酿酒葡萄果-蒂振动分离试验

为深入研究酿酒葡萄果-蒂振动分离特性,寻求影响分离效果因素的最优组合,该文基于酿酒葡萄做变速运动产生惯性力克服葡萄果-蒂连接力实现分离的原理,搭建了曲柄摇杆机构分离率测定装置。通过对曲柄摇杆机构运动及果-蒂分离临界条件的分析,构建了果-蒂振动分离模型,确定电机转速、偏心距离及摇杆长度为主要影响因素,并针对霞多丽和赤霞珠品种开展试验研究。结果表明:影响酿酒葡萄分离率显著因子的主次顺序为偏心距离、摇杆长度和电机转速;赤霞珠品种较霞多丽品种更适合机械采收;当转速为245 r/min,偏心距离为75 mm,摇杆长度为200 mm时,赤霞珠分离率为95.2%,葡萄果-蒂分离的频率范围为2.11~3.69 Hz,葡萄穗梗处的振幅为169.8 mm。该文研究结果可为酿酒葡萄收获装置的设计提供理论依据。     

摘叶对赤霞珠葡萄及所酿葡萄酒品质的影响

为探讨摘叶对烟台产区赤霞珠葡萄及所酿葡萄酒主要品质的影响,本试验以山东蓬莱的6年生赤霞珠葡萄为试验材料,在转色期(花后70 d)及采收期前10 d(花后143 d)进行半摘叶和全摘叶处理,研究不同时期和摘叶方式对赤霞珠葡萄的理化指标、品质指标的影响。结果表明,在不同发育时期摘叶处理都能够有效地提高葡萄果实的成熟度及其葡萄酒的综合品质。其中,花后70 d全部摘叶处理对糖、滴定酸以及p H值的提高效果明显;转色期半摘叶和全摘叶处理后葡萄果实中总酚和单宁含量分别提高了17.96%和50.25%,所对应的葡萄酒中总酚和单宁含量也分别提高了40.18%和54.13%;此外,摘叶处理对赤霞珠葡萄及所酿葡萄酒中香气物质的骨架影响不大,但对香气成分的含量影响较大,转色期半摘叶处理使呈现果香的香气物质含量提高明显;转色期全摘叶处理使葡萄酒中色度提高效果最明显,达到了16.48%;4种摘叶处理均使葡萄酒色调降低,使得葡萄酒颜色呈现淡紫色。本研究对酿酒葡萄赤霞珠在田间管理和提高葡萄酒质量方面提供了理论依据及技术支持。     

美乐葡萄在乳山和德州地区品质特征比较分析

美乐葡萄是山东省酿酒葡萄主要栽培品种之一,主要分布在胶东半岛。为了了解美乐葡萄在山东省的栽培表现,对位于胶东半岛的乳山台依湖酒庄与德州奥德曼酒庄种植的美乐葡萄的品质性状及其在转色期到成熟期的变化情况进行了分析。结果表明,在成熟期,德州地区葡萄果实中花色苷、酚类含量较高,乳山地区的可溶性糖和总有机酸含量较高。从转色期到成熟期,乳山葡萄果实中可溶性糖含量变化较快,德州总花色苷含量变化较快,其他性状变化程度相近。进一步对差异表达基因（DEGs）分析发现,乳山的DEGs数量高于德州。此外,这些DEGs共富集到824组GO功能组和114条KEGG生物学途径。对一些与品质相关的KEGG通路与GO条目进行分析发现,上调或下调基因的数量可能与果实表现出的农艺性状有关。本研究结果为胶东半岛以及黄河流域进一步引种推广美乐葡萄以及发展具有区域特色的美乐葡萄酒提供了理论依据。     

转色期叶面氮素调控对酿酒葡萄'赤霞珠'品质的影响

宁夏贺兰山东麓现阶段水肥一体轻简化栽培模式下酿酒葡萄对氮素营养需求发生了巨大变化,如果继续沿用传统氮肥施用方式可能会引发酿酒葡萄成熟过快、浆果内含物累计不足、果皮中酵母可同化氮偏低等问题。以喷清水为对照,在酿酒葡萄转色期内叶面喷施硫酸铵、硝酸铵钙、尿素、苯丙氨酸及谷氨酸5种水溶性氮源,研究不同氮源对酿酒葡萄''赤霞珠''品质的影响。结果表明：转色期叶面氮素调控的葡萄浆果可溶性固形物以硫酸铵处理最佳,高达29.21%;花色苷在尿素处理下含量高达2.28 mg/g,较其余氮素处理提高16.33%～55.10%;单宁含量以苯丙氨酸处理最佳,高达19.88 mg/g;总酚含量在苯丙氨酸处理下高达19.56 mg/g,较其余氮素处理提高8.91%～27.34%。综合分析得出,转色期叶面喷施苯丙氨酸和尿素两种氮源均可改善酿酒葡萄生长发育,提升浆果品质。     

