Determination of carbon-13 content of sugars of fruit and vegetable juices
TL;DR: An inter-laboratory comparison, organized by a working group of the technical committee for the analysis of fruit and vegetable juices of the European Commission of Standardization (CEN/TC 174), was carried out between fifteen laboratories in seven European countries on the determination of the carbon-13 content of sugars of fruit juices.
About: This article is published in Analytica Chimica Acta.The article was published on 1993-01-08. It has received 66 citations till now.
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TL;DR: The development of the stable isotope analysis has gained increasing importance in authenticity control of food and food ingredients as mentioned in this paper, and the progress in instrumentation during the last few decades is described.
Abstract: Within the last few years, stable isotope analysis has gained increasing importance in authenticity control of food and food ingredients. The development of the methodology from its start in the geological sciences is reviewed, the requirements and the specific features of the technique in the area of food quality assessment are outlined, and the progress in instrumentation during the last few decades is described. Scope and limits of the analysis of stable isotope ratios to assess the quality and to determine the origin are demonstrated for foods, such as fruit juice, wine, spirits, or beer. The classical approaches investigating hydrogen, carbon and oxygen isotopes as well as strategies including elements, such as nitrogen and sulfur, are reviewed. The present state of the art and future possibilities of the methodology are discussed.
285 citations
TL;DR: Stable isotope ratio mass spectrometry (IRMS) is an additional technique that can be utilised to test a given hypothesis and shows the potential to be able to individualise a range of materials of forensic interest.
255 citations
TL;DR: This review covers two important techniques, high resolution nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry, used to characterize food products and detect possible adulteration of wine, fruit juices, and olive oil, all important products of the Mediterranean Basin.
Abstract: This review covers two important techniques, high resolution nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS), used to characterize food products and detect possible adulteration of wine, fruit juices, and olive oil, all important products of the Mediterranean Basin. Emphasis is placed on the complementary use of SNIF-NMR (site-specific natural isotopic fractionation nuclear magnetic resonance) and IRMS (isotope-ratio mass spectrometry) in association with chemometric methods for detecting the adulteration.
173 citations
TL;DR: EPS production by L. sanfranciscensis in wheat doughs was confirmed by the determination of delta (13)C values of water soluble polysaccharides after the addition of naturally labeled sucrose, originating from C(3)- and C(4)-plants.
Abstract: The exopolysaccharide (EPS) produced from sucrose by Lactobacillus sanfranciscensis LTH2590 is predominantly composed of fructose. EPS production during sourdough fermentation has the potential to affect rheological properties of the dough as well as the volume, texture, and keepability of bread. Its in situ production by L. sanfranciscensis LTH2590 was demonstrated during sourdough fermentation after the hydrolysis of water soluble polysaccharides. In wheat and rye doughs with sucrose addition the concentration of fructose in the hydrolysate of polysaccharides was significantly higher than that in the hydrolysate of control doughs or doughs without sucrose addition. EPS production by L. sanfranciscensis in wheat doughs was confirmed by the determination of δ 13C values of water soluble polysaccharides after the addition of naturally labeled sucrose, originating from C3- and C4-plants. In rye doughs, evidence for EPS production with the isotope technique could be demonstrated only by the determination of ...
153 citations
TL;DR: The authenticity of vegetable oils consumed in Slovenia and Croatia was investigated by carbon isotope analysis of the individual fatty acids by the use of gas chromatography-combustion-isotope ratio mass spectrometry (GC/C/IRMS), and through carbon isotopes of the bulk oil.
Abstract: The authenticity of vegetable oils consumed in Slovenia and Croatia was investigated by carbon isotope analysis of the individual fatty acids by the use of gas chromatography-combustion-isotope ratio mass spectrometry (GC/C/IRMS), and through carbon isotope analysis of the bulk oil. The fatty acids from samples of olive, pumpkin, sunflower, maize, rape, soybean, and sesame oils were separated by alkaline hydrolysis and derivatized to methyl esters for chemical characterization by capillary gas chromatography/mass spectrometry (GC/MS) prior to isotopic analysis. Enrichment in heavy carbon isotope ((13)C) of the bulk oil and of the individual fatty acids are related to (1) a thermally induced degradation during processing (deodorization, steam washing, or bleaching), (2) hydrolytic rancidity (lipolysis) and oxidative rancidity of the vegetable oils during storage, and (3) the potential blend with refined oil or other vegetable oils. The impurity or admixture of different oils may be assessed from the delta(13)C(16:0) vs. delta(13)C(18:1) covariations. The fatty acid compositions of Slovenian and Croatian olive oils are compared with those from the most important Mediterranean producer countries (Spain, Italy, Greece, and France).
97 citations
References
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TL;DR: In this paper, Niee's and Solenhofen standards were compared to the Chicago PDB standard for carbon and oxygen isotope ratios, and the correction factors for instrumental effects and for the nature of the mass spectra were derived.
4,071 citations
TL;DR: The fractionation of carbon isotopes that occurs during photosynthesis is one of the most useful techniques for investigating the efficiency of CO2 uptake and indicates that different strategies are needed for improving wateruse efficiency in different kinds of plants.
Abstract: he efficiency of photosynthesis continues to interest biochemists, biologists, and plant physiologists. Scientists interested in CO2 uptake are concerned about the extent to which the uptake rate is limited by such factors as stomatal diffusion and the chemistry of the CO2 absorption process. The fractionation of carbon isotopes that occurs during photosynthesis is one of the most useful techniques for investigating the efficiency of CO2 uptake. Atmospheric carbon dioxide contains approximately 1.1% of the nonradioactive isotope carbon-13 and 98.9% of carbon-12. During photosynthesis, plants discriminate against C because of small differences in chemical and physical properties imparted by the difference in mass. This discrimination can be used to assign plants to various photosynthetic groups. The isotope fractionation also reflects limitations on photosynthetic efficiency imposed by the various diffusional and chemical components of CO2 uptake. When analyzed in detail, this fractionation provides information .about water use efficiency and indicates that different strategies are needed for improving wateruse efficiency in different kinds of plants. Isotope fractionation in simple physical and chemical processes is well understood and is commonly Current studies include
2,019 citations
TL;DR: Le rapport isotopique C13/C12 ne permet pas de detecter l'addition de sucre de betterave (seulement du sirop de glucose ou du Sucre de canne).
Abstract: Le rapport isotopique C13/C12 ne permet pas de detecter l'addition de sucre de betterave (seulement du sirop de glucose ou du sucre de canne). La mise en evidence de l'addition du sucre de betterave necessite l'analyse du rapport H2/H1
78 citations
TL;DR: In this article, a methode d'analyse isotopique for detection de l'adulteration du jus d'orange par du sucre de betterave is described.
Abstract: Description d'une methode d'analyse isotopique pour la detection de l'adulteration du jus d'orange par du sucre de betterave
43 citations
TL;DR: More than 500 carbohydrate samples have been characterised by hydrogen, carbon and oxygen isotopic parameters measured on ethanol and water resulting from controlled fermentation, and the results have been analyzed in the multidimensional space of these isