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1.
As the cultivars of rice markedly affect eating quality, processing suitability, and price, identification or differentiation of rice cultivar is very important. We developed suitable 14 STS (sequence-tagged site) primers for PCR (polymerase chain reaction), and it became possible to differentiate 60 Japanese dominant rice cultivars from each other using template DNA extracted and purified from rice grains. A multiplex primer set was shown to be useful to effectively differentiate rice cultivars produced in various countries by PCR. A novel multiplex primer set for PCR has been developed to differentiate KoshihikariBL, which is closely related with the premium cultivar, Koshihikari, in Japan. The application of the cultivar identification method by PCR method to commercially processed rice products was investigated. We developed an enzyme treatment method, in which the gelatinized starch is decomposed by the heat-stable alpha-amylase at 80 degrees C, followed by the hydrolysis of proteins by proteinase K with sodium dodecyl sulfate and purification of extracted DNAs by phenol/chloroform/iso-amyl alcohol. It became possible to identify the material rice cultivars of the commercially processed rice products, such as cooked rice, rice cake, or rice cracker, by a PCR method using template DNA prepared by the enzyme treatment method and novel multiplex primer sets.  相似文献   

2.
Lower antioxidant activity in white wines in comparison to red wines lies in the low grape-skin-derived polyphenol content. This paper reports the analysis of the antioxidant capacities of white wine samples obtained along two different processing procedures directed to enrich the wine with polyphenols. White wine samples derived from whole squeezed grapes stored for increasing periods of time (up to 18 h) contained increasing concentrations of polyphenols (from 0.35 to 0.55 mmol/L) and, in parallel, exhibited increased capacity to scavenge free radicals and to inhibit copper ion-induced low-density lipoprotein (LDL) oxidation. However, addition of increasing concentrations of alcohol (up to 18%) to the whole squeezed grapes remarkably augmented the extraction of grape skin polyphenols into the wine up to 1.25 mmol/L, resulting in an increased capacity of the wine to scavenge free radicals and to inhibit LDL oxidation, to an extent similar to that of red wine. The extent of LDL oxidation inhibition was directly related to the wine polyphenolic content (r = 0.986). It is concluded that processing white wine by imposing a short period of grape skin contact in the presence of alcohol leads to extraction of grape skin polyphenols and produces polyphenol-rich white wine with antioxidant characteristics similar to those of red wine.  相似文献   

3.
Various treatments, including flash release and addition of pectic enzymes, have been proposed to enhance degradation of grape berry cell walls and extraction of aroma and phenolic compounds into the wines. The effect of flash release and enzyme treatment used separately or in combination on wine polysaccharide composition was studied. The flash release process increased extraction of polysaccharides originating from grape berry cell walls, that is, polysaccharides rich in arabinose and galactose (PRAGs) and type II rhamnogalacturonan (RG-II), thus yielding enriched wines. Increasing the duration of high-temperature exposure before the flash release treatment further increased extraction of polysaccharides. However, the wine obtained by pressing immediately after flash release and fermenting in the liquid phase contained lower amounts of grape polysaccharides, indicating that their extraction required skin maceration. The use of enzymes without or with flash release modified the composition and the structure of pectic polysaccharides. In particular, it induced the loss of PRAG terminal arabinose residues.  相似文献   

4.
In an attempt to develop a technique for the identification of grape cultivars in commercial wines, a method for the extraction of DNA from must and experimental wines was adapted and optimal PCR conditions for the amplification of this DNA were established. DNA was analyzed during the fermentation process for six cultivars (Chardonnay, Clairette blanche, Grenache noir, Merlot, Muscat blanc à petits grains, and Syrah). The extractions were performed on solid parts in suspension as well as on the aqueous fraction. Expected profiles for these cultivars were obtained with DNA extracted from the solid parts during all of the fermentation process and for the wine. The analysis of DNA extracted from aqueous fractions was less reproducible, and microsatellite amplifications were obtained only in the case of Clairette blanche, Merlot, and Syrah wines. Results demonstrate that the purification process is adequate for the analysis but that the DNA concentration represents the main limiting factor. Technical improvements of the method are discussed.  相似文献   