克里雅河流域植被物候时空变化及影响因素

[目的] 探究克里雅河流域2000—2015年植被物候期时空变化规律,在气候变化背景下为该流域植被演变过程研究提供参考。[方法] 以MODIS MOD₀₉Q₁产品和当地气象站点数据为数据源,利用植被指数动态阈值法提取流域植被物候信息并进行空间趋势分析,以偏最小二乘回归方法分析克里雅河流域植被物候期与不同月份气象因子的相关性。[结果] ①研究期内植被生长期开始时间主要在第60—180 d之间,结束时间在第180—322 d之间,植被生长期长度在70~250 d之间。中游的人工绿洲植被生长期开始时间最早,结束时间最晚,植被生长时间最长。②2000—2015年克里雅河流域植被返青期整体呈提前趋势,变化速率均值为-1.3 d/10 a,植被枯黄期呈推迟趋势,生长期延长,其中以中游的变化趋势最为明显。③春季气温和降水量的升高促进植被返青期提前,秋季气温和降水量的升高会对植被枯黄期起到推迟作用。[结论] 克里雅河流域植被物候期在不同的海拔梯度上有明显的分布变化规律,中游人工绿洲植被的物候变化规律远异于自然植被物候变化规律,并且可能影响到了下游。     

转色期BTH诱抗改变霞多丽葡萄果实理化品质和香气构成

为探讨苯并噻二唑(benzothiazole,BTH)转色期诱抗处理对葡萄果实理化和香气品质的影响,该研究以酿酒葡萄‘霞多丽’为试材,果实转色50%时对植株喷施50 mg/L的诱抗剂BTH,分析比较成熟葡萄果实的理化和香气品质指标。结果表明：与对照相比,转色期BTH诱抗处理可显著增加8.31%的葡萄果皮/浆果比例(P<0.05);极显著增加果实百粒质量、可溶性固形物和还原糖,分别较对照吐温80水溶液处理增加了4.64%、6.67%和8.63%(P<0.01)。但BTH处理会降低总类胡萝卜素、叶绿素和可滴定酸的含量。同时,BTH诱抗减少了果实中游离态C₆/C₉、芳香族、支链脂肪族和降异戊二烯香气组分的积累,降低比例在16.65%～31.77%之间;BTH促进了游离态直链脂肪族和萜烯类以及结合态C₆/C₉、直链脂肪族、芳香族、萜烯类和降异戊二烯香气组分在果实中的积累,增加比例在4.22%～60.12%之间。综上可见,转色期BTH诱抗处理可通过增加果皮/浆果比例、可溶性固形物和还原糖含量改善‘...     

基于多因素模型重构陕西苹果主要物候数据序列

苹果生长发育受气象因素影响较大,陕西高低温灾害发生频率的增加对苹果的产量和品质有很大影响。物候期的确定是指导果业生产、进行灾害风险管理的重要依据。目前,物候期观测数据十分匮乏,通过构建物候模型可对历史物候期进行重构。在陕西的四个果区,分别选取物候资料记录相对全面的两个代表站点,礼泉和凤翔（关中果区）、旬邑和长武（渭北西部果区）、铜川和白水（渭北东部果区）、延长和洛川（延安果区）。在各果区的两个代表站点中,选取历史物候期记录时间序列更长的站点,利用SPSS软件对该站点物候期日序与所选气象指标进行逐步回归分析,建立多个单项或多项物候期预测模型,再通过回代检验和预测检验两种方法选取最优模型。采用平均绝对误差（MAE）、物候期模拟值与实际值相差0～3d的相对准确率（RA）评估检验结果,并选择最优模型。结果表明：（1）萌芽期模型MAE为0.8～2.4d,RA为84.6%～100%;花期模型MAE为2.5～3.4d,RA为55.6%～75%;果实发育期模型MAE为0.9～2.8d,RA为63.2%～100%;成熟期模型MAE为2.2～3.2d,RA为69.2%～72.2%;模型模拟效果由好到差依次为萌芽期、果实发育期、成熟期和花期。（2）重构1981−2019年延安果区、渭北东部果区、渭北西部果区和关中果区苹果萌芽期年日序分别为72−98、70−88、73−98和71−85,花期年日序分别为102−116、86−107、100−125和84−115;1981−2019年延安果区、渭北东部果区和关中果区苹果果实发育期年日序分别为114−122、89−118和87−117,成熟期年日序为260−301、276−297和224−348。（3）重构物候期的空间分布,1981−2019年延安果区和渭北东部果区萌芽期由东南向西北逐渐推迟,关中果区和渭北西部果区自西向东推迟;花期整体自南向北越来越晚;果实发育期从南向北逐步推迟;延安果区和渭北东部果区成熟期从东向西逐步推迟,关中果区和渭北西部果区自西向东逐步推迟。本研究构建的物候模型的模拟效果总体较好,所重构的苹果物候期数据序列可为苹果生产管理和灾害风险防范提供基础性支撑,对果树物候期模型的研发具有借鉴意义。     

