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1.
In this study, anthocyanins in 17 samples of blueberries of different varieties and geographical origins in China (including Duke, Bluecrop, Northland, Northblue, Spartan, and St. Cloud blueberry varieties) were identified and quantified. Thirteen anthocyanins were identified by means of their absorbance spectrum and fragmentation pattern in tandem mass spectrometry. The anthocyanin profiles from blueberries of all cultivars were similar, but the proportions were cultivar-dependent. Malvidin (41.0%), delphinidin (33.1%), and petunidin (17.3%) were the major contributors to the total anthocyanidin content. The multivariate method of principal component analysis (PCA) was used to evaluate the differences among the cultivars. The results showed that each species could be separated from others cultivated in China, primarily by the proportions of each anthocyanin compound in each blueberry variety. The differences were probably due to the cultivar and climatic factors. 相似文献
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Detecting adulteration in honey is not an easy task and most of the traditional methods are usually unaffordable. Thus, we describe the use of cyclic voltammetry using Cu/CuO electrode and UV–vis spectrophotometry along with chemometric tools to detect adulteration of honey with corn syrup. Both honey and corn syrup samples presented an anodic peak at +1.1 V, but the current is variable and depends on the sample composition in relation to the honey and syrup content. A cathodic peak at +0.42 V arises at higher scan rates, which is more pronounced for syrup samples and can be used to discriminate between pure and adulterated samples. This response can be combined with UV/vis absorbance peaks at 285 and 216 nm to identify adulteration. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) allowed differentiating between honey and corn syrup samples and simulated mixtures of them, in which the first two principal components together explain 100.0 % of the data variability, specifically 98.47 % by PC1 and 1.53 % by PC2. The method requires a minimum amount of sample and generates a low amount of waste. Furthermore, it is possible to use portable and cheap equipment, making it more accessible to the beekeeper sector. 相似文献
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Evaluation of the antioxidant activity of components of the diet is important in order to establish healthy consumption patterns. Data are reported here on the antioxidant activity (FRAP and ABTS), of 20 commercial grape juices and 10 typical Spanish wines and on their content of total phenolic compounds, anthocyanins, flavonoids and 10 individual phenolic compounds (flavanols, benzoic acids and cinnamic acids, measured by HPLC-UV). Red grape juices had a significantly higher (p < 0.05) concentration of total phenols (1177 vs. 744 mg gallic acid/L), flavonoids (98 vs. 63 mg catechin/L) and a higher antioxidant activity (9.16 vs. 2.83 meq Trolox/L) in comparison to white grape juices. In comparison to the white wines, white grape juices contained more total phenols (744 vs. 286 mg gallic acid/L) and flavonoids (63 vs. 29 mg catechin/L) and evidenced higher antioxidant activity (p < 0.05). In comparison to the red wines, a lower content of total phenols (286 vs. 2358 mg gallic acid/L) and flavonoids (228 vs. 29 mg catechin/L) and an absence of anthocyanins were observed in the white wines, which are therefore less antioxidant. Although a two-fold higher concentration of antioxidant compounds was found in red wines than in red grape juices, the latter may be a good option for all age groups because of the absence of alcohol and the potentially beneficial health effects of their phenolic composition and elevated antioxidant activity. 相似文献
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Phenolic compounds in sixteen Cabernet Sauvignon wines from different wine-growing sub-regions in the Balkan region were investigated using HPLC with DAD and fluorescence detector and spectroscopic analysis, as well as statistical PC/F and cluster analysis. The HPLC analysis of investigated red wines showed that the content of total hydroxybenzoic acids, detected at 280 nm, was the highest in wines from Tikveš wine-growing subregion, Macedonia (127–140 mg L−1). Total hydroxycinnamic acids, detected at 320 nm, were the highest in wines from Župa wine-growing subregion, Serbia (43–45 mg L−1). The concentration of total flavonoids (flavan-3-ols, flavonols, flavons and flavanon), detected at 280, 360 and 322/275 nm, respectively, was the highest in wine from Katarzyna Estate wine-growing subregion, Bulgaria (167 mg L−1). Finally, the concentration of total anthocyanins, detected at 520 nm, was the highest in wine from Šumadija wine-growing subregion, Serbia (1463 mg L−1). The results of PCA and cluster analysis together confirmed that the content of phenolic compounds in Cabernet Sauvignon wines depends on agro-climatic factors, oenological practice in different wineries and the growing season in the Balkan region that were investigated. The areas in the Balkan region in this study with similar agro-climatic characteristics showed shorter clustering distance, indicating similar phenol profiling in the red wines tested. 相似文献
