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。     

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.     

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.     

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.     

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。     

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.     

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.     

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.     

葡萄酒中酚类物质抗氧化活性及构效关系

<正>酚类物质是芳香环上连有一个或多个羟基的低分子量有机化合物,其不但决定了葡萄酒的口感、色泽、贮藏寿命及稳定性,而且具有很强的抗氧化活性。葡萄酒中酚类物质对机体的防御作用归功于它特有的化学结构——酚羟基结构,它们具有供电子作用,通过提供活泼的氢捕捉机体内活性氧等自由基,阳断了自由基对机体的损伤。另外,葡萄酒中酚类物质也具有络合过渡金属离子能力、激活抗氧化酶的活性、减少α-生育酚自由基及降低氧化酶活性的能力。然而,尽管现在不同实验模式已证实了酚类化合物的这种多功效作用,但对于它们的构效关系的描述还不尽一致,因此,本文总结了酚类化合物(以类黄酮酚为例,见图1)在自由基清除作用和金属离子络合作用中关键的化学结构特征及影响,以旨为葡萄酒中酚类物质构效关系研究提供理论参考。     

果蔬酚类物质抗氧化活性研究

采用基于不同机理的抗氧化方法对果蔬中常见的酚类物质单体,包括黄烷酮、多甲氧基黄酮、黄酮醇、酚酸等活性成分行了较全面的评价。结果显示酚类物质的抗氧化能力与其结构有密切关系。对天然产物或抗氧化剂的抗氧化能力的评价应该采用至少两种机理不同的抗氧化方法进行测试,才能取得较为客观有效的结论。     

Calibrating the Shelf-life of Chinese Flavored Dry Tofu by FTIR Spectroscopy and Chemometrics: Effects of Data Preprocessing and Nonlinear Transformation on Multivariate Calibration Accuracy

This paper demonstrates the application of FTIR spectroscopy coupled with chemometric methods to rapid analysis of the shelf-life of a traditional Chinese food, flavored dry bean curd (tofu). Transmittance FTIR spectra ranging from 4,000 to 400?cm^?1 of 151 dry tofu samples were measured. Sample preparation involved finely grinding of samples and formation of thin KBr disks (under 10?MPa for 5?min). The shelf-life of dry tofu samples by spectroscopic analysis ranged from 29 to 161?days. Two different strategies were investigated to tackle the nonlinear problem: least squares support vector machines and partial least squares (PLS) with nonlinear transformation of spectral data by (a) B-spline function and (b) Gaussian kernel function. Different options of data preprocessing and calibration models were investigated to develop a nonlinear model with good generalization performance. Compared with linear models, both the two proposed strategies can improve the modeling and prediction accuracy with standard normal variate and second-order derivative spectra. B-spline-transformation PLS with second-order derivative spectra obtained a root mean squared error of prediction value of 9.6?days and was recommended as a simple-to-use nonlinear method for shelf-life prediction.     

Varietal Classification of Young Red Wines in Terms of Chemical and Colour Parameters

Six varietal red wines produced in Murcia (Spain) were analysed for selected enological and colour parameters (31 variables in total). As regards acid content there were no important differences among the vinifications studied. The initial content of glucose and fructose was quite high in all the wines, which resulted in very high ethanol content (between 14·1% in Cinsault Noir wine and 16·4% in Tempranillo wine). The colour of the wines was determined by means of the Yxy coordinates and CIELAB parameters, but not one of them could significantly differentiate among vinifications. Principal component analysis and discriminant analysis were used to identify and to explain differences among samples. Discriminant analysis allowed a clear separation of the 80·7% of the cases analysed by a selection of only three variables ( L *, a *, C *). With a selection of 10 variables including x coordinate, colour intensity 1 and 2, pH, ionised anthocyanins, total phenolics, percentage of yellow pigments, total anthocyanins, hue and L * was possible to characterise the 95% of the cases analysed, but 100% in Monastrell-1, Tempranillo Graciano and Cinsault Noir wines.     

Comparison of Different Extraction Methods to Determine Phenolic Compounds in Virgin Olive Oil

A comparison between different extraction methods has been performed in order to assess their effectiveness for the analysis of total phenols (liquid–liquid extraction (LLE), liquid–liquid micro extraction (LLME), and ultrasound liquid–liquid extraction (USE)) and individual phenols (LLME, USE, and solid-phase extraction (SPE)) from virgin olive oil (VOO). Statistical analysis of the analytical data obtained for the total phenol content of a VOO, showed that LLME and USE can represent a reliable alternative to the traditional procedure based on LLE that needs more amount of sample, generates more wastes, and is more time consuming. When an olive oil spiked with phenols was used to test the efficiency of LLME, USE, and SPE methods, the statistical analysis of the data obtained for each individual phenol, again proved LLME and USE methods to be the most suitable, in terms of precision and recoveries, for this purpose. The analysis of real samples (Arbequina and Picual cultivars) confirmed the results obtained for the spiked oil.     

Chlorogenic Acid and Other Phenolic Compounds in Fourteen Sweet Potato Cultivars

Fourteen cultivars of sweet potatoes were analyzed qualitatively for their phenolic content at harvest and after storage. The phenolic content of the sweet potato cultivars, Centennial, Jasper, Jewel, LO-323, L3-243, L3-151, L4-62, L4-112, L4-131, NC-702, NC-718, NC-719, NC-345, and V₂-237, was assayed. The qualitative examination of the sweet potato phenolics resulted in the separation and identification of four isomers of caffeolyquinic acid. A fifth compound, which exhibited phenolic acid characteristics, was separated but could not be identified.     

Composition and Radical Scavenging Capacity of Phenolic Compounds in Wheat-Chickpea Dough

The content, composition, and radical scavenging capacity of phenolic compounds in wheat-chickpea (60:40, w/w) flour and dough were studied in this research. The content of phenolic compounds in wheat-chickpea dough was almost twice as high as in the flour from which the dough was made. The addition of chickpea flour to wheat flour contributed to the improved scavenging capacity of dough. The wheat-chickpea dough had a lower maximal achieved scavenging capacity than wheat-chickpea flour, but higher than that of the wheat dough. The quercetin, genkwanin, and apigenin glucosides could be considered as stable components during the mixing of the wheat-chickpea dough. The wheat-chickpea bread retained the radical scavenging capacity which the dough had.     

Lactic Acid Bacteria in Spanish Red Rose and White Musts and Wines under Cellar Conditions

The dynamics of the lactic acid bacterial (LAB) population in different cellars, fermentation conditions and musts were analyzed. The number of LAB in fresh musts diminished quickly in the first few days, but an increase of these bacteria occurred during the later stages of the alcoholic fermentation. The species found in fresh musts were Lactobacillus plantarum, L. hilgardii, L. brevis, L. confusus, and Leuc. onostoc paramesenteroides. At the end of fermentation only L. hilgardii, Leuc. oenos and L. fructivorans were isolated. The API 50 CHL system was not useful to identify strains of Leuc. oenos species. All the isolated strains degraded malic acid in synthetic medium but only two strains belonging to Leuconostoc oenos species did it in wine.