基于遥感的甘肃省庆阳市植被物候信息提取

以黄土高原退耕还林还草工程重点区域——甘肃省庆阳市为研究区域,利用1999—2012年的SPOT-VGT NDVI数据,采用Savitzky-Golay滤波和TIMESAT物候提取算法,得到了庆阳市近14 a返青期和枯黄期数据,详细描述了庆阳市物候期时空变化格局。结果表明:庆阳地区近14 a期间返青期日序位于90~188天,东南地区相对于西北地区返青期要早,表现出较强的空间差异性,枯黄期日序位于275~309天,南部地区相对北部地区枯黄期要晚;从时间上来讲,14 a间,庆阳市返青期日序呈降低趋势,在一定程度上呈现出返青期的提前和枯黄期的推迟;空间上来讲,55.46%的研究区返青期变化率基本不变（-1~1 d/a）,49.61%的区域出现了枯黄期的推迟（1~3 d/a）。研究结果与已有的研究较为一致,并详细描述了庆阳市物候期时空变化格局,可为中国北方农牧交错带生态环境评估和保护提供一定的参考。     

补氮方式对酿酒葡萄转色期生理调节及品质的影响

氮肥在促进酿酒葡萄营养生长的同时还能有效调节其生殖生长,补氮时期和补氮方式对于协调葡萄营养生理和品质构成的关系尤为重要,尤其在葡萄品质形成最为关键的转色期进行氮素调控对浆果品质组分的影响最为显著。以8年生酿酒葡萄品种“赤霞珠”为研究对象,在葡萄转色期内以清水为对照,设置叶面喷施、滴灌补氮、喷滴结合和减量补氮4种补氮方式,研究补氮方式对葡萄生理、品质和酵母可同化氮的影响。结果表明：与喷施清水相比,4种补氮方式均能提高葡萄果实的果形指数;滴灌补氮能有效增加叶片叶面积、水分利用率和叶绿素b含量,其中水分利用率显著提高81.53%;葡萄浆果的单宁、花色苷和总酚提升效果在叶面喷施氮素时分别显著提高11.69%、99.19%、21.60%;减量补氮可以显著促进叶绿素的合成与积累,同时可溶性固形物显著增加16.15%;喷滴结合提升叶片净光合速率、类胡萝卜素和酵母可同化氮含量的效果最佳,分别显著增加35.15%、38.46%和53.04%,同时百粒重显著提高44.88%。综合评价发现,在贺兰山东麓葡萄酒产区通过叶面喷施和滴灌追施的补氮方式是调节酿酒葡萄生理、改善葡萄浆果品质的有效途径。     

山东地区木本植物春季物候对气候变化的响应

利用山东省境内10个国家级农业气象观测站1981-2009年逐年春季物候序列和同期逐日气象资料,通过一元线性回归、相关分析和突变检验方法,分析了山东地区木本植物春季物候期的趋势变化特征及物候期对气候变化的响应关系。结果表明：（1）1980-2009年山东地区春季气温明显升高,春季水汽压呈增大趋势;（2）山东地区近29a的木本植物春季物候期普遍提前,提前的线性倾向率为0.13～1.11d.a-1;（3）山东地区木本植物春季物候期与其前期活动积温、春季气温和3月份水汽压呈负相关关系,物候前期的活动积温是诱发春季物候现象的重要因子,春季气温升高和3月份水汽压增大是近29a春季物候现象提前的可能原因。     

Antioxidant capacities and phenolics levels of French wines from different varieties and vintages.

