红葡萄酒中酚类化合物的快速高效液相色谱分析

阐述了一种新型的可直接而快速分离红葡萄酒中酚类化合物(苯甲酸、黄烷-3-醇、肉桂酸、黄酮醇、花色素)的反相高效液相色谱法。采用的色谱柱可用于低pH环境且能高流速运行，在均含有0.2％三氟乙酸的水和乙腈两相中进行梯度洗脱。为了提高选择性，每种化合物都在其最大吸光度处被检测，从而建立其精密度、线性和灵敏度。尽管这种方法不能检测酒中所有组分，但适用于主要成分的测定和对特殊类别酚类化合物总量的定量分析。     

固相萃取-高效液相色谱法同时测定葡萄酒中没食子酸等8种多酚类化合物

建立了固相萃取.高效液相色谱光电二极管阵列检测法测定葡萄酒中没食子酸等8种多酚类生物活性化合物的方法.并用此方法测定了市售的7种葡萄酒中该8种生物活性物质的含量.实验确定了葡萄酒样品中的没食子酸等物质的固相萃取方法,通过优化萃取条件,有效的去除了葡萄酒中大量干扰成分.采用HypersilC18柱(250mm×4.6mm,i.d.5μm)分离.以乙腈-0.3%乙酸为流动相,线性梯度洗脱,以保留时间和特征光谱对分离出的组分予以定性确证,用峰面积进行定量.8种组分的质量浓度与其峰面积在一定的范围内有良好的线性关系,相关系数为0.9982～0.9999,8种组分的平均回收率为83.9%～103.7%(相对标准偏差为1.6%～4.6%),检测限为0.2～1.5mg/L.对市售的7种葡萄酒的检测结果表明,多酚类物质作为葡萄酒中重要的生物活性成分,其含量与葡萄酒的酿造方式,葡萄品种,葡萄产地有密切的关系.该方法简便、快速、灵敏,也适用于其它复杂体系中没食子酸等8种生物活性的成分分析.     

固相萃取-高效液相法测定黄酒中多酚

为了寻找一种更高效、富集能力更强,更具有针对性的前处理方式,解决黄酒多酚测定时存在的杂质多、目标物含量低、定量不准确的问题,采用固相萃取小柱对黄酒进行前处理,就流动相条件、固相萃取小柱类型、洗脱剂类型、洗脱剂体积等因素对9种多酚的回收率影响做了评价比较,并运用该方法对不同甜型的绍兴黄酒中多酚质量浓度进行精确测定,结果表明:采用Poly-Sery HLB SPE小柱,甲醇为洗脱剂,洗脱体积为3倍上样体积时9种多酚回收率最高,均在87.3%～103.8%之间,相对标准偏差小于3.2%。不同甜型的绍兴黄酒中多酚以儿茶素和丁香酸为主,干型黄酒、半干型黄酒中多酚质量浓度低于甜型黄酒和半甜型黄酒。该方法具有快速、简便、准确的优点,可用于黄酒等酒类的多酚测定。     

Phenolic and Anthocyanin Profile of Valea Calugareasca Red Wines by HPLC-PDA-MS and MALDI-TOF Analysis

The quality of red wines is given by phenolic compounds and anthocyanins and is associated with colour, taste and therapeutic effects on human health. This work aims to provide a detailed profile of phenolic compounds and anthocyanins that are found in five red wine samples from Dealu Mare-Valea Calugareasca region. The phenolic and anthocyanin profiles of the red wine samples were determined by high-performance liquid chromatography-photodiode array-mass spectrometry and matrix-assisted laser desorption/ionisation–time of flight, respectively. The results obtained showed that Feteasca Neagra had the highest content of phenolic compounds followed by Pinot Noir while the preponderant compound was gallic acid. Amongst anthocyanins, malvidin was found to be the major compound and the highest anthocyanin content was found also for Feteasca Neagra wine. A simple high-performance liquid chromatography-photodiode array-mass spectrometry method was developed, optimised and applied for the quantification of phenolic compounds in red wine samples from Dealu Mare-Valea Calugareasca region. In the same time, a rapid matrix-assisted laser desorption/ionisation–time of flight method that does not need sample preparation was applied for the identification of anthocyanins. Moreover, the phenolic and anthocyanin composition of red wines from Dealu Mare-Valea Calugareasca region is reported for the first time. The phenolic and anthocyanin profile determination will be beneficial for the Romanian winemakers to produce high-quality red wines.     