5.
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6.
Sensitive and accurate testing for trace amounts of biotechnology-derived DNA from plant material requires pure, high-quality genomic DNA as template for subsequent amplification using the polymerase chain reaction (PCR). Six methodologies were evaluated for extracting DNA from ground corn kernels spiked with 0.1% (m/m) CBH351 (StarLink) corn. DNA preparations were evaluated for purity and fragment size. Extraction efficiency was determined. The alcohol dehydrogenase gene (adh1) and the CBH351 (cry9C, 35S promoter) genes in the genomic DNA were detected using PCR. DNA isolated by two of the methods proved unsuitable for performing PCR amplification. All other methods produced some DNA preparations that gave false negative PCR results. We observed that cornstarch, a primary component of corn kernels, was not an inhibitor of PCR, while acidic polysaccharides were. Our data suggest that amplification of an endogenous positive control gene, as an indicator for the absence of PCR inhibitors, is not always valid. This study points out aspects of DNA isolation that need to be considered when choosing a method for a particular plant/tissue type.  相似文献   

7.
不同品种红葡萄酒花色苷高效液相色谱指纹图谱识别   总被引：9，自引：0，他引：9  
利用高效液相色谱法建立了9个品种葡萄酒的花色苷指纹图谱，对不同品种葡萄酒进行识别。HPLC检测：采用反相C18柱，调整流动相pH值1.6，二元梯度洗脱，检测波长518 nm。指纹图谱建立方法：计算HPLC色谱峰的相对保留时间和相对峰面积，按相对保留时间排列相对应的相对峰面积。采用夹角余弦法计算相关系数，并使用SPSS11.0统计分析软件对指纹图谱进行系统聚类分析。结果表明：不同品种葡萄酒花色苷的HPLC指纹图谱存在着差异，山葡萄种及杂种葡萄酒具有区别于欧亚种葡萄酒的特征色谱峰；不同品种葡萄酒花色苷指纹图谱的相似性不同，不同种间品种葡萄酒相似性较差；系统聚类分析初步建立了不同品种葡萄酒花色苷识别模式，对葡萄酒进行了较好的识别。指纹图谱技术结合聚类分析是识别不同酿造品种葡萄酒的有效方法之一。  相似文献   

8.
The flash release (FR) process, consisting of rapidly heating the grapes and then applying strong vacuum, has been proposed to increase the polyphenol content of red wines. Its impact on polyphenol extraction kinetics and on the polyphenol composition of red juice and wines was studied over two seasons on different grape varieties (Grenache, Mourvedre, Carignan). The FR process allows fast extraction of all phenolic compounds (hydroxycinnamic acids, flavonols, anthocyanins, catechins, proanthocyanidins) and can be used to produce polyphenol-enriched grape juices. However, the concentration of all polyphenols dramatically decreased throughout fermentation when pressing was achieved immediately after FR. The FR wines made with pomace maceration were also enriched in polyphenols compared to the corresponding control wines. Increasing the duration of high-temperature exposure in the FR treatment further increased extraction of phenolic compounds but also accelerated their conversion to derived species. The tannin-to-anthocyanin ratio was particularly low in the wine fermented in the liquid phase, higher after FR than in the control, and even higher after longer heating. FR resulted in an increased tannin-to-anthocyanin ratio and an increased conversion of anthocyanins to tannin-anthocyanin adducts showing the same color properties as anthocyanins. The tannin-to-anthocyanin ratio was particularly low in the wine fermented in the liquid phase that also contained larger amounts of orange sulfite bleaching-resistant pigments.  相似文献   

