紫外处理对酿酒葡萄果皮中白藜芦醇及其二聚体合成的影响

本文研究了紫外线辐射对酿酒葡萄品种蛇龙珠果皮中白藜芦醇及其二聚体合成的影响.研究结果表明,紫外线辐射300 s,在35℃下黑暗中贮存24 h后,可明显提高果皮中白藜芦醇及其二聚体含量.紫外线辐射对不同发育期果皮中白藜芦醇及其二聚体含量的影响并不相同,对白藜芦醇含量来说,果实转色期时紫外诱导效果最好;对白藜芦醇二聚体而言,不同时期的紫外诱导效果差异不显著.紫外线辐射均能提高苯丙氨酸裂解酶和过氧化物酶活性,且苯丙氨酸裂解酶活性与果皮中白藜芦醇的形成之间存在相关性,过氧化物酶活性与果皮中自藜芦醇二聚体的形成存在相关性.     

山葡萄果实发育过程中花色苷和非花色苷酚成分及其含量的变化

以‘双红’山葡萄果实为试材,采用HPLC—MS／MS技术,分析山葡萄果实发育过程中果皮中花色苷和非花色苷酚成分及其含量的变化。结果表明,转色期前果皮内没有花色苷积累,随着果实的成熟,花色苷含量逐渐增加,成熟期的含量最高;非花色苷酚自花后2周至成熟期间的含量变化呈下降趋势。在山葡萄果实发育过程中检测出花色苷10种,其中双糖苷5种、单糖苷5种;非花色苷酚类物质检测到14种,其中苯甲酸类2种、肉桂酸类3种、黄烷-3-醇类2种、黄酮醇类5种、白藜芦醇类2种。     

薄层层析-紫外分光光度法测定葡萄果皮中白藜芦醇及白藜芦醇苷

建立了葡萄果皮中反式白藜芦醇及反式白藜芦醇苷含量的薄层层析-紫外分光光度测定法.以甲醇提取目标组分,以高效硅胶GF254为固定相,甲苯:乙酸乙酯:甲酸(5:4:1)为展开剂,对反式白藜芦醇及反式白藜芦醇苷进行分离纯化.并用紫外分光光度法进行定量,波长为306 nm.结果表明,该方法测定反式白藜芦醇及反式白藜芦醇苷含量的线性关系良好,相关系数为0.9997;平均回收率为98.12%、97.23%;方法的精密度较高.并用该方法测定了酿酒红葡萄品种蛇龙珠不同生长时期的反式白藜芦醇和反式白藜芦醇苷含量.     

葡萄植株中白藜芦醇及葡萄素含量动态积累规律研究

对葡萄生长期间不同部位中主要活性成分白藜芦醇和葡萄素含量进行了分析,探索了活性成分代谢积累规律.以湖南省境内的主要葡萄品种红地球的主藤、侧藤、支藤、根、叶、叶柄为研究对象,从2010年4月到2011年1月考察了白藜芦醇与葡萄素含量的动态变化,采用超声波辅助甲醇提取法对实验材料进行白藜芦醇和葡萄素提取,以高效液相色谱法进行白藜芦醇和葡萄素含量测定来考察白藜芦醇和葡萄素在葡萄植株中动态变化的规律.结果表明:葡萄植株中不同部位白藜芦醇和葡萄素含量差异显著,主藤＞侧藤＞支藤＞根＞叶片≈叶柄;各部位白藜芦醇和葡萄素在生长期含量变化趋势是先升后降,尤其是葡萄素变化趋势很明显,白藜芦醇变化趋势较小,各部位芪化物含量在9～10月含量处于峰值.     

酿酒葡萄赤霞珠果实苹果酸生物合成关键基因的功能鉴定

针对近些年来葡萄果实有机酸含量受全球气候变暖影响而严重不足,酿造的葡萄酒风味和口感欠佳等问题,以宁夏地区栽培面积最多的赤霞珠(Cabernet Sauvignon)酿酒葡萄品种为材料,从果实形成至成熟4个生长时期(每个时期2次采样)的果实中提取RNA进行转录组测序,同时对同一时期的果实中与苹果酸生物合成关系密切的8种有机酸进行测定,通过基因表达量与有机酸含量的关联分析,筛选出影响赤霞珠果实中苹果酸生物合成途径的8种关键基因,并对其进行分离克隆、原核细胞表达和体外酶活性检测,从而确定各个关键基因及其同源基因的序列变化和功能差异,为今后酿酒葡萄有机酸含量的遗传调控、优质酿酒葡萄的培育提供帮助。     