Comparison and Chemometric Analysis of the Phenolic Compounds and Organic Acids Composition of Chinese Wines

Characteristics of 106 wines from 5 major grape varieties and 3 typical geographic regions in China were investigated by means of profiling of organic acids and phenolic compounds analysis. An ultra‐performance liquid chromatography method was developed and thus, large number of samples could be determined in a quick and reliable way. The results showed that different origins and varieties were characteristic of various profiles of organic acid and phenolic compounds. In order to investigate possible correlation between organic acids and phenolic compounds content and grape variety and/or geographical origin, analysis of variance and linear discriminant analysis (LDA) were conducted. A satisfactory LDA result for red wines according to geographic origin was obtained, in which the correct classification was 100% and the leave‐one‐out validation accuracy was 90%. The corresponding results of white wines were 91% and 86%, respectively. When LDA was processed, according to grape varieties, the proportionality of successfully classified wines was 96%, while the leave‐one‐out validation accuracy was 94%. The organic acids and phenolic compounds profiles were useful in the classification of Chinese wines according to grape variety and geographic origin.     

Aromatic Compounds in Wines Produced During Fermentation: Effect of Three Red Cultivars

The aromatic compounds produced during the fermentation of the red grape cultivars Caiño Tinto, Caiño Longo, and Caiño Bravo were analysed by gas chromatography (FID) on the wines of 2002 and 2003 vintages. In both years, significant differences (p < 0.001) were observed between the wines with respect to the concentrations of aromatic compounds. Caiño Longo wines had the highest concentrations of acetates and esters. The concentrations of ethyl ester and acetates in Caíño Bravo wines were comparatively very low. Principal components analysis confirmed these results: the wines made from the different cultivars and the vintages were clearly different.     

正交信号校正方法在啤酒酒精度近红外光谱分析中的应用

以啤酒酒精度的快速测定为研究对象,对原始光谱分别进行一阶导数、二阶导数、正交信号校正(OSC)等预处理方法后,用偏最小二乘法(PLS)建立了啤酒酒精度校正模型,然后用所建模型对预测集进行预测.结果表明,使用OSC预处理方法后,PLS主成分数为2,验证集预测均方差和平均相对误差分别为0.095%和1.002%,效果最佳.在建立定量校正模型前,对光谱进行OSC预处理方法滤除了与浓度阵无关的光谱信号,减少了建立模型所用的主因子数,进一步提高了校正模型的预测能力和稳健性.     

超高效液相色谱串联质谱法测定樱桃酒中的5种酚酸

建立了超高液相色谱-串联四级杆质谱联用(UPLC-MS/MS)技术同时检测樱桃酒中没食子酸、4-羟基苯甲酸、绿原酸、香草酸和咖啡酸5种生物活性酚酸的方法。采用Waters Acquity UPLC BEH色谱柱(100×2.1mm,1.7μm),流动相为甲醇-0.1%甲酸,在梯度条件下进行分析,分析物在负离子模式下用保留时间和质谱信息进行定性,峰面积进行定量,并评价其定量分析的精密度、线性和检出限。结果显示,回收率在82.3%～110.8%之间;相关系数r>0.99,线性关系良好;精密度的相对标准偏差RSD<2.0%,检出限为0.020～0.050mg/L,说明该方法简便、快速、准确、灵敏,可用于樱桃酒中酚酸的检测。此外,实验采用SPSS17.0软件对樱桃酒的理化指标和5种酚酸进行了简单相关分析。     

Relationship between Sensory Perception,Volatile and Phenolic Components in Commercial Spanish Red Wines from Different Regions

Polyphenols are an important fraction of the non-volatile components in the red wine matrix, and they are influenced in quantity and composition at all stages from the grape growing conditions until the time the wine is consumed. Evidence of their interaction with volatiles has been found, and this should affect wine flavour. A range of 12 commercial Spanish red wines from different regions and ages was analysed for their sensory properties, volatile composition in solution and headspace, and their non-volatile phenolic components. Maturation was the most important effect on sensory perception, while the chemical data showed also individual differences between the wines and their regions of production. Headspace volatiles and the phenolic fraction showed better correlations with the sensory perception, but volatiles in solution did not give a good prediction, though there were changes related to maturation. Some flavour components showed changes in their volatile behaviour in the matured wines. This supports the hypothesis that changes in the behaviour of the volatile fraction are related to the evolution of phenolic compounds.     