9.
A rapid and comprehensive qualitative method has been developed to characterize the different classes of polyphenols, such as anthocyanins, flavonols, phenolic acids, and flavanols/proanthocyanidins, in grape products. The detection was achieved by two runs with the same LC gradient in different MS ionization modes and mobile phase modifiers (positive ionization mode and 0.4% trifluoroacetic acid for anthocyanins and flavonols; negative ionization mode and 0.1% formic acid for phenolic acids and flavanols). From an analysis of the MS and UV data and in comparison with the authenticated standards, a total of 53 compounds were identified, including 33 anthocyanins, 12 flavonols, 4 phenolic acids, and 4 flavanols/proanthocyanidins. With the method developed, a survey was then conducted to qualitatively assess the composition of polyphenols among 29 different grape products including original grape, grape juice, grape wine, and grape-derived dietary supplements, and their chemical profiles were systematically compared. This method provided a comprehensive qualitative insight into the composition of polyphenols in grape-derived products.  相似文献   

10.
Pure supercritical CO(2) was used to remove >95% of the oil from the grape seeds. Subcritical CO(2) modified with methanol was used for the extraction of monomeric polyphenols, whereas pure methanol was used for the extraction of polyphenolic dimers/trimers and procyanidins from grape seed. At optimum conditions, 40% methanol-modified CO(2) removed >79% of catechin and epicatechin from the grape seed. This extract was light yellow in color, and no higher molecular weight procyanidins were detected. Extraction of the same sample after removal of the oils and polyphenols, but now under enhanced solvent extraction conditions using methanol as a solvent, provided a dark red solution shown via electrospray ionization HPLC-MS to contain a relatively high concentration of procyanidins. The uniqueness of the study is attested to by the use of CO(2)-based fluids and the employment of a single instrumental extraction system.  相似文献   

11.
菜籽蛋白加工废液中多酚和多糖同步提取工艺优化   总被引：6，自引：4，他引：2  
为开发利用菜籽蛋白加工废液中的生理活性物质,该研究在单因素试验基础上,采用Box-Behnken响应面试验设计法,对菜籽蛋白加工废液中多酚和多糖提取工艺条件进行优化,同时探究两种物质的体外抗氧化活性。结果表明,影响菜籽蛋白加工废液中多酚和多糖得率的因素大小顺序为:乙醇体积分数浸提温度浸提时间,最佳提取工艺为:浸提温度60℃、乙醇体积分数65%、浸提时间31 min,在此条件下多酚得率为2.19%,多糖得率为8.14%;多酚提取物对DPPH·具有较强清除能力,其半抑制质量浓度为0.20 mg/mL,多糖提取物对DPPH·和·OH均具有较强的清除能力,其半抑制质量浓度分别为1.45、2.38 mg/mL;高效液相色谱法初步检测表明,菜籽蛋白加工废液中含有香豆酸、丁香酸、对香豆酸、芥子酸和苯甲酸。研究结果为菜籽蛋白加工废液的再利用提供参考。  相似文献   

12.
Knowledge about the relation between grape and wine phenolics is of key interest for the wine industry with respect to being able to predict wine quality from analyses of grapes. Prediction of the phenolic composition and color of experimentally produced red wines from the detailed phenolic composition of the corresponding grapes was investigated using a multivariate approach. Grape extracts and wines were produced from 55 different grape samples, covering 8 different Vitis vinifera cultivars: Alicante, Merlot, Syrah, Cinsault, Grenache, Carignan, Cabernet Sauvignon, and Mourvedre. The phenolic composition of the grapes and wines showed that the average ratios between wine and grape phenolics ranged from 0.25 to 7.9 for the different phenolic compounds. Most interestingly, the average ratios were low for anthocyanins (0.31) and tannins (0.32), intermediate for (+)-catechin (0.75) and polymeric pigments (0.98), and high for gallic acid (7.9). Individual wine phenolics in general correlated well with several grape phenolics, indicating that a multivariate approach might be advantageous for prediction of wine phenolics from grape phenolics analysis. However the use of multivariate prediction of individual wine phenolics from the complete grape phenolic composition only improved the prediction of wine polymeric pigments, whereas wine anthocyanins were predicted with the same precision as from the direct relation with grape anthocyanins. Prediction of color attributes of pH normalized experimental wines from the phenolic profiles of grapes was accomplished using a multivariate approach. The correlation between predicted and measured total wine color was high ( r = 0.958) but was very similar to the correlation coefficient obtained for the direct relation between grape anthocyanins and total wine color ( r = 0.961). Color due to copigmentation, color due to anthocyanins, and color intensity were also predicted well.  相似文献   