Phenolics from grapes and wines can play a role against oxidation and development of atherosclerosis. Levels of phenolics, major catechins [(+)-catechin, (-)-epicatechin, procyanidin dimers B1, B2, B3, and B4], phenolic acids (gallic acid and caffeic acid), caftaric acid, malvidin-3-glucoside, peonidin-3-glucoside, and cyanidin-3-glucoside were quantified by HPLC with UV detection for 54 French varietal commercial wines taken from southern France to study the antioxidant capacity and the daily dietary intake of these compounds for the French population. The highest antioxidant capacity was obtained with red wines and ranged from 12.8 mmol/L (Grenache) to 25.2 mmol/L (Pinot Noir). For white wines, Chardonnay enriched in phenolics by special wine-making was found to have an antioxidant capacity of 13.8 mmol/L, comparable to red wine values. For red wines classified by vintages (1996-1999) antioxidant capacities were approximately 20 mmol/L and then decreased to 13.4 mmol/L for vintages 1995-1991. Sweet white wines have 1.7 times more antioxidant capacity (3.2 mmol/L) than dry white wines (1.91 mmol/L). On the basis of a still significant French wine consumption of 180 mL/day/person, the current daily intake of catechins (monomers and dimers B1, B2, B3, and B4) averaged 5 (dry white wine), 4.36 (sweet white wines), 7.70 (rosé wines), 31.98 (red wines), and 66.94 (dry white wine enriched in phenolic) mg/day/resident for the French population. Red wine, and particularly Pinot Noir, Egiodola, Syrah, Cabernet Sauvignon, and Merlot varieties, or Chardonnay enriched in phenolics during wine-making for white varieties contribute to a very significant catechin dietary intake.     

Rapid method for the discrimination of red wine cultivars based on mid-infrared spectroscopy of phenolic wine extracts

Mid-infrared spectroscopy and UV-vis spectroscopy combined with multivariate data analysis have been applied for the discrimination of Austrian red wines, including the cultivars Cabernet Sauvignon, Merlot, Pinot Noir, Blaufr?nkisch (Lemberger), St. Laurent, and Zweigelt. Both authentic wines and their phenolic extracts were investigated by attenuated total reflectance (ATR)-mid-infrared spectroscopy. Phenolic extracts were also investigated by UV-vis spectroscopy. The wine extracts were obtained by solid-phase extraction with C-18 columns and elution by methanol containing 0.01% hydrochloric acid. Hierarchical cluster analysis was performed with mid-infrared spectra of both wines and extracts, as well as with UV-vis spectra of the phenolic extracts. Data processing involved vector normalization and derivation of the spectra. Due to varying concentrations of main components including sugar and organic acids, satisfactory classification of untreated wines was not achieved. However, when using mid-infrared spectra of the phenolic extracts, almost complete discrimination of all cultivars investigated was achieved. The use of UV-vis spectroscopy for cultivar discrimination was found to be limited to the authentication of the Burgundy species Pinot Noir. In addition, soft independent modeling of class analogy was applied to the mid-infrared spectra of the extracts. It was possible to establish class models for five different wine cultivars and to classify test samples correctly.     

Sensory threshold of 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN) and concentrations in young Riesling and non-Riesling wines

1,1,6-Trimethyl-1,2-dihydronaphthalene (TDN) is well-known to contribute "petrol" aromas to aged Riesling wines, but its prevalence and contribution to young Riesling or non-Riesling wines is not well understood. TDN concentrations were measured in 1-3-year-old varietal wines produced from Cabernet franc (n = 14 wines), Chardonnay (17), Cabernet Sauvignon (4), Gewurztraminer (4), Merlot (9), Pinot gris (6), Pinot noir (9), Riesling (28), or Sauvignon blanc (6). TDN concentrations in the Riesling wines, 6.4 ± 3.8 μg/L, were significantly higher than in all other varietals, 1.3 ± 0.8 μg/L. The odor detection thresholds for TDN were then determined in both model wine and a neutral white wine. Group sensory thresholds were found to be the same in both matrices, 2 μg/L, indicating little masking of TDN due to the odorants in the neutral white. The TDN sensory threshold was a factor of 10 below the previously reported odor threshold. On the basis of this revised threshold, 27 of 28 Riesling wines had suprathreshold TDN, whereas only 7 of 69 non-Riesling wines had suprathreshold TDN. The monoterpenes linalool and geraniol were also measured in the Riesling wines, and odor activity values (OAVs) were calculated for the monoterpenes and TDN. The OAV for TDN was higher than for the monoterpenes in 25 of 28 Riesling wines.     