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Frederick Khachik 《Journal of food composition and analysis》2011,24(6):826-829
Human plasma and tissues contain in excess of 12 dietary carotenoids and several metabolites that originate from consumption of fruits and vegetables. The major hydroxycarotenoids absorbed by humans are: (3R,3′R,6′R)-lutein (1), (3R,3′R)-zeaxanthin (2), (3R,6′R)-α-cryptoxanthin (3), and (3R)-β-cryptoxanthin (4) and their E/Z-stereoisomers. In addition, several hydroxycarotenoids that result from metabolic transformation of 1 have also been identified in human plasma and ocular tissues. Epidemiological and experimental evidence to date suggest hydroxycarotenoids may protect against chronic diseases such as cancer, cardiovascular disease and age-related macular degeneration (AMD). Therefore, supplementation with these carotenoids in individuals with a low dietary intake of fruits and vegetables is essential. However, with the exception of 1 and 2, industrial production of 3 and 4 have not yet materialized. A relatively straightforward semisynthetic process has been developed that transform 1 into a mixture of 3 (12%) and 4 (80%). Hydroxycarotenoid 3 can also be directly prepared from allylic deoxygenation of 1 in a single step in an excellent yield. These two processes provide an easy access to optically active 3 and 4 that are normally prepared by numerous synthetic steps. 相似文献
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Maria-Ioanna Salaha Stamatina Kallithraka Ioannis Marmaras Elisabeth Koussissi Irini Tzourou 《Journal of food composition and analysis》2008,21(8):660-666
An alternate to sulphur dioxide natural antioxidant was tested during 2005 harvest on four different red vinifications, and was applied in each winemaking batch in combination with sulphur dioxide and on its own. Responses measured and analysed with uni- and multivariate statistics were: anthocyanin content, antioxidant capacity and classic oenological parameters. ANOVA revealed no significant effect of treatment in the antioxidant values of RA or diphenylpicrylhydrazyl (DPPH) of wines, but a paired t-test could differentiate wines treated only with SO2 from those treated only with the novel product according to their RA values. Principal component analysis (PCA) of anthocyanin content of the treated wines gave five significant components, explaining 100% of variance and differentiating products treated only with SO2 from those treated only with new product. PCA of oenological data explained 72% of variance in the first two components and wines were clearly differentiated on the basis of SO2 or alternative treatment. In all cases, commercially acceptable red wines were produced, giving a possibility for partial substitution of SO2 by a natural product. 相似文献
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《Journal of food composition and analysis》2014,33(1):111-116
Blueberries (Vaccinium spp.) may be considered one of the best potential sources of antioxidants in the diet. This characteristic results from the presence of flavonoids (especially anthocyanins), tannins and phenolic acids in the fruits. The objective of this work was to analyze the anthocyanin stability and antioxidant activity of refrigerated whole blueberry juice stored at 4 °C for 10 d, and of fruits stored frozen (−18 °C) for 6 months, in order to determine the changes occurring during storage. The frozen fruits showed a significant increase (p < 0.05) in antioxidant activity during the 3rd month of frozen storage, followed by a decrease up to the end of the 6-month period. The juice was analyzed every other day, and the antioxidant activity changed on the 8th d of refrigerated storage, remaining stable up to the 10th d. There were significant losses of anthocyanins both in the frozen fruits (59%) and refrigerated juice (83%). The antioxidant capacity was shown to be stable during cold storage both in the case of the fruits and whole juice, whereas the anthocyanins were degraded, possibly due to oxidations and/or condensation reactions with other phenolic compounds. More studies are required to optimize the storage time and temperature of these products with respect to nutrient stability. 相似文献