灭活酵母对干红葡萄酒酚类物质及其抗氧化活性的影响

以河北省昌黎县华夏长城葡萄园的赤霞珠葡萄所酿干红葡萄酒为研究对象,设计4种不同的试验处理,测定葡萄酒中酚类物质含量及其抗氧化活性,研究灭活酵母对葡萄酒中酚类物质含量及其抗氧化活性的影响。试验结果显示,第5天添加灭活酵母3 g/L(处理1)的葡萄酒中总酚、总花色苷和总单宁的含量最高;单体酚含量测定时,第25天添加灭活酵母3 g/L(处理3)的葡萄酒中咖啡酸、绿原酸、芦丁、(+)-儿茶素、鞣花酸和没食子酸含量最高;不同处理下样品的总还原能力、DPPH·清除率和ABTS~+·清除率都有不同程度的提高。因此,灭活酵母能提高赤霞珠干红葡萄酒中酚类物质的含量,增强其抗氧化活性。     

Volatile Compounds in Red Wines Processed on an Industrial Scale by Short Pre-fermentative Cold Maceration

Nero d’Avola and Shiraz grapes were subjected to pre-fermentative cold maceration at 4°C for about 24 h in industrial winemaking, in order to evaluate the effects of the pre-treatment on aroma profile. The volatile compounds were identified by gas chromatography-mass spectrometry and grouped into 14 chemical families 4 and 9 months after bottling. Principal components analysis (PCA) plots of the volatile compounds showed clear separation among wines from the Shiraz and Nero d’Avola varieties. For instance, Shiraz wines were characterized along the PC1 axe by esters of organic acids, norisoprenoids and C₆ alcohols, while Nero d’Avola wines were characterized by acetates and monoterpenic oxides and diols. Moreover, pre-treated samples showed significant (p?<?0.05) changes in volatile compounds belonging mainly to ethyl esters of straight chain fatty acids, acetates and norisoprenoids. The sensorial analysis showed that cold maceration contributed to development of a different aroma profile during bottle maturation if applied on Nero d’Avola or Shiraz variety.     

Discriminant Analysis of Selected Edible Fats and Oils and Those in Biscuit Formulation Using FTIR Spectroscopy

Recently, lard adulteration has highlighted the importance of checking raw materials and food products in order to assure their authenticity. Discriminant analysis (DA) using selected frequency regions (3,050?C2,800, 1,800?C1,600, and 1,500?C650 cm^?1) was exploited for the classification of lard and other commercial vegetable oils and animal fats. As a result, the Cooman plot showed that all vegetable fats/oils and animal fats, including lard, are clustered in a distinct group. DA was also employed to assign real food samples, in particular biscuit, into one of two groups. In addition, DA is a very useful means for Halal screening technique in order to enhance the Halal authentication process.     

Total Phenolic Compounds, Flavonoids, and Radical Scavenging Activity of 21 Selected Tropical Plants

ABSTRACT:  Free radical scavenging activity of 21 tropical plant extracts was evaluated using 1,1-diphenyl-2-picrylhydrazyl assay (DPPH). Total phenolic compounds and flavonoids were determined using Folin–Ciocalteu and HPLC, respectively. Results of the study revealed that all the plants tested exhibited excellent antioxidant activity with IC₅₀ in the range of 21.3 to 89.6 μg/mL. The most potent activity was demonstrated by  Cosmos caudatus  (21.3 μg/mL) and  Piper betle  (23.0 μg/mL) that are not significantly different than that of     -tocopherol or BHA.  L. inermis  extract was found to consist of the highest concentration of phenolics, catechin, epicatechin, and naringenin. High content of quercetin, myricetin, and kaempferol were identified in  Vitex negundo ,  Centella asiatica , and  Sesbania grandiflora  extracts, respectively. Luteolin and apigenin, on the other hand, were found in  Premna cordifolia  and  Kaempferia galanga  extracts. Strong correlation ( R  = 0.8613) between total phenolic compounds and total flavonoids ( R  = 0.8430) and that of antioxidant activity of the extracts were observed. The study revealed that phenolic, in particular flavonoids, may be the main contributors to the antioxidant activity exhibited by the plants.
Practical Application: Potent antioxidant from natural sources is of great interest to replace the use of synthetic antioxidants. In addition, some of the plants have great potential to be used in the development of functional ingredients/foods that are currently in demand for the health benefits associated with their use.     

Stability of Individual Phenolic Compounds and Antioxidant Activity During Storage of a Red Wine Powder

The addition of maltodextrin DE 10 to red wine (Cabernet Sauvignon) followed by freeze-drying allowed to obtain a free-flowing (dealcoholized) wine powder (WP) having a phenolic concentration about 3.6 times higher than the original liquid red wine. The powder, having a water activity (a _w) of 0.053 and 0.330 was stored at 28 °C and 38 °C and the content of ten different phenolic compounds was determined by HPLC. Caftaric acid, quercetin 3-glucoside, caffeic acid, gallic acid and resveratrol contents in the WP stored at 28 °C and 38 °C, remained almost constant during 70 days of storage, while epicatechin gallate, catechin, malvidin 3-G and epicatechin showed slight losses (about 15–25 %) during storage. On the contrary, epigallocatechin experienced a strong loss of concentration (around 61 % loss) during storage at the same conditions. A moderate decrease of antioxidant activity, determined by free radical scavenging capacity of the 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH*) and ferric reducing antioxidant power (FRAP) was observed along storage. This decrease was more important at higher temperature (38 °C) and higher a _w (0.33). These results would allow the feasibility of using this WP as a healthy ingredient in alcohol-free powder drinks.     

