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1.
研究琐琐葡萄果实总黄酮的醇法提取工艺。在考察各影响因素的基础上设计正交试验,得出各种因素对提取效果影响的主次顺序为料液比>提取时间>提取温度>乙醇体积分数,总黄酮提取最佳工艺条件为:提取温度80℃、乙醇体积分数60%、提取时间120min、料液比1:30(g/mL)。  相似文献   

2.
先用95%乙醇浸泡,然后用乙酸乙酯和正丁醇从琐琐葡萄中提取其活性成分,并探讨了其抑菌作用。结果表明,琐琐葡萄乙酸乙酯和正丁醇提取物对微生物有明显抑制作用。  相似文献   

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The amino acid composition, physicochemical and functional properties of grape (Vitis vinifera L.) seeds protein (GSP) were evaluated and compared with those of soybean protein isolate (SPI). Amino acid analyses of GSP revealed high levels of glutamic/glutamine, glycine and aspartic/asparagines. SDS‐PAGE analysis demonstrated that globulin was the major protein component in GSP, whose subunit molecular weights were mainly varied from 25.5 to 40.0 kDa. The isoelectric pH of GSP was found to be at the acidic pH of around 3.8. At all the pHs tested except pH 2.0, no significant changes of GSP secondary structure were observed. GSP exhibited beneficial functional properties such as preferable solubility and emulsifying activity, while the foaming properties and water holding capacity were relatively poor compared to SPI. It could then be employed to soup, sauce, beverage or meat product for improving nutritional and sensory quality of these foods at appropriate pHs.  相似文献   

4.
自动质谱图解卷积和鉴定系统(AMDIS)是美国标准化委员会推出的一款辅助气质数据定性分析的软件,利用该软件可有效的克服GC-MS定性分析中基质效应和共洗脱效应的干扰,增加解谱的准确性和可靠性.本研究将GC-MS检测技术和AMDIS辅助解谱相结合,从雷司令葡萄果实中鉴定出15种降异戊二烯类物质,他们多数以游离态形式存在,在果实发育早期或转色前期含量最高;此外还检测到4种结合态该类化合物.在成熟果实中,β-大马士酮和β -紫罗兰酮含量远高于其感觉阈值,呈现煤油味的TDN也略高于其阈值.该研究为AMDIS技术在果实香气成分分析中的推广应用提供了参考.  相似文献   

5.
以葡萄总RNA为模板,利用RT-PCR的方法从葡萄中扩增获得一条白藜芦醇合酶基因完整的c DNA序列,命名为RS。利用生物信息学软件对其核酸和蛋白质序列进行分析,结果表明,该序列长1179 bp,与已报道的葡萄白藜芦醇合酶基因的序列相似性达到94%99%,氨基酸序列相似性为96%99%;RS基因编码392个氨基酸,氨基酸序列含有完整的芪合酶家族的特征序列GVLFGPGLT和活性中心序列GCYAGGTVLR;预测的分子量为42.78 k Da,理论等电点为6.57,不稳定参数为35.92,在分类上属于稳定性蛋白;二级结构主要以α-螺旋、无规则卷曲以及β-折叠为主,其中α-螺旋含量为44.13%、无规则卷曲含量为26.53%,β-折叠含量为17.66%。   相似文献   

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Two watering and two nutrient regimes were applied to small vines established in pots and grown under greenhouse conditions. With water, a comparison was made between water adequacy (WH) and intermittent water stress (WL); with nutrition, between nutrient sufficiency (NH) using fertiliser-enhanced potting medium and insufficiency (NL) with one-fifth fertiliser application. NL reduced major growth parameters - shoot length, stem weight and leaf weight - more than did WL. Both NL and WL reduced node and leaf number, but only NL reduced internode length, leaf area and weight. WL had bigger effects when combined with NH than with NL. WL, especially when combined with NH, advanced maturity by ten days. Effects of W and N on pH, malic acid, tartaric acid and total soluble solids (°Brix) were different. The °Brix values were similar in WH and WL, but were less in NH than in NL. The treatments interacted in pH, malate and tartrate: pH was highest in WL/NH and lowest in WH/NH; malate tended to be less at both WL and NL, while tartrate concentration tended to become smaller from WH to WN but greater from NL to NH. No significant changes in the levels of citric acid, anthocyanin or reducing sugars were observed as a consequence of any treatment. Thus, although levels of stress due to WL or NL may have been different, the differences in the effects on several variables indicate that there is no general response to stress but that responses vary according to the factor inducing the stress. The level of reduction in variables measuring vegetative growth was 2– to 3-fold greater than induced changes in juice composition. Advancement of maturity would suggest a potential value of intermittent water stress combined with adequate nutrition in areas with short seasons. Low-nutrient soils might be desirable in areas where other factors are likely to induce strong growth.  相似文献   