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White and brown Eragrostis tef were assessed for total flavonoid and phenolic content, HPLC profile of the most common phenolics and antioxidant activity including both free and bound phenolics. Antioxidant activity was evaluated in correlation with free and bound phenolics and in vitro digestibility was determined. Content of flavonoids (0.52–1.02 mg RE/g) and phenolics (0.90–1.42 mg GAE/g) as well as antioxidant activity (1.70–4.37 μmol TEAC/g using ABTS method) was higher in free phenolic fraction. Correlation showed that bound flavonoids were not significant contributors to antioxidant activity (R2 = 0.4513 and 0.4893, respectively). The main free phenolics in brown teff were trans-p-coumaric, protocatechuic, ferulic and gallic acids, while the major free phenolics in white teff were rutin, protocatechuic and ferulic acids. The main bound phenolics in brown teff were ferulic and gallic acids, quercetin and catechin, in white teff ferulic acid, rutin, catechin and quercetin. Cooked teff showed very high level of in vitro organic matter digestibility (80.5–85.1%), whereas brown teff was significantly more digestible than white teff (P < 0.05). 相似文献
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目的 调查大肠埃希菌45种获得性耐药基因和7种可移动遗传元件遗传标记基因的存在状况,以及获得性耐药基因和可移动遗传元件遗传标记基因的相关性.方法 收集南京医科大学第一附属医院2006年3月-2008年10月患者尿液标本中分离的大肠埃希萄共60株,采用聚合酶链反应(PCR)法分析45种β-内酰胺类、氨基糖苷类、喹诺酮类获得性耐药基因和7种整合子、转座子、插入序列、接合性质粒遗传标记基因,并用指标聚类分析(SPSS法),分析β-内酰胺类、氨基糖苷类和喹诺酮类获得性耐药基因与整合子、转座子、插入序列、接合性质粒遗传标记基因的相关性.结果 60株大肠埃希菌共检测到10种获得性耐药基因(包括3种β-酰胺类获得性耐药基因、6种氨基糖苷类获得性耐药基因、1种喹诺酮类获得性耐药基因);且7种可移动遗传元件遗传标记基因均有检出,包括1种整合子基因遗传标记基因、4种转座子和插入序列基因遗传标记基因、两种接合性质粒遗传标记基因,其余35种基因均未检测到;SPSS法将上述阳性检出基因分成A和B两大簇群.结论 大肠埃希菌对抗菌药物的耐药表型与获得性耐药基因相关,且可移动遗传元件的水平转移使细菌的耐药性在同种细菌菌株之间甚至不同种细菌菌株之间得以快速传播;获得性耐药基因与可移动遗传元件遗传标记基因的指标聚类分析显示,在A簇群中,aadA5与intⅠ 1、CTX-M-55与ISEcp1、TEM-1与IS26较为相关,并有可能位于携带traA、trbC性毛基因的接合性质粒上,在B簇群中,aac(6')-Ⅰb与Tn21较为相关. 相似文献
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The effect of fertilisation rates of nitrogen: 0 (control treatment—no soil fertilisation), 40, 80 and 120 kg/ha and potassium: 0 (control treatment), 120, 150 and 180 kg/ha on the content of anthocyanins, phenolic acids and antioxidant capacity in purple–blue potato cv. ‘Blue Congo’ was examined. Anthocyanins and phenolic acids were identified and quantified by LC–MS and UPLC–PDA. Nitrogen was more effective in increasing the anthocyanin content—their quantity in tubers after nitrogen application was twice as much as that found after potassium application. Among phenolic acids, the dominant one was chlorogenic acid, the content of which significantly increased after nitrogen fertilisation at 120 kg/ha, in line with the increase in total concentration of phenolic acids and antioxidant capacity. The adjustment of nitrogen and potassium fertilisation levels during the growth of purple–blue potatoes seems to be an effective way to increase the expression of polyphenolic compounds in these cultivars. Therefore, fertilisation with N at 120 kg/ha and K at 120 and 150 kg/ha is recommended as a way to improve the content of biologically active compounds and antioxidant properties, and consequently, to enhance the nutritional value and the functionality of purple–blue potatoes. 相似文献
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杨进 《中华流行病学杂志》2010,31(5):599-600
社会经济状况(SES)与健康密切相关.财产,特别是消费型耐用物品的拥有情况能比较准确反映住户的长期生活水平和SES,而收集住户这方面资料较为客观、快速和简易.目前主元分析(principal components analysis,PCA)被越来越多用于SES指数的构建以反映住户的SES水平[1-3].我们在进行副伤寒危险因素病例对照研究时,使用PCA来构建和分析研究对象的SES. 相似文献
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Vanesa Guilln-Casla Noelia Rosales-Conrado María Eugenia Len-Gonzlez Luis Vicente Prez-Arribas Luis María Polo-Díez 《Journal of food composition and analysis》2011,24(3):456-464
The effect of E-beam irradiation on cooked and dry cured Iberian ham, minced meat, smoked salmon and soft cheese, which have different chemical compositions with respect to protein, fat, moisture, free amino acids, amino acid decomposition products and preservatives intentionally added (nitrate and nitrite), was evaluated. A decrease up to 50% in fat content was observed with the irradiation increase for cooked ham and smoked salmon. Protein was modified only in cooked ham samples, while free amino acid amounts were significantly affected in all cases. Nitrate and nitrite content were affected in cooked and Iberian ham, with losses up to 100%, and in smoked salmon. Principal component analysis (PCA) was used to model the data. The results obtained made it possible to establish that radiation doses of 6 and 8 kGy produce chemical composition changes in practically every foodstuff. At the radiation of 2 kGy, which is the dose required to reach the food safety objective (FSO), dry cured Iberian ham was the least affected food, whereas minced meat and cooked ham were the most affected. Stepwise multiple-linear regression (MLR) explained changes in nitrate and nitrite content with the radiation dose applied and the food chemical composition (especially with moisture, fat and protein). 相似文献
