Mass spectrometric evidence for the formation of pigmented polymers in red wine

The polymeric materials (wine tannin) were isolated from a three-year-old Pinot Noir using Toyopearl TSK HW 40-F size exclusion chromatography. The wine tannin was analysed by reversed-phase and gel permeation high performance liquid chromatography, UV-Vis spectrophotometry and mass spectrometry. Analysis by gel permeation chromatography indicated that the isolate was in large part polymeric, and also indicated the presence of pigmented material monitored at a wavelength of 520 nm. Acid-catalysis in the presence of phloroglucinol indicated that the wine tannin contained 45% w/w known proanthocyanidin material. The wine tannins gave a complicated mass spectrum featuring a large number of intense signals derived from proanthocyanidins and, to a much lesser extent, a series of ions corresponding to masses consistent with direct condensation products of an anthocyanin with proanthocyanidins. The degree of polymerisation by mass spectrometry was detected to be as high as an octamer composed of an anthocyanin combined with a proanthocyanidin heptamer. Based upon current evidence, the anthocyanin was proposed to be bound from the C-6/8 or C-4 positions of the anthocyanin to the respective electrophilic or nucleophilic centre of the proanthocyanidins. Only the species with the C-6/8 position of the anthocyanin linked with the proanthocyanidins seemed to be pigmented. Under acid-catalysed conditions, an increase in malvidin-3-glucoside was observed, suggesting that the non-pigmented form is possibly converted to the pigmented flavylium form. This is the first mass spectrometric evidence confirming the existence of pigmented polymers with an extension to octamers in wine.     

Formation of vitisin A during red wine fermentation and maturation

During alcoholic fermentation the formation of vitisin A occurred mainly in the period between 20% and 85% glucose utilisation, when the concentrations of the precursors, malvidin-3-glucoside and pyruvic acid were at a maximum. The maximum rate of vitisin A synthesis of 11 mg/Lh occurred when 57% of glucose had been utilised and 440 mg/L malvidin-3-glucoside, 114 mg/L pyruvic acid and 3.1 mg/L measured oxygen were present. During maturation, production of vitisin A appeared to be linked with the availability of a suitable oxidant. Synthesis of vitisin A continued for approximately 6 months of maturation in air-tight bottles while the precursors were available. In wines that underwent malolactic fermentation, the malolactic bacteria consumed pyruvic acid and thereby limited the production of vitisin A. At the end of a 12 month maturation period, the concentration of vitisin A declined in wines made without any malolactic fermentation, even though malvidin-3-glucoside and pyruvic acid were still present. This indicated that there was a shortage of a suitable oxidant required to complete the reaction.     

HPLC法测定复方保健酒中人参皂苷和西红花苷的含量

采用高效液相色谱仪建立测定复方保健酒中人参皂苷Rg₁、人参皂苷Rb₁、人参皂苷Rb₂、人参皂苷Rc、西红花苷I、西红花苷II含量的方法。结果表明,最佳测定条件为采用Agilent SB-Aq色谱柱(4.6 mm×250 mm,5μm),以乙腈-水为流动相梯度洗脱,流速1.0 mL/min,柱温30℃,人参皂苷的检测波长203 nm,西红花苷的检测波长为440 nm,进样量10μL。人参皂苷Rg₁、人参皂苷Rb₁、人参皂苷Rb₂、人参皂苷Rc、西红花苷I、西红花苷II在各自浓度范围内线性关系良好(R≥0.999 9),平均加标回收率97.83%～101.72%,精密度试验结果相对标准偏差(RSD)0.43%～1.85%。实验结果表明该方法操作简单,精密度和准确度高,重复性好,可用于复方保健酒中人参皂苷和西红花苷含量测定。     

高效液相法同时测定葡萄酒中3种防腐剂和2种甜味剂

建立了一种高效液相色谱法同时测定葡萄酒中3种防腐剂（苯甲酸、山梨酸、脱氢乙酸）和2种甜味剂（安赛蜜、阿斯巴甜）。样品去除乙醇后,加入乙酸锌与亚铁氰化钾溶液处理,用C18色谱柱分离,甲醇和乙酸铵（0.02 mol/L）溶液进行梯度淋洗,流速1.0 mL/min,测定波长为230nm和209 nm,进样量20μL。在此条件下,5种组分能够完全分离,呈现良好的线性关系。加标回收率87.3%~110.0%,相对标准偏差为0.5%~3.6%。     