8.
This study lays bare two main objectives. The first is to determine the amount of anthocyanins in the leaves of Vitis vinifera L. by the spectrophotometric method and the second is to dye cationized and non-cationized cotton fabrics with the V. vinifera L. leaves aqueous extract. We have thoroughly investigated the effects of dye bath pH and temperature on the dyeing proprieties of the aforementioned fabrics. The color strength (K/S value) of dyed cationized cotton fabrics (K/S = 12) has been better than the non-cationized ones (K/S = 4). Experimental results show that the fastness properties of dyed cationized cotton fabrics range from average to good. We find that the cationization of cotton fabrics has largely improved the dyeability and fastness properties of cotton fabrics dyed with V. vinifera L. leaves aqueous extract.  相似文献   

9.
以苹果木烟熏液为研究对象,从感官品质、pH值、羰基化合物、酚类化合物、苯并(a)芘的含量、挥发性风味物质的组成和电子鼻分析等角度研究苹果木烟熏液的性质,并与目前市场上烟熏液产品进行比较。结果表明,苹果木烟熏液pH值为2.31,酚类化合物、羰基类化合物的含量分别达到9.94 mg/mL和7.91 g/100 mL,挥发性风味物质以酚类物质和醛类为主,相对含量分别为36.15%和17.58%,通过电子鼻主成分分析发现,苹果木烟熏液与其他几种烟熏液之间主成分有显著性差异,与市场其他烟熏液相比,在核心成分和特征性风味物质均有明显的优势,同时无苯并(a)芘检出,表明苹果木烟熏液具有良好的应用前景。  相似文献   

10.
Background and Aims:  Little work has been conducted on the effects that summer pruning operations have on the relative growth of grapevine berry parts. Our paper studies whether pre-bloom leaf removal is able to modify the proportions of seed, skin and flesh in ripe grapevines berries and the related effects on must composition.
Methods and Results:  Pre-bloom defoliation (D) of the first six basal leaves on main shoots was applied to the field-grown cvs Barbera and Lambrusco salamino ( Vitis vinifera L.) in Italy's Po Valley and compared with non-defoliated controls. D showed reduced fruitset, hence yield per shoot, and concurrently improved must soluble solids and total anthocyanins in both cultivars as a likely result of increased leaf-to-fruit ratio (+3.4 cm2/g and +5.2 cm2/g for Barbera and Lambrusco, respectively) and improved relative skin mass (from 6.0 to 9.0% in Barbera and from 8.1 to 10.4% in Lambrusco). In both cultivars, skin and seed mass were highly correlated with total berry mass and changes in relative skin mass were generally not related to berry size.
Conclusions:  These results indicate that berry size per se is not the primary factor in determining final grape composition, which instead seems to depend upon factors differentially affecting the growth of the various berry components.
Significance of the Study:  Pre-bloom D induced a consistent, site and cultivar-independent increase in relative skin mass suggesting this effect being strongly physiologically regulated.  相似文献   

11.
Greco grape (Vitis vinifera L.), a typical white variety of Campania region in the South of Italy, was investigated for the first time determining volatile‐free and glycosidically bound secondary metabolites that could be at the base of the aroma profile of DOCG ‘Greco di Tufo’ wines. C18 reversed‐phase isolates of ‘Greco’ musts have been investigated by gas chromatography/mass spectrometry. ‘Greco’ must resulted characterised by a content of glycoconjugated terpenoids ranging from 180 to 370 μg L?1. Linalool and geraniol detected in the ‘Greco’ must above their odour thresholds could explain a floral character attributed to the wine. Guaiacol in free fraction, 4‐vinylguaiacol and eugenol in the bound fraction could be at the origin of nutty and spicy notes of the wine. Some observations of this study also show that precursors of floral, spicy and nutty odorants seem to be enhanced by clay soil and good sun exposure.  相似文献   