13.
Grape pomace contains appreciable amounts of polyphenolic compounds such as anthocyanins and procyanidins which can be recovered for use as food supplements. The extraction of these polyphenols from the pomace is usually accomplished at slightly elevated temperatures, frequently employing hydroethanolic solvents. Due to governmental regulations and the cost involved in using ethanol as a solvent, as well as the loss in polyphenolics due to thermal degradation, improved extraction techniques are required. In this study, a semicontinuous extraction apparatus employing only water was developed to maximize the recovery of anthocyanins and procyanidins from red grape pomace (Vitis vinifera). Water is preheated prior to its entry to the extraction cell containing the grape pomace sample, where it is allowed to then flow continuously through the unheated extraction vessel prior to its collection at ambient conditions. Extraction variables that impacted the polyphenolic recovery included pomace moisture content (crude or dried), sample mass, water flow rate, and extraction temperature. A response surface method was used to analyze the results from the extraction, and the optimal conditions were found to be 140 °C and 9 mL/min water flow rate. These conditions can produce an extract containing 130 mg/100 g DW of anthocyanins and 2077 mg/100 g DW of procyanidins. Higher yields of polyphenolics were observed using crude (wet) rather than dried pomace, hence avoiding the need to dry the pomace prior to extraction. The described semicontinuous extraction method using only water as the extraction solvent under subcritical conditions allowed the efficient extraction of polyphenols from red grape pomace without the attendant loss of polyphenolic content due to having to heat the extraction vessel prior to commencement of extraction.  相似文献   

14.
Passing from must to wine produced a loss of low-molecular-weight grape structural glucosyl polysaccharides, and an important gain in yeast mannoproteins (MP) and grape-derived arabinogalactan proteins (AGP), and rhamnogalacturonans-II (RG-II). AGP were more easily extracted than RG-II, and small quantities of RG-II monomers and galacturonans were detected. Postmaceration produced a reduction in all grape polysaccharide families, particularly acute in AGP. The reduction of polysaccharides during malolactic fermentation only affected grape AGP, and MP were continuously liberated during the entire vinification process. Wine oak and bottle aging was associated with a relative stability of the polysaccharide families. AGP were thus the majority polysaccharides in young wines but, contrary to what may be thought, structural glucosyl oligosaccharides dominated in musts and MP in aged wines. Precipitation of polysaccharides was noticeable during vinification, and it mainly affected high-molecular-weight AGP and MP. Hydrolytic phenomena affected the balance of wine polysaccharides during late maceration-fermentation.  相似文献   