Effect of red grapes co-winemaking in polyphenols and color of wines

The red grapes co-winemaking effect on phenolic fraction and wine color has been studied for the first time, where Monastrell was comacerated and cofermentated with Cabernet Sauvignon and Merlot. Changes in the relative abundance of anthocyanins were observed as well as hyperchromic shifts at 530 and 620 nm; these effects remain constant after aging. Co-winemaking also favored copigmentation, giving way to more stable anthocyanins and facilitating their polymerization. With regard to color evolution, the mixture of Monastrell with Merlot grapes was more appropriate than with Cabernet Sauvignon for aging wines in oak barrels. The extent of copigmentation was more important in young wines than in aged wines. This is mainly due to the self-anthocyanin monomer reactions in the case of young wines, whereas in aged wines copigmentation is mainly due to the reaction between the anthocyanins and other polyphenolic cofactors. Discriminant analysis showed the possibility of differentiating wines according to the aging time and the type of wine, with color parameters (color intensity, OD 620 nm, and OD 520 nm) being the most important discrimination variables in the first case and petunidin-3-glucoside and peonidin-3-glucoside contents in the second case.     

Effect of vineyard-scale climate variability on Pinot noir phenolic composition

The sensitivity of agricultural crops to climate change is a major area for climate impact studies. The relationship between climate and three key phenolic compounds in grape skins important to premium wine quality (anthocyanins, tannins, and total phenolics) has not been well-studied. Here we conducted a three-year field study to collect and analyze berry samples from Pinot noir vineyards in the Carneros and Sonoma Valley American Viticultural Areas of California's North Coast wine country, and correlate phenolic measurements with climate statistics derived from hourly temperature measures at each vineyard site. We used several statistical approaches to identify key phenologically-based periods influencing phenolic concentration at maturity, including classification and regression trees, factor screening, principal component analysis, and pairwise correlations.The results from these statistical models showed that cool conditions following harvest the year before maturity, warm temperatures from budburst to bloom, and cool temperatures from bloom to veraison (the onset of ripening) were positively correlated with concentrations of all three classes of phenolics, although not all trends were statistically significant. Anthocyanins were positively and significantly correlated with temperatures between 16 and 22 °C from veraison to harvest. Tannins were significantly increased by warm nights preceding budburst and warm days from budburst to bloom. We measured relatively high levels of light interception (35% of incident photosynthetically active radiation), and we found that increased light interception was significantly correlated with lower levels of all three classes of phenolic compounds in this study.For the Pinot noir sites in this study, warm temperatures from budburst to bloom appear to increase phenolic concentrations, which is likely beneficial for wine quality. However, warmer periods during the preceding fall and summer during ripening appear to offset these effects. Given projections for greater summer warming in California with climate change, the overall impact of climate change on winegrowing is likely to be negative.     

Variations in the profile and content of anthocyanins in wines made from cabernet sauvignon and hybrid grapes

To detect adulteration of wine, it has been proposed that the ratio of acetylated to p-coumaroylated conjugates of nine characteristic anthocyanins can be used to determine whether a wine is derived from Cabernet Sauvignon or hybrid grapes. If the ratio is >3, then a wine is classified as being derived from Cabernet Sauvignon grapes. This test has significant commercial implications as it is being used to decide whether Cabernet Sauvignon-labeled wines are genuine and can be imported into Germany. To assess whether this is a valid approach, 24 wines were analyzed, 4 of which were made from hybrids and 20 from Cabernet Sauvignon, with vintages ranging from 1993 to 2000. Only 13 of the Cabernet Sauvignon wines contained all nine of the "characteristic" anthocyanins, and the ratio of acetylated to p-coumaroylated derivatives varied from 1.2 to 6.5. It is evident that the use of the anthocyanin ratio method is flawed and that examination of the whole anthocyanin profile and/or investigation of the proportion of monoglucoside and acetylated anthocyanins is a better approach to distinguish between hybrid and Cabernet Sauvignon wines.     

Ripening-induced changes in grape skin proanthocyanidins modify their interaction with cell walls

Proanthocyanidins were isolated from the skins of Cabernet Sauvignon grapes at different stages of grape development in order to study the effect of proanthocyanidin modification on the interaction with grape cell wall material. After veraison, the degree of proanthocyanidin polymerization increased, and thereafter was variable between 24 and 33 subunits as ripening progressed. Affinity of skin cell wall material for proanthocyanidin decreased with proanthocyanidin ripeness following veraison. A significant negative relationship (R2=0.93) was found for average proanthocyanidin molecular mass and the proportion of high molecular mass proanthocyanidin adsorbed by skin cell wall material. This indicated that as proanthocyanidin polymerization increased, the affinity of a component of high molecular mass proanthocyanidins for skin cell wall material declined. This phenomenon was only associated with skin proanthocyanidins from colored grapes, as high molecular mass proanthocyanidins of equivalent subunit composition from colorless mutant Cabernet Sauvignon grapes had a higher affinity for skin cell wall material.