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In the present study, we investigated the acetylcholinesterase (AChE) inhibitory activity of the ethanolic extracts of a number of mushroom species growing in Turkey, including mainly Polyporus species (Polyporus gilvus, Polyporus sulphureus, Polyporus annosus, Polyporus radiatus, Polyporus pinicola, Polyporus volvatus, Polyporus fomentarius, Polyporus stevenii, Polyporus badius), as well as Cantharellus cibarius, Lactarius deliciosus, and Trametes versicolor. The analyses were carried out using the spectrophotometric method of Ellman in ELISA microplate reader at 500 μg/ml. Since Alzheimer's disease (AD) is associated with oxidative degeneration of cells, several methods of antioxidant activity were applied to the mushroom extracts such as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, ferrous ion-chelating effect, ferric-reducing antioxidant power (FRAP), and beta-carotene bleaching tests. Total phenol contents of the extracts were also determined by Folin-Ciocalteu reagent. In anti-AChE assay, the most active one was P. sulphureus having 31.44% of inhibition. P. voluatus showed the best scavenging effect against DPPH, while all of the extracts exerted low capacity in chelating ferrous ions and reducing ferric ion. 相似文献
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The most recent guidelines of IUPAC and AOAC recommend the analysis of specific compounds present in antioxidant fractions. For the first time, honey from different provinces of North (Nampula) and Central Mozambique (Sofala, Manica and Zambezia) was analysed considering specific flavonoids and phenolic acid profiles. Seven phenolic acids (chlorogenic, caffeic, ellagic, ferulic, gallic, p-coumaric and sinapic) and eight flavonoids (catechin, chrysin, kaempferol, luteolin, naringenin, pinocembrin, quercetin and rutin) were screened in the samples. Nampula honey had a higher content of most of these compounds and the total antioxidant activity (even reaching up to 40 mg TE/100 g) compared honey from the other provinces. Unlike in other African honeys, luteolin had the greatest impact in the flavonoid content (in some cases up to 72 mg/100 g), representing alone more than 50% of this family. Resulting from a discriminant analysis, specific flavonoids (pinocembrin, kaempferol, rutin and catechin) followed by the chlorogenic phenolic acid were the most important variables that distinguishes Nampula from the other provinces. This work underlines the importance of Mozambiquean honey as a source of natural antioxidants both of which concern the health benefits and its exploitation as a viable and sustainable income for the local population. 相似文献
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Rice wines have been consumed in China for more than 9000 years. Chinese yellow wine (CYW) is one of the traditional fermented alcoholic beverages of rice. Studies have shown that CYW improves atherosclerotic plaque in LDL-receptor-knockout mice. Rice wine consumption at a level of alcohol >12.8 g/day in Chinese women has been associated with a 34% lower risk of developing metabolic syndrome compared to non-drinkers. However, evidence for the health benefits of CYW is still very limited. In the present study, phenolic compounds, amino acids, γ-aminobutyric acid and hydroxymethylfurfural in 5-year-old Guyuelongshan CYW were characterized and quantitated as a first step in launching the studies of potential health benefits of CYW. Our results show that three of the nine phenolic compounds characterized by HPLC-DAD-ESI-MS/MS were not previously documented in the CYW. Fifteen free amino acids and γ-aminobutyric acid quantitated by the HPLC-fluorescence method and the protein assay demonstrate that CYW is a good source of amino acids (2923 μg/mL), γ-aminobutyric acid (10.1 ± 0.3 μg/mL) and peptides/proteins (4210 ± 430 μg/mL). The Trolox equivalent antioxidant capacity of CYW (1.76 ± 0.07 mM) is higher than white wines but lower than red wines. 相似文献
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《Journal of food composition and analysis》2014,33(2):169-175
Red- and purple-fleshed potatoes (Solanum tuberosum L.) are a good source of polyphenols, mainly anthocyanins as one of the most important components. The chemical composition with reducing sugars and the total polyphenol contents were analyzed in four purple potato varieties (Salad Blue, Vitelotte, Valfi, Blue Congo) and three red-fleshed potato varieties (Rosalinde, Herbie 26, Highland Burgundy Red). The anthocyanin composition of raw potato and potato crisps was characterized by high-performance liquid chromatography tandem mass spectrometry (HPLC–MS/MS) method. Moreover, the antioxidant activity was measured with the radical scavenging assays using 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical as well as ferric reducing ability of plasma assay (FRAP). In addition, colour parameters in prepared potato crisps were evaluated. Both red and purple-fleshed potato varieties contained high levels of total polyphenols (227–845 mg 100 g−1 dry weight) and anthocyanins (21–109 mg 100 g−1 dry weight). The process of frying caused degradation of anthocyanin compounds (38–70%). The HPLC–MS/MS analysis showed that pelargonidin and malvidin derivates were more stable during frying than petunidin derivatives. Although frying process affected the anthocyanin and polyphenol levels, obtained potato crisps exhibited bright intensive colour and good antioxidant activity. 相似文献