15.
Background, aim and scope  An improving knowledge of bacterial community within natural environments including forest soils and leaf litters requires extraction of nucleic acids directly from environmental samples since molecular approaches provide less biased access to a larger portion of uncultivable microorganisms. However, when DNA was extracted successfully from these samples, it might still have been difficult to apply it as a template for polymerase chain reaction (PCR) amplifications due to the effect of PCR inhibitors. Various compounds from plant tissues including polysaccharides, phenolic compounds and especially humic acids can inhibit PCR amplification. Some of these inhibitors could inhibit PCR amplification by chelating the Mg2+ (cofactor for Taq polymerase), or by binding to target DNA, and PCR amplification would consequently be interfered with. Therefore, eliminating the effects of these PCR inhibitors is one of the most important steps for PCR-based molecular techniques. Four different methods were assessed in this study to purify the genomic DNA extracted from F, L layer leaf litters and forest soil in an exotic pine plantation of southeast Queensland, Australia. Materials and methods  Three samples including two leaf litters and one forest soil were collected with a core (25 × 40 cm) from a 22-year-old slash pine plantation in southeast Queensland, Australia. The DNA fragments were extracted directly using the Ultra Clean™ Mega Prep Soil DNA kit (Mo Bio Labs, Solana Beach, CA). Then, four different purification methods were applied and compared to purify the DNA for PCR amplification, which include PVPP, Sephadex TM spin column, low-melting agarose gel and a new modified gel purification method. The purified DNA from these four purification methods was detected by agarose gel electrophoresis, and the purity and usefulness of DNA samples were ultimately determined by successful PCR amplifications. Results and discussion  The DNA was extracted from each sample using the Ultra Clean™ Mega Prep Soil DNA kit, and the DNA eluents were dark in colour and sometimes formed compact aggregates. Subsequently, PCR amplification from such samples failed, although a series of dilutions had been made from neat to 1:103. The DNA purification step could not, therefore, be avoided. It was observed that both the colour of eluent and the DNA concentration decreased gradually after elution. Considering the difficulties of removing PCR inhibitors and the possibility of high DNA losses, 50–200 μl of sample DNA was used for purification. Four DNA purification methods (the PVPP spin column, Sephadex™ spin column, low-melting agarose gel and the modified gel purification method) were applied and compared on leaf litter and soil samples. The DNA purified by the modified gel purification method provided the best PCR products for 16S rRNA gene amplification, but the other methods, PVPP, Sephadex™ spin column and low-melting agarose gel, produced very weak or no products. Thus, in this study, DNA fragments which were purified by the modified gel purification method were amplified efficiently. This may be attributed to running the low-melting agrose gel for a longer time, which could remove substantial humic substances and also some other compounds from the samples and, thus, prevent them from being involved in PCR amplification. Conclusions  A new modified gel purification method which can improve DNA purification and PCR amplification of environmental DNA is first introduced in this study. Comparing PVPP, Sephadex ™ spin column, low-melting agarose gel and modified gel purification method for the effect of DNA purification, the modified gel purification method is more successful in removing the PCR amplification inhibitors and obtaining the highly purified PCR amplifiable high-molecular-weight DNA. The method described here is cheap, fast and easy to operate. It suggests in this study that the method containing less and easier following steps should be widely used to relieve the heavy working load of molecular-biological researchers. Recommendations and perspectives  This study introduces a new modified DNA purification method, and it is found that this modified gel purification method is effective in removing the PCR inhibitors and obtains highly purified DNA from leaf litters for PCR amplification. The modified gel purification method may have wider applications, although it was only assessed on leaf litter and soil samples. The effect of the modified gel purification method on the DNA purification would need to be further investigated on a variety of samples which suffered from PCR inhibitors, such as clinical samples, plant tissues and environmental samples.  相似文献   

16.
DNA isolation from plants is sometimes difficult due to the existence of high levels of endogenous phenolics, polysaccharides, or other substances that may interfere with DNA extraction. Theobroma cacao produces high levels of anthocyanins in young leaves. These plant polyphenols can interfere with DNA isolation. After examination of various procedures for DNA isolation, two commercial isolation procedures have proved to be repeatedly successful using these types of plants, the D(2) BioTechnologies DNA X-tract Plus kit and the Qiagen DNeasy Plant System DNA kit. These commercial kits were chosen for their speed and ease over the CTAB procedure, which is more labor intensive. All protocols assessed yielded DNA suitable for AFLP or SSR procedures. An additional factor in DNA extraction efficiency is the degree of cell breakage, which may be more difficult with the highly fibrous leaf tissue that is found in many monocots, including date palm. Two commercially produced pieces of equipment were tested and, for cacao, both resulted in template DNA yielding amplification product in AFLP or SSR fingerprinting. However, for the fibrous date palm leaf, the larger FastPrep homogenizer consistently yielded DNA that generated higher signals when amplified than did the smaller Disruptor Genie.  相似文献   