反相高效液相色谱法测定黄酒中的草酸

该文建立了一种利用反相高效液相色谱法测定黄酒中草酸的方法,该方法以邻苯二胺为衍生剂,在高温酸性条件下与草酸反应,生成强紫外吸收化合物——2,3-二羟基喹喔啉,对其检测的最优色谱条件是:Dionex Acclaim 120 C18柱(4.6×250 mm,5μm);以甲醇和0.1mol/L乙酸铵(15:85 v/v)为流动相;流速1.2mL/min;检测波长314nm;柱温25℃。该方法测定黄酒样品中草酸的回收率为91.40%~103.70%,相对标准偏差小于9.30%。该方法简便、准确,适合测定黄酒中草酸的含量。     

高效液相色谱法同时测定黑米酒中11种酚类物质

建立了高效液相色谱测定黑米酒中11种酚类化合物的方法。采用Venusil C18色谱柱(250mm×4.6mm,5μm)分离,流动相为50%乙腈和超纯水,分别加1%乙酸,采用梯度洗脱,流速为1.0mL/min,进样量20μL,柱温30℃,检测波长260nm、320nm。各组分的质量浓度与其峰面积具有良好的线性关系,相关系数均大于0.996,且11种酚类物质在45min内得到了较好分离。方法回收率为83.5%~105.1%,相对标准偏差为1.3%~3.3%。该方法可用于米酒中黄酮、酚酸类化合物的定量分析。     

Analysis of grape and wine tannins: Methods, applications and challenges

Tannins are polyphenolic secondary metabolites, which can be found in many higher plants and are identified by their ability to complex with and precipitate proteins. This key property is believed to be responsible for the mouth‐feel and astringency caused by wine tannins. The analysis of tannins is of interest to practitioners in a diverse range of fields, including chemistry, pharmacology, food science, animal nutrition, ecology and plant physiology. There is a desire within the Australian wine industry to exploit objective tannin measures to complement human sensory assessment for style and quality specifications. This review, therefore, concentrates on grape‐derived condensed tannins, also known as proanthocyanidins, and wine tannins formed from grape tannins. We summarise recent advances with the development of analytical methods for the quantification of tannins, review techniques for the structural characterisation of tannin molecules and emphasise the need to refine these techniques.     

高效液相色谱法测定黄酒中纽甜的不确定度评定

建立了高效液相色谱法测定黄酒中纽甜含量不确定度的分析方法。依据JJF 1059.1-2012《测量不确定度评定与表示》及CNAS-GL06：2006《化学分析中不确定度的评估指南》中不确定度评定的基本程序,建立数学模型,分析高效液相色谱法测定黄酒中纽甜含量过程中引入的各测量不确定度分量,计算得到测量结果的合成标准不确定度和扩展不确定度。结果表明：影响检测结果不确定度的因素主要是校准曲线拟合求浓度,其次是样品前处理及测定和标准工作溶液的配制,相对标准不确定度分别为0.016 13、0.011 27、0.007 90。其中样品前处理及测定因素中贡献大的分量是通过样品重复性引入的相对不确定度,相对标准不确定度为0.009 61。     

干红葡萄酒中顺、反白藜芦醇及其苷的HPLC分析

采用PolarisC18-A色谱柱(100×2.0mmid,3μm),PhenomenexC18预柱(4×3.0mmid),乙腈、水为流动相,梯度洗脱,流速0.4mL/min,柱温40℃,荧光检测器:激发波长334nm;发射波长404nm,直接进样,同时分离了顺、反白藜芦醇及其苷。结果显示:在选定色谱条件下,白藜芦醇及其苷的顺、反异构体线性关系良好,加样平均回收率为90.7%￣98.5%;相对标准偏差为0.51%￣1.68%。该方法精密度好,结果可靠,适合于红酒中顺、反白藜芦醇及其苷的定量分析。     

Amelioration of smoke taint in wine by reverse osmosis and solid phase adsorption

Background and Aims: Wines made from grapes harvested from vineyards exposed to bushfire smoke can exhibit objectionable ‘smoky’, ‘cold ash’, ‘medicinal’ and ‘ashy’ aroma and flavour characters. This study evaluated a combined reverse osmosis and solid phase adsorption process as a potential amelioration method for the treatment of smoke‐tainted wines. Methods and Results: Smoke‐tainted wines were treated using either pilot or commercial scale reverse osmosis systems and the chemical composition and sensory properties of wine compared before and after treatment. The concentrations of smoke‐derived volatile phenols, including marker compounds, guaiacol and 4‐methylguaiacol, decreased significantly with treatment. As a consequence, diminished smoke‐related sensory attributes enabled treated wines to be readily differentiated from untreated wines. However, the taint was found to slowly return with time, likely because of hydrolysis of glycoconjugate precursors, which were not removed during the treatment process. Conclusions: Reverse osmosis and solid phase adsorption reduced the concentration of smoked‐derived volatile phenols and improved the sensory attributes of smoke‐tainted wines. Significance of the Study: This is the first study to evaluate the amelioration of smoke taint in wine using reverse osmosis and solid phase adsorption.     