葡萄酒中白藜芦醇的分析

采用HPLC测定了17种葡萄酒中白藜芦醇含量。干红葡萄酒中白藜芦醇的含量远高于干白葡萄酒。干红葡萄酒中白藜芦醇的含量与葡萄品种有关,同一葡萄品种的干红葡萄酒中白藜芦醇的含量与产地和工艺有关。     

超声辅助萃取葡萄分子物白藜芦醇及其对动物运动能力的影响

本研究以葡萄果茎为主要研究对象,探索了一种通过超声辅助从葡萄中萃取白藜芦醇的先进萃取工艺。同时,通过构建萃取和降解白藜芦醇过程的反应速率常数一级反应动力学模型,研究了萃取时间与回收率、可溶性白藜芦醇、绑定白藜芦醇及降解化合物等组分含量之间的关系,并分析了获得了最佳萃取时间、最大回收率及干物质的量。研究结果显示:与传统乙醇/水溶剂萃取法相比,超声波辅助法萃取白藜芦醇的回收率提高了24%～30%。模拟结果表明:萃取时间对萃取过程中各组分的含量有着显著的影响。当萃取时间为3.48 min时,巨峰葡萄果实茎中白藜芦醇的含量为489.4μg/g干物质,此时回收率最大为79.8%;同时萃取过程中降解化合物含量为83.1μg/g干物质,降解物含量为13.6%。另一方面,赤霞珠葡萄果茎中白藜芦醇的最大回收率和降解化合物的含量分别占总白藜芦醇的80.6%和13.1%,其含量分别为194.8μg/g干物质和31.6μg/g干物质。此外,本研究研究了白藜芦醇对大强度运动大鼠心肌抗氧化能力的影响,结果表明大强度运动后,补充RES可以减少因运动所造成的心肌组织自由基损伤现象。     

白藜芦醇在几种植物中各部位的分布

采用液相色谱研究白藜芦醇在紫斑牡丹、花生和巨峰葡萄几种经济植物各部位的分布情况。结果表明紫斑牡丹籽和果荚的含量远高于花生和巨峰葡萄。花生白藜芦醇含量最低。紫斑牡丹、花生和巨峰葡萄各部位白藜芦醇分布情况如下：紫斑牡丹叶、紫斑牡丹侧枝、紫斑牡丹茎和紫斑牡丹根中均不含有白藜芦醇,而紫斑牡丹籽和紫斑牡丹果荚中含有白藜芦醇,其中紫斑牡丹籽白藜芦醇含量为0.87‰,紫斑牡丹果荚白藜芦醇含量为0.26‰。花生叶、花生胚乳和花生胚芽中均不含有白藜芦醇,而花生侧枝、花生壳、花生皮、花生茎、花生侧根、花生主根中含有白藜芦醇含有白藜芦醇,其含量为花生侧枝3 mg·kg^-1、花生茎11 mg·kg^-1、花生壳12 mg·kg^-1、花生皮15 mg·kg^-1、花生侧根5 mg·kg^-1、花生主根10 mg·kg^-1。经检测发现葡萄肉,葡萄皮,葡萄籽,葡萄蒂四部分中含有白藜芦醇,其中葡萄肉白藜芦醇含量为0.017‰,葡萄皮白藜芦醇含量为0.028‰,葡萄籽白藜芦醇含量为0.005‰,葡萄蒂和其邻近枝白藜芦醇含量为0.12‰。检测说明这几种植物中花生皮、花生壳、葡萄皮、葡萄籽、葡萄蒂、牡丹籽、牡丹荚具有一定的药用价值和经济价值。     

