和163.44 μg/L。成熟期夏黑葡萄中单体类香气成分以C₆化合物为主，其中含量最高的是青草及苹果香味的己醛，其后依次是草本香和果香型的2-己烯醛、（Z）-3-己烯醛和己醇，冬果中上述单体类化合物的含量均显著高于夏果。成熟期夏果和冬果中最具代表性的8个差异香气化合物为2-己烯醛、乙酸乙酯、香茅醇、苯乙醇、橙花醇、（Z）-3-己烯醛、香叶醇和辛酸乙酯，冬果中上述差异化合物的含量均显著高于夏果。通过对气候条件的分析，与夏果相比，夏黑葡萄冬果生长季后期冷凉的环境和更为干燥的气候是其香气成分含量显著高于夏果的主要原因。【结论】一年两收栽培模式下两季葡萄果实香气成分组成和含量的差异是气象因子综合作用的结果，冬果生长季的气候条件更有利于葡萄芳香品质的提高。

Aroma components analysis of Summer Black grape under two-crops-a-year cultivation

【Objective】The aroma components in summer and winter grapes of Summer Black grape cultivated in twocrops-a-year system were analyzed, in order to provide theoretical basis for improving its aroma quality and promotion of two-crops-a-year cultivation.【Method】Eight-year-old Summer Black grape vines which cultivated under a two-crops-ayear cultivation were used as the material, the summer and winter grapes were collected at veraison, ripening and late ripening stages. Headspace-solid phase microextraction(HS-SPME) and gas chromatography-mass spectrometry(GC-MS) were used to qualitatively and quantitatively analyze the aroma components of these three stages of summer and winter grapes, and the changes of duration days, meteorological indexes and berry physicochemical indexes in different developmental stages between summer and winter grapes were monitored.【Result】From budding to ripening, the daily temperature increased gradually in summer grapes, while decreased gradually in winter grapes. In winter grapes, the veraison was earlier and the duration of ripening process was longer than summer grapes. The soluble solids content and titratable acids content in ripen winter grapes were higher than that in summer grapes. A total of 48, 51, 47 and 52, 56, 56 aroma components were identified in summer and winter grapes at veraison, ripening and late ripening stages, respectively, including aldehydes, alcohols, esters, ketones, terpenes and acids. The total content of aroma components in the three stages of winter grapes were 472.83, 1020.27 and 836.43 μg/L, respectively, which were all significantly higher than that in summer grapes(459.39, 638.57 and 659.20 μg/L, respectively) (P<0.05, the same below). The content of aldehydes was the highest in ripen Summer Black grape, followed by alcohols. In ripen summer and winter grapes, the contents of aldehydes were 446.34 and 600.18 μg/L respectively, and the contents of alcohols were 120.21 and 163.44 μg/L respectively. The monomer aroma components were mainly C₆ compounds, among which the compound with the highest content was hexanal with grass and apple fragrance, followed by 2-hexanal, (Z) -3-hexanal and hexanol, showed herbaceous and fruity flavors. The content of the above monomer aroma compounds in winter grapes of Summer Black grape was all significantly higher than that in summer grapes.The most representative eight differential aroma compounds in ripen summer and winter grapes were 2-hexanal, ethyl acetate, citronellol, phenethyl alcohol, nerol, (Z) -3-hexanal, geraniol and ethyl caprylate, and the contents of these differential compounds in winter grapes were significantly higher than that in summer grapes.Through the analysis of climate conditions, compared with the summer grapes, the cold environment and drier climate in the late growing season of winter grapes were the main reasons for the significantly higher aroma content in winter grapes of Summer Black grape than that in summer grapes.【Conclusion】The difference of aroma compounds composition and contents between summer and winter grapes under two-crops-a-year cultivation is the result of the comprehensive effect of meteorological factors, the climate conditions in winter grapes growing seasonis more favorable for grape aroma quality improvement.