17.
The aim of this study was to determine the impact of two different treatments of early defoliation performed before blooming on: grape yield, chemical parameters, polyphenols content, and antioxidant activity of grape and red wine cv. Cabernet Sauvignon from the vineyard located in Ilok, the eastern continental region of Croatia. Two different treatments of leaf removal (LR) were performed: removal of 3 leafs (T1) and 6 leafs (T2) before blooming, together with control (no leaf removal) (T3) during two years (2013 and 2014). Crop yield and average cluster weights per vine were determined. Density, pH and titratable acidity were measured in must, while the total phenols, total anthocyanins and antioxidant activity were measured in the extract of grape skin and produced wine. The analysis of individual anthocyanins in wine was performed by HPLC method. T2 treatment significantly lowered the crop yield and the average cluster weights, and increased total phenols, total anthocyanins, antioxidant activity and most abundant individual anthocyanins in wine. Defoliation did not affect the other chemical parameters in must, grape skin extract and wine. Vintage year is statistically the most significant source of variability for density of must, antioxidant activity in grape skin extract, as well as pH and titratable acidity in wine. This study has showed that the early leaf removal treatment in eastern continental part of Croatia could be used for the production of smaller quantity of high quality Cabernet Sauvignon red wine abundant with anthocyanins.  相似文献   

18.
The effect of addition of grape seed tannins on the phenolic composition, chromatic characteristics, and antioxidant activity of red wine was studied. Two highly pure commercial grape seed tannins (GSE100 and GSE300) were selected, and their phenolic compositions were determined. Two types of red wines were made with Castela?o/Tinta Miu?da (3/2, w/w) grapevine varieties by fermentation on skin using two different maceration times, which correspond to the wines rich and poor in polyphenols, respectively. Each of these wines was used for experimentation with the addition of GSE100 and GSE300 before and immediately after alcoholic fermentation. Phenolic composition, chromatic characteristics, and antioxidant activity of the finished red wines were analyzed by HPLC-DAD, CIElab 76 convention, and DPPH radical test, respectively. The results showed that the addition of grape seed tannins had obvious effects of increasing color intensity and antioxidant activity only in the wines poor in polyphenols. Although GSE300 contained much higher amounts of di- and trimer procyanidins and a lower amount of polymeric proanthocyanidins, it provided effects of increasing the color intensity and antioxidant activity of the wines poor in polyphenols similar to those of GSE100. Furthermore, GSE100 released more gallic acid to wines than GSE300, although no gallic acid was detected in GSE100. Tannins added after alcoholic fermentation had a better effect on phenolic composition of red wine than tannins added before alcoholic fermentation.  相似文献   

19.
A simple method for the analysis of major wine volatiles and semivolatiles by stir bar sorptive extraction in combination with thermal desorption and gas chromatography-mass spectrometry (SBSE-TD-GC-MS) was developed. Significant experimental parameters such as extraction time, temperature, salt addition, pH, and thermal desorption parameters were optimized to provide a sensitive and robust analytical method. The method provided good repeatability (%RSD < 10%) for 38 major wine volatile compounds, including alcohols, acids, esters, phenols, aldehydes, ketones, and lactones. Quantitative data for 62 South African red and white wines were used to study the suitability of major volatile data for the differentiation of wine samples according to grape variety or cultivar. Principal component analysis (PCA) and cluster analysis (CA) showed that most of the variation in volatile composition between wine samples could be ascribed to differences in wine age, wood contact, and fermentation practices. Despite the contribution of these factors, discriminant analysis (DA) was successfully applied to the classification of red and white wine samples according to cultivar.  相似文献   

20.
Antioxidant thio-conjugates were obtained from white grape pomace by a clean and efficient one pot extraction and depolymerization method using water and cysteamine hydrochloride. To evaluate the potential of grape pomaces of different origins as sources of proanthocyanidins and conjugates, we conducted varietal comparative studies of polyphenol content, antioxidant power, and procyanidin composition. Xarel.lo proved to be the richest source of polyphenols. The total conversion into the conjugates was as high as 8 g/kg of Xarel.lo grape pomace, with a 50-fold excess of cysteamine, and 3 g/kg, with a 5-fold excess of cysteamine. After purification by preparative cation exchange and reversed phase high-performance liquid chromatography, 17 g of 63% pure 4beta-(2-aminoethylthio)epicatechin (acetate salt) was obtained from 35 kg of moist pomace. The procedure described here will make the antioxidant thio-derivatives efficiently available directly from raw plant byproducts such as grape pomace.  相似文献   

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