12.
Background and Aims: Cost-effective yield control is required by the wine industry in order to reduce the existing worldwide wine surplus and to improve grape quality. The object of this study was to evaluate the chemical and sensory effects on the resulting wines of mechanical cluster thinning performed at different intensities on Grenache, and at different timings (pea size and veraison) on Tempranillo. Methods and Results: The experiments were conducted with a machine harvester in 2007 on two commercial vertical shoot-positioned vineyards in Spain's Rioja region. In both varieties, mechanical thinning was effective in yield reduction and resulted in more ripened fruit, and wines with higher alcohol and pH values, more intense colour and increased phenolic content. Regardless of the thinning intensity, sensory changes were less noticeable in Grenache than in Tempranillo wines. Of the latter, those from vines thinned during veraison were less aromatic and sour, but had increased astringency. Conclusions: Yield management through mechanical thinning induced changes to the chemical composition of fruit and wines as well as to the wines' aroma, taste and mouthfeel. The extent of the sensory implications seems to depend on several factors such as the variety and timing of thinning application. Significance of the Study: This is one of the first studies addressing the effects of mechanical thinning on the sensory properties of the resulting wine and has implications for viticultural management practices.  相似文献   

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The genetic diversity of Saccharomyces cerevisiae associated to the must (Vitis vinifera Albariño) from different geographic areas and spontaneous fermentation was studied by analysis of mitochondrial DNA restriction fragment length polymorphism (mtDNA RFLP). Colonies were isolated in musts at different stages of fermentation from three different geographic areas, O Val do Salnés, O Rosal and O Condado do Tea from Galicia (NW Spain). A total of 17 different patterns out of 273 S. cerevisiae colonies were identified using mitochondrial DNA restriction analysis. Pattern I from O Rosal, VI from O Val do Salnés and XII from O Condado do Tea were the predominant ones. Only pattern II was common to all fermentations. This molecular study provides useful information about distribution and genetic relationships among several S. cerevisiae strains associated to Vitis vinifera Albariño from different vineyard ecosystems and their influence on certain oenological properties.  相似文献   

17.
Wine aroma is formed by volatile compounds of different chemical natures and origins. Betanzos is the most northern viticole geographic area from Galicia (NW Spain). The aromatic profiles of wines produced from two white varieties (Blanco lexítimo and Agudelo) and one red variety (Serradelo) from Betanzos, harvested in 2006 and 2007, have been established by gas chromatography (GC/FID). A total of 35 varietal and fermentative aroma compounds were identified and quantified in free volatile form, which include terpenols, C13‐norisoprenoids, alcohols, esters, volatile fatty acids and volatile phenols. To ascertain the compounds with major impact odours, the Odour Activity Value (OAV) was calculated. Twelve compounds showed concentrations above their perception threshold (OAV>1). The results obtained suggest that ethyl octanoate (apple), isoamyl acetate (banana), ethyl hexanoate (fruity) and β‐damascenone (floral) were the most powerful odorants for the white wines Blanco lexítimo and Agudelo from Betanzos. Ethyl octanoate and β‐damascenone (fruity and floral aroma respectively) were the most odorant for the red wine Serradelo.  相似文献   

18.
花芽分化是葡萄产量形成的生理基础。为了解葡萄不同节位芽发育的情况,本试验以6年生藤稔品种为试材,通过在枝条不同节位进行修剪并仅保留顶部2个芽的处理,研究了不同节位芽萌发新梢的开花及结果习性。结果表明,不同节位的修剪处理均不同程度地增加了结果枝的粗度和花序数,果穗和果实性状也有所提高。  相似文献   

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Polyphenols extracted from the seeds of Vitis vinifera L. cv. Shiraz berries were monitored during berry development. Initially seeds were green, plump and had pliable seed coats, but beginning at veraison the seeds browned in colour, became desiccated and the seed coats hardened. Isolated polyphenols consisted of flavan-3-of monomers ((+)-catechin, (-)-epicatechin and (-)-epicatechin-3-O-gallate) and procyanidins. The procyanidins were maximal in the 3 weeks prior to veraison, increasing little during this period. The amounts of flavan-3-ol monomers increased 5-fold during this same period of time, indicating that the procyanidins and the flavan-3-ol monomers accumulate at different stages. Beginning at veraison, amounts of all polyphenols declined and changed in composition. The decrease in amount followed second-order kinetics. Polyphenol changes after veraison could be explained by oxidation and therefore, electron paramagnetic resonance (EPR) spectroscopy was used to follow the potential development of radical species in the developing seeds. Spectra consistent with a phenoxyl radical were observed in the developing seeds. The concentration of radicals remained low until veraison but then increased, reaching a maximum three weeks later, declining slowly thereafter. Changes in radical intensity together with other documented changes in the seed are consistent with an oxidative event occurring during fruit ripening.  相似文献   

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