Sensory evaluation of black pigmented rice (Oryza sativa cv. Poireton) wine fortified with probiotic Lactobacillus acidophilus ATCC 4356 and Lactobacillus sakei ATCC 15521 using fuzzy logic

Rice wine was prepared in the laboratory from a black pigmented rice (cv. Poireton) using standardized methodology. The wine was fortified with the probiotic strains Lactobacillus acidophilus ATCC 4356 and Lactobacillus sakei ATCC 15521 and allowed to undergo a storage period of 28 days at 4°C. These rice wines were compared with a commercial wine used as a standard reference wine. A panel consisting of 30 judges performed the sensory evaluation. The scores obtained were based on the quality attributes of colour, taste, aroma and alcoholic strength. Analysis of the sensory scores and ranking of the different samples were performed using fuzzy analysis. The quality attributes were also ranked according to their importance in the overall acceptability. Colour and alcoholic strength were accorded the highest importance, compared with aroma and taste, as quality attributes. The rice wines were rated as ‘not satisfactory’, ‘fair’, ‘medium’, ‘good’ and ‘excellent’ on the sensory scale. Out of the wines prepared, black pigmented rice wine fortified with L. acidophilus was the most acceptable and was ranked as ‘good’, which was also at par with the commercial wine. On the other hand, black pigmented rice wine fortified with L. sakei and black pigmented rice wine fortified with L. acidophilus and L. sakei were ranked in the ‘satisfactory’ category followed by the unfortified wine ranked in the ‘fair’ category. Copyright © 2015 The Institute of Brewing & Distilling     

HPLC法同时测定葡萄和葡萄酒中6种基本花色苷

该研究建立了高效液相色谱法同时测定葡萄和葡萄酒中6种基本花色苷的检测方法。样品经无水乙醇/盐酸/水（2∶1∶1, V/V）提取,采用Agilent-ZORBAX SB-C18色谱柱（250 mm×4.6 mm, 5 μm）为固定相,流动相A（乙腈）和B（0.1%磷酸水溶液）梯度洗脱,流速0.8 mL/min,检测波长525 nm。在该色谱条件下,6种花色苷在30 min内得到了很好的分离效果,其含量与峰面积呈现良好线性关系（R＞0.999 3）,且回收率为82.2%～93.3%、精密度好（RSD＜5.0%）。该方法方便、快速,能够实现对葡萄和葡萄酒中6种花色苷物质的定性及定量检测。     

HPLC法测定桃不同品种果实中花色苷组成和含量

目的： 用高效液相色谱法测定桃不同品种果实中花色苷组成和含量。方法： 色谱柱为C1 8柱(150mm×4.6mm,5μm),流动相为乙腈：4%磷酸溶液(V/V=12:88,pH2),检测波长520nm,流速0.8mL/min,进样量20μL,柱温30℃。结果：桃3个品种果实中主要含有1种花色苷：花青素-3-葡萄糖苷,花青素-3-葡萄糖苷在0.4～100μg/mL内线性关系良好(R=0.9992),低、中、高质量浓度的平均回收率为85.7%、89.4%、91.2%。红、黄、白肉桃果肉中的花青素-3-葡萄糖含量分别为103.7、30.6、21.5mg/kg。结论：本方法操作简单,结果准确可靠,重复性好,可作为桃果实中花青素-3-葡萄糖苷的定量分析方法。     

Interactions of Oligomeric Procyanidins in Model Wine Solutions Containing Malvidin-3-Glucoside and Acetaldehyde

Interactions of grape seed flavanols, dimeric, galloylated dimeric and trimeric procyanidins with malvidin-3-glucoside and acetaldehyde were studied in wine-like model solutions. Malvidin-3-glucoside and oligomeric procyanidins reacted very slowly, with eventual formation of yellow xanthylium salts. The concentrations of malvidin-3-glucoside and oligomeric procyanidins decreased faster in the presence of acetaldehyde and the colour augmentation with shift towards violet was attributed to the formation of new coloured compounds, detectable by HPLC and linked at different positions by CH₃CH bridges. The rate of loss of procyanidins in the presence of malvidin-3-glucoside and acetaldehyde varied according to the complexity of the components. Monomeric (+)-catechin and (-)-epicatechin reacted more slowly than dimer procyanidins B₁, B₂ and B₃ while trimer C₁ (epicatechin 4β→8 epicatechin 4β→8 epicatechin) presented the highest degradative reaction rate.     