抗性砧木对赤霞珠葡萄叶片白藜芦醇合成过程及含量的影响

为了明确不同抗性砧木对赤霞珠葡萄叶片白藜芦醇含量及其合成过程中前体物质和相关代谢酶活性的影响,分析不同抗性砧木与白藜芦醇合成的关系,以获得提高接穗品种赤霞珠葡萄叶片白藜芦醇含量的抗性砧木。该研究选择弗卡(Fercal)、5C、140R、3309M、3309C、SO4、抗砧3号(Kangzhen3)、5BB为砧木与赤霞珠(CS)葡萄进行嫁接,以赤霞珠自根苗为对照(CK),采用高效液相色谱技术,测定成熟葡萄叶片白藜芦醇以及合成白藜芦醇前体物质苯丙氨酸、肉桂酸、香豆酸含量,并对合成白藜芦醇相关代谢酶苯丙氨酸解氨酶(PAL)、肉桂酸-4-羟化酶(C4H)、4-香豆-辅酶A连接酶(4CL)、过氧化物酶(POD)以及多酚氧化酶(PPO)的活性进行测定。结果表明:(1)不同砧木均能提高接穗赤霞珠葡萄叶片白藜芦醇含量11%~46%。(2)在各砧穗组合中,CS/140R嫁接苗叶片的白藜芦醇含量最高达到18.24μg/g,其合成白藜芦醇前体物质苯丙氨酸和香豆酸含量也最高,分别达到38.61和1.06μg/g。(3)在各砧穗组合中,白藜芦醇相关代谢酶PAL活性以CS/3309C嫁接苗叶片最高;嫁接苗叶片代谢酶C4H和4CL活性均高于赤霞珠自根苗;POD和PPO活性均以CS/Fercal的接穗赤霞珠叶片最强。研究发现,不同抗性砧木能显著提高赤霞珠葡萄叶片白藜芦醇含量,相关代谢酶C4H活性对葡萄白藜芦醇的合成至关重要,PPO活性与葡萄叶片白藜芦醇合成也密切相关,CS/140R是8个砧穗组合中提高赤霞珠葡萄叶片白藜芦醇含量最具优势的砧穗组合。     

夏黑葡萄藤放置过程中化学成分的变化及可能变化机制分析

为分析夏黑葡萄藤在放置过程中化合物的种类、含量变化规律及机制。本研究应用超高效液相色谱仪联用四级杆串联飞行时间质谱仪(UPLC-Q-TOF-MS)在负离子模式下对夏黑葡萄藤中主要化学成分进行定性分析;采用高效液相色谱仪(HPLC)分析夏黑葡萄藤在放置过程中化合物的含量变化趋势。通过液质联用分析方法初步鉴定出夏黑葡萄藤中的黄酮类化合物主要有儿茶素、表儿茶素、槲皮素、槲皮素-3-O-半乳糖苷、petunidin 3-O-glucoside、trans-scirpusin A;芪类化合物为反式白藜芦醇、ε-葡萄素、vitisin B、miyabenol C;苯丙素类化合物为反式咖啡酸。葡萄藤在剪枝后放置过程中,反式白藜芦醇与ε-葡萄素在0～20天左右期间,含量呈显著上升趋势,最高值分别为新鲜样品中的250倍和190倍,从第20天起含量开始降低; vitisin B与miyabenol C为剪枝后放置过程中产生的新化合物,从第10天时含量开始上升,到第50天时含量开始下降。儿茶素、表儿茶素、槲皮素与反式咖啡酸的含量会随着葡萄藤放置时间的延长而持续降低。采用UPLC-Q-TOF-MS可以对葡萄藤中化合物进行快速分析鉴定;葡萄藤在放置过程中逆境胁迫会诱导芪类化合物(反式白藜芦醇、ε-葡萄素、vitisin B、miyabenol C)含量上升,而芪类化合物合成前体物质(trans-scirpusin A)和白藜芦醇合成的竞争物质(儿茶素、表儿茶素、槲皮素)含量则呈下降趋势。     

Transformation of lignins from grape solids during alcoholic fermentation

Conversion of lignins contained in solid parts of Rkatsiteli grapes (crests, seeds, and skin) during alcoholic fermentation by wine yeast in Reader's medium was studied. Various species of wine yeast were used: Saccharomyces oviformis, S. vini Kakhuri 42, S. chodati Teliani 79, and S. uvarum Tsinandali 77. We found that lignins from solid parts of grapes are partially decomposed during alcoholic fermentation, which releases low-molecular-weight aromatic compounds into the medium. A peculiar feature of lignin decomposition during alcoholic fermentation is the formation of reduction products.     

Comparative characterization of polysaccharide fractions in grapes]

Different methods of isolating polysaccharides from grapes were evaluated with respect to the three indictrial grape varieties Traminer pink, Rkatsiteli, Cabernet-Sovinjon. Hot water extration was shown to be the best method in the isolation of water-soluble polysaccharides in primary wine-making. The qualitative and quantitative composition of the isolated polysaccharides was found to depend on the method of isolating polysaccharide fractions. The polysaccharides of grapes were heterogeneous in their molecular weight. The results of periodate oxidation of high molecular weight carbohydrates suggest a branched structure of polymers of water-soluble polysaccharides of grapes.     

