Detection of the presence of refined hazelnut oil in refined olive oil by fluorescence spectroscopy     

Sayago A  García-Gonzalez DL  Morales MT  Aparicio R 《Journal of agricultural and food chemistry》2007,55(6):2068-2071

The fluorescence spectroscopy technique has been tested as regards its ability to differentiate between refined hazelnut and olive oils. Classification of these oils based on their excitation-emission fluorescence spectra data (spectral range 300-500 nm of the excitation spectra at lambdaem=655 and spectral range 650-900 of the emission spectra at lambdaex=50 nm) was performed using principal component analysis and artificial neural networks. Both methods provided good discrimination between the refined hazelnut and olive oils. The results have also pointed out the possibilities of a spectrofluorimetric method joined to multivariate analysis, to differentiate refined oils, and even to detect the presence of refined hazelnut oils in refined olive oils at percentages higher than 9%.  相似文献   

Analysis of organophosphorus pesticides in dried ground ginseng root by capillary gas chromatography-mass spectrometry and -flame photometric detection     

Wong JW  Hennessy MK  Hayward DG  Krynitsky AJ  Cassias I  Schenck FJ 《Journal of agricultural and food chemistry》2007,55(4):1117-1128

A method was developed to determine organophosphorus pesticides (OPs) in dried ground ginseng root. Pesticides were extracted from the sample using acetonitrile/water saturated with salts, followed by solid-phase dispersive cleanup, and analyzed by capillary gas chromatography with electron ionization mass spectrometry in selective ion monitoring mode (GC-MS/SIM) and flame photometric detection (GC-FPD) in phosphorus mode. The detection limits for most of the pesticides were 0.025-0.05 microg/g using GC-FPD but were analyte-dependent for GC-MS/SIM, ranging from 0.005 to 0.50 microg/g. Quantitation was determined from 0.050 to 5.0 microg/g with r 2 > 0.99 for a majority of the pesticides using both detectors. Recovery studies were performed by fortifying the dried ground ginseng root samples to concentrations of 0.025, 0.1, and 1.0 microg/g, resulting in recoveries of >90% for most pesticides by GC-FPD. Lower (<70%) and higher (>120%) recoveries were most likely from complications of pesticide lability or volatility, matrix interference, or inefficient desorption from the solid-phase sorbents. There was difficulty in analyzing the ginseng samples for the OPs using GC-MS at the lower fortification levels for some of the OPs due to lack of confirmation. GC-FPD and GC-MS/SIM complement each other in detecting the OPs in dried ground ginseng root samples. This procedure was shown to be effective and was applied to the analysis of OPs in ginseng root samples. One particular sample, a ground and dried American ginseng (Panax quinquefolius) root sample, was found to contain diazinon quantified at approximately 25 microg/kg by external calibration using matrix-matched standards or standard addition using both detectors. The advantage of using both detectors is that confirmation can be achieved using GC-MS, whereas the use of a megabore column in GC-FPD can be used to quantitate some of the nonpolar OPs without the use of matrix-matched standards or standard addition.  相似文献   

The influence of fruit and vegetable intake on the nutritional status and plasma homocysteine levels of institutionalised elderly people     

Bermejo LM  Aparicio A  Andrés P  López-Sobaler AM  Ortega RM 《Public health nutrition》2007,10(3):266-272

OBJECTIVE: To determine the difference in the nutritional status of elderly people depending on their consumption of fruits and vegetables, and to study the possible association between the consumption of these foods and different cardiovascular risk factors, especially total plasma homocysteine (t-Hcys) levels. DESIGN, SETTING AND SUBJECTS: A cross-sectional study in 152 institutionalised older people from Madrid aged > or = 65 years. Food and nutrient intakes were recorded over 7 days using the 'precise individual weighing' method. The weight, height, and waist and hip circumferences of all subjects were recorded, as were their alpha-erythrocyte glutathione reductase, serum B6, B12 and folate levels, erythrocyte folate levels, t-Hcys levels, serum lipids and blood pressure. The experimental population was then divided into tertiles depending on the serving intake of fruit and vegetables (T1, < 2.29 servings day(-1); T2, 2.29-2.79 servings day(-1); and T3, >2.79 servings day(-1)). RESULTS: Compared with T1 subjects, T3 subjects showed consumptions of cereals, pulses, meat, fish and eggs closer to those recommended (P < 0.05). In addition, the contribution of their diet towards covering the recommended daily intake of vitamin B1, niacin, vitamin B6, folic acid, vitamin C, B12, vitamin A, and P, Mg, Zn and Fe was higher. The intake of fibre increased with consumption of fruit and vegetables (r = 0.6839, P < 0.001). T3 subjects also had better serum and erythrocyte folate levels than T1 and T2 subjects (P < 0.05). A positive correlation was found between the consumption of fruit and vegetables and serum folate (r = 0.2665, P < 0.01) and with erythrocyte folate levels (r = 0.2034, P < 0.05), and a negative correlation with t-Hcys (r = -0.2493, P < 0.01). CONCLUSIONS: Greater consumption of fruit and vegetables is associated with better food habits, increased vitamin and mineral intakes and lower t-Hcys levels. Considering that the fruit and vegetable intake in Spanish elderly people is very low, it is recommended that the consumption of fruits and vegetables by elderly people be increased.  相似文献   

Pan‐continental invasion of Pseudorasbora parva: towards a better understanding of freshwater fish invasions     

Rodolphe E Gozlan  Demetra Andreou  Takashi Asaeda  Kathleen Beyer  Rachid Bouhadad  Dean Burnard  Nuno Caiola  Predrag Cakic  Vesna Djikanovic  Hamid R Esmaeili  Istvan Falka  Duncan Golicher  Akos Harka  Galina Jeney  Vladimír Kováč  Jiří Musil  Annamaria Nocita  Meta Povz  Nicolas Poulet  Tomas Virbickas  Christian Wolter  A Serhan Tarkan  Elena Tricarico  Teodora Trichkova  Hugo Verreycken  Andrzej Witkowski  Chun Guang Zhang  Irene Zweimueller  J Robert Britton 《Fish and Fisheries》2010,11(4):315-340

In recent years, policy‐makers have sought the development of appropriate tools to prevent and manage introductions of invasive species. However, these tools are not well suited for introductions of non‐target species that are unknowingly released alongside intentionally‐introduced species. The most compelling example of such invasion is arguably the topmouth gudgeon Pseudorasbora parva, a small cyprinid species originating from East Asia. A combination of sociological, economical and biological factors has fuelled their rapid invasion since the 1960s; 32 countries (from Central Asia to North Africa) have been invaded in less than 50 years. Based on a combination of monitoring surveys (2535 populations sampled) and literature reviews, this paper aims to quantify and characterise important invasion parameters, such as pathways of introduction, time between introduction and detection, lag phase and plasticity of life history traits. Every decade, five new countries have reported P. parva introduction, mainly resulting from the movement of Chinese carps for fish farming. The mean detection period after first introduction was 4 years, a duration insufficient to prevent their pan‐continental invasion. High phenotypic plasticity in fitness related traits such as growth, early maturity, fecundity, reproductive behaviour and the ability to cope with novel pathogens has predisposed P. parva to being a strong invader. The Pseudorasbora parva invasion has provided quantitative data for the development of 1) early warning systems across different spatial scales; 2) rapid eradication programmes prior to natural spread in open systems and 3) sound risk assessments with emphasis on plasticity of life history traits.  相似文献