Determination of red wine flavonoids by HPLC and effect of aging

A new method for simultaneous determination of 10 flavonols and 2 flavones by high performance liquid chromatography was developed in this paper. The identified compounds contained quercetin, kaempferol, myricetin, rhamnetin, isorhamnetin, quercetrin, rutin, morin, galangin, fisetin, apigenin and luteolin. The chromatographic separation of these flavonoids was performed in a single run by using the mobile phase gradient elution of acetonitrile–methanol–water mixture (1% tetrahydrofuran, THF) at 20 °C, with the flow rate at 1.0 ml/min and the detection wavelength at 360 nm. With direct injection of wine samples, seven red wine samples, differing in their origin of producing places and time, were analyzed for flavonoids content by this method. The results showed the presence of myricetin, luteolin, quercetin, kaempferol, isorhamnetin and galanin. Additionally, the changes of flavonoids in red wines stored in the three types of oak barrels with aging time were investigated, which indicated that the component of flavonoids in red wine is related to wine aging greatly. These provide a substantial basis for the further research on control of flavonoids during winemaking.     

葡萄皮渣中三种主要花色苷的优化提取

以HPLC为检测手段,考察分析了葡萄皮渣中的三种主要花色苷:二甲花翠素葡萄糖苷(Mv3-glu)、二甲花翠素乙酰葡萄糖苷(Mv3-acet-glu)、二甲花翠素反式香豆酰葡萄糖苷(Mv3-coum-glu),建立了快速提取方法。实验以乙醇为提取溶剂,通过单因素实验和正交实验设计,研究了三种花色苷的最佳提取条件。实验表明,液料比1.5:1(mL/g),温度70℃,提取时间40min,提取液乙醇中含1.0%盐酸(v/v),一次提取,即可快速提取出皮渣中的三种主要花色苷。     

采用高效液相色谱法分析荔枝酒中的酚类物质

选用乙酸乙酯作为荔枝酒酚类化合物的萃取溶剂,通过对HPLC洗脱条件的摸索,建立了HPLC同时分离荔枝酒中40多种组分的反相色谱条件。结合标准品保留时间比对和LC-MS-MS分析,准确定性了其中的(-)-表儿茶素、原花青素B2、没食子酸和芦丁等4种酚类物质,并在此基础上建立了这4种酚类化合物的HPLC定量测定方法,回收率均在85%以上。该技术为进一步研究荔枝酒的褐变问题提供了有效的分析手段。     

HPLC法快速检测黑糯米酒中有机酸含量

建立了应用高效液相色谱（HPLC）法对黑糯米酒中草酸、酒石酸、丙酮酸、苹果酸、α-酮戊二酸、乳酸、乙酸、柠檬酸、焦谷氨酸和琥珀酸的含量进行快速检测的方法。结果表明,检测器为二极管阵列检测器,ZORBAX SB-Aq色谱柱（250 mm×4.6 mm,5 μm）,柱温35 ℃,检测波长210 nm,流动相为0.03 mol/L的磷酸二氢钠溶液,pH值为2.90,在0～4.00 min,流速为1.0 mL/min;4.00～10.00 min流速为0.30 mL/min;10.00 min后流速为1.0 mL/min。黑糯米酒中10种有机酸均能在10 min内得到很好分离。标准曲线相关系数0.999～1.000,重复性试验相对标准偏差（RSD）为0.15%～0.87%,精密度实验RSD为0.024%～0.543%,检出限为0.015～0.219 mg/L,样品加标回收率为94.39%～104.73%。故此方法适用于快速测定黑糯米酒中10种有机酸含量。     

高效液相色谱-荧光法测定红酒中的黄酮

实验建立了高效液相色谱法(HPLC)测定红酒中的槲皮素,桑色素和山奈酚的含量的方法。采用Polaris C18(2.0×100mm,3μm)色谱柱,柱温为60℃,流动相:A相0.1mol/LHAc,B相为乙腈,流速为0.2 mL/min,梯度淋洗,柱后衍生,激发波长438nm,发射波长483nm。结果:黄酮的线性范围为0.25mg/L~4.0mg/L。平均加样回收率89.7%~95.1%,相对标准偏差为1.37%~-2.98%。该方法简便、准确,可用于天然产物中槲皮素,桑色素和山奈酚含量的测定。