枇杷酚类物质及其生物活性研究进展

枇杷富含酚类物质,目前已鉴定酚酸(羟基肉桂酸和羟基苯甲酸)和黄酮类(黄酮醇、黄烷酮、黄烷醇和黄酮木脂素)等物质50余种。不同组织、品种、发育阶段和采后处理方法均能影响酚类物质组成和含量。枇杷酚类物质有抗氧化、消炎、抗糖尿病、细胞保护、抑菌等生物活性。本文对枇杷酚类物质组成、含量分布和生物活性进行综述。     

Carotenoid Profile in Grapes Related to Aromatic Compounds in Wines from Douro Region

ABSTRACT The aim of this work was to characterize 8 representative grape varieties of the Douro Region using the carotenoid profile as it relates to aromatic compounds in the respective wines. Some other analyses, such as the determination of sugar, probable alcohol, pH, and total acidity, were also performed in an attempt to understand in which way the evaluated characteristics influenced by grape variety could contribute to the wine aroma. For the 3 y of the study, grape varieties with higher concentrations of carotenoids (Touriga Femea, Tinta Amarela, and Tinta Barroca) have lower values of free norisoprenoids, even with exceptions (Touriga Femea). Conversely, grape varieties with lower concentrations of carotenoids (Touriga Nacional, Sousao, and Tinto Cao) appear to have higher contents of free norisoprenoids, namely b‐ionone for Touriga Nacional and vitispirane and 1,1,6‐trimethyl‐1,2‐dihydronaphthalene (TDN) for Sousao and Tinto Cao. Touriga Nacional, followed by Touriga Femea, was the wine variety with the highest values of total free terpenols (linalol, a‐terpineol, nerol, and geraniol), the presence of which is responsible for the floral aroma.     

Analysis and Differentiation of the Volatile Compounds in Red and White Wines Using Desiccated Headspace Gas Chromatography-Mass Spectrometry Coupled with Chemometrics

A well-tailored method for the fingerprinting analysis of volatile compounds in wines has been developed. Based on the complete hydrate formation between sample solvent and anhydrous salt, an in situ desiccated sampling of volatile compounds into GC-MS was achieved, which can be directly applied to the aqueous wine sample without any pretreatment. By this means, the volatile compounds in 17 wine samples have been successfully detected. To explore the common features underlying the fingerprinting differences in volatile compounds between red and white wines, PCA and PLS-DA were successively performed on 18 peaks and 10 peaks of volatile compounds in the wine samples, and good clustering was obtained for the classification of the two kinds of wines. The results showed that five characteristic components, i.e., 2-hydroxy-propanoic acid ethyl ester, butanedioic acid monomethyl ester, 4-oxo-pentanoic acid ethyl ester, 1-dodecene, and 1,2,3-trimethoxy-5-methyl-benzene, were found to be quite different in their contents between red and white wines among the other volatiles, which, to some extent, may take responsibility for the differences in their volatile aroma. This work will provide a useful tool and valuable guidance for elucidating the chemical fingerprinting differences in organoleptic quality among different wines.     

酚酸类物质对杨梅发酵酒贮藏期间色泽和挥发性风味物质的影响

为研究杨梅发酵酒贮藏过程中色泽及风味变化,本实验采用气相离子迁移谱仪、色差计、电子舌和感官评价方法探究酚酸类物质对杨梅发酵酒的辅色作用、挥发性风味变化和感官指标的影响.结果表明:单宁酸、阿魏酸、芥子酸均对杨梅发酵酒具有辅色作用,减缓了a*、C*值和ΔE*值的变化趋势,明显增强了杨梅发酵酒贮藏期间色泽稳定性;通过气相离子...     

Apple Polyphenol Oxidase Activity in Relation to Various Phenolic Compounds

SUMMARY— The role of various polyphenolic compounds in oxidations catalyzed by apple polyphenol oxidase (PPO) was investigated. Quercetin, quercitrin, rutin, cyanidin chloride, phloroglucinol, and resorcinol were neither substrates nor inhibitors of apple PPO. Phloroglucinol and resorcinol increased the rate of PPO catalyzed oxidation of chlorogenic acid.
Esculetin and dihydroquercetin were found to be substrates of PPO. No synergistic effect was detected in the browning rates of an esculetinchlorogenic acid mixture or a dihydroquercetin-chlorogenic acid mixture. Ferulic acid, fisetin, and p-coumaric acid were generally non-competitive inhibitors, although ferulic acid inhibited competitively in one test. It was hypothesized that the conjugated system in flavones prevents these compounds from being apple PPO substrates.