Conversion of lignins from solid parts of grapes during alcoholic fermentation

Conversion of lignins contained in solid parts of Rkatsiteli grapes (crests, seeds, and skin) during alcoholic fermentation by wine yeast in Reader’s medium was studied. Various species of wine yeast were used:Saccharomyces oviformis, S. vini Kakhuri 42,S. chodati Teliani 79, andS. uvarum Tsinandali 77. We found that lignins from solid parts of grapes are partially decomposed during alcoholic fermentation, which releases low-molecular-weight aromatic compounds into the medium. A peculiar feature of lignin decomposition during alcoholic fermentation is the formation of reduction products.     

Influence of Berry Heterogeneity on Phenolics and Antioxidant Activity of Grapes and Wines: A Primary Study of the New Winegrape Cultivar Meili (Vitis vinifera L.)

Wine grapes are usually harvested in vineyards when they ripen. However, not all of the berries in a vineyard ripen homogeneously because of different microclimates around the clusters and berries. In this study, the influence of berry heterogeneity on the phenolic content and antioxidant capacity of grapes and wines under a continental monsoon climate was evaluated for a new wine grape cultivar Meili (Vitis vinifera L.). The total phenolic, flavonoid, flavanol, and monomeric anthocyanin contents in the skin and wine significantly increased with grape density; however, there was no significant difference in the seeds between the two lower densities. The highest values of DPPH free radical-scavenging activity, cupric-reducing antioxidant capacity, and hydroxyl radical-scavenging activity in the skin, seed and wine were detected for the densest berries. The sum of individual phenolic compounds in skin, seed and wine increased with berry density, though no significant difference for skin was observed between the two higher density classes. Hence, the chemical components of Meili grapes and wines were positively associated with the berry density at harvest under the continental monsoon climate.     

Applications of NMR micro-imaging to the study of water,lipid, and carbohydrate distribution in grape berries

Summary The technique of nuclear magnetic resonance (NMR) micro-imaging has been applied to the study of water, lipid, and soluble carbohydrate distribution in intact grape berries. Conventional¹H spin echo images reveal details of berry vascular structure, which can be enhanced by suitable choice of imaging parameters. Change in water distribution during drying can also be observed non-invasively. By means of chemical shift imaging methods, it is possible to image separately the distributions of water, lipid, and soluble carbohydrate (glucose and fructose) in selected berries, with an in-plane resolution of 60 m. The technique demonstrated concentration of lipid (oil) in the seeds of intact, mature Shiraz grapes, in a relatively narrow zone in the endosperm, next to its interface with the inner layer of the seed coat, although the lipid zone did not extend entirely around the endosperm perimeter. Carbohydrate, consisting mainly of glucose and fructose in approximately equal proportions, was shown to be evenly distributed in the placental and pericarp tissues of mature grapes. In some cases magnetic field distortions due to the presence of air pockets in seeds of Chardonnay grapes and in seed traces of mature Sultana grapes were also present, leading to an artefactual appearance of localised high sugar in the chemical shift images of these berries.     

不同光质补光对促早栽培‘瑞都香玉’葡萄果实品质的影响

以4年生‘贝达’嫁接的早熟葡萄品种‘瑞都香玉’为试材,研究设施促早栽培条件下,紫外光、蓝光和红蓝光不同光质补光对果实品质的影响,结果表明: 促早栽培节能日光温室内环境属于典型的弱蓝紫光和弱紫外光环境.与对照(未补光)相比,夜间6 h的蓝光和紫外光补光处理可显著加快葡萄果实发育过程中质量和果粒纵横径的增大、果实糖含量的升高以及酸含量的下降,红蓝光效果不明显.果实成熟期紫外光补光处理果实的单粒质量最高,蓝光与红蓝光处理显著高于对照;蓝光补光处理果实葡萄糖、果糖和总糖含量最高,紫外光次之,红蓝光略高于对照.与对照相比,蓝光补光处理可显著加快果实中里那醇、α-萜品醇、橙花醇等萜烯类组分含量高峰的出现,而紫外光、红蓝光补光处理差异较小.果实成熟期蓝光补光处理果实中里那醇、香茅醇等萜烯类物质含量最高,紫外光补光处理里那醇含量较高,香叶醇、己醛、E-2-己烯醛等主要香气物质的含量最高,而红蓝光补光处理里那醇的含量与对照相比有所降低.紫外光、蓝光和红蓝光3种光质补光处理均增加了果实中醛酮类物质的种类及含量.表明蓝光补光处理果实发育最快,成熟最早,糖含量最高,里那醇等萜烯类物质含量高峰出现的时间最早;紫外光补光处理果实的单粒质量最大,主要萜烯类组分含量高;红蓝光补光处理对改善果实品质的效果不明显.     

Impact of diurnal temperature variation on grape berry development, proanthocyanidin accumulation, and the expression of flavonoid pathway genes

Little is known about the impact of temperature on proanthocyanidin (PA) accumulation in grape skins, despite its significance in berry composition and wine quality. Field-grown grapes (cv. Merlot) were cooled during the day or heated at night by +/-8 °C, from fruit set to véraison in three seasons, to determine the effect of temperature on PA accumulation. Total PA content per berry varied only in one year, when PA content was highest in heated berries (1.46 mg berry(-1)) and lowest in cooled berries (0.97 mg berry(-1)). In two years, cooling berries resulted in a significant increase in the proportion of (-)-epigallocatechin as an extension subunit. In the third year, rates of berry development, PA accumulation, and the expression levels of several genes involved in flavonoid biosynthesis were assessed. Heating and cooling berries altered the initial rates of PA accumulation, which was correlated strongly with the expression of core genes in the flavonoid pathway. Both heating and cooling altered the rate of berry growth and coloration, and the expression of several structural genes within the flavonoid pathway.     

Susceptibility of table grape varieties grown in south‐eastern Italy to Drosophila suzukii

Since 2008, Drosophila suzukii, the spotted wing drosophila, has colonized most of the American and European continents, being able to adapt to very different climates. In Italy, this pest has been captured from northern Alpine to southern Mediterranean regions where it can infest a broad range of fruits, including wine grapes. Studies have shown that oviposition levels and developmental rates of D. suzukii on wine grapes are lower than on other berries, although recent observations indicate that grapes may become a suitable host plant in particular conditions. Here, we report, for the first time, the results of a series of no‐choice oviposition experiments using berries of five table grape varieties sampled in the provinces of Taranto and Bari (Apulia region, south‐eastern Italy) during 2013 from both organic and conventional farming systems. The sugar content (SC) and skin hardness of each sample were analysed to assess the influence of these physiological parameters on the susceptibility of table grapes to D. suzukii infestation. A negative correlation was found between the number of eggs laid and berry skin penetration force, whereas there was a positive one between the number of eggs and Brix values, as well as sampling date. In organic grapes, SC and skin hardness of two varieties (“Crimson” and “Scarlotta”) were measured, respectively, higher and lower than in conventional grapes, thus making them more susceptible to pest infestation. The study hence shows that in laboratory conditions D. suzukii is able to heavily infest and develop on table grapes and that susceptibility to its infestation significantly depends on both variety and farming system.     

Changes in Cell Wall Composition during Ripening of Grape Berries

Cell walls were isolated from the mesocarp of grape (Vitis vinifera L.) berries at developmental stages from before veraison through to the final ripe berry. Fluorescence and light microscopy of intact berries revealed no measurable change in cell wall thickness as the mesocarp cells expanded in the ripening fruit. Isolated walls were analyzed for their protein contents and amino acid compositions, and for changes in the composition and solubility of constituent polysaccharides during development. Increases in protein content after veraison were accompanied by an approximate 3-fold increase in hydroxyproline content. The type I arabinogalactan content of the pectic polysaccharides decreased from approximately 20 mol % of total wall polysaccharides to about 4 mol % of wall polysaccharides during berry development. Galacturonan content increased from 26 to 41 mol % of wall polysaccharides, and the galacturonan appeared to become more soluble as ripening progressed. After an initial decrease in the degree of esterification of pectic polysaccharides, no further changes were observed nor were there large variations in cellulose (30–35 mol % of wall polysaccharides) or xyloglucan (approximately 10 mol % of wall polysaccharides) contents. Overall, the results indicate that no major changes in cell wall polysaccharide composition occurred during softening of ripening grape berries, but that significant modification of specific polysaccharide components were observed, together with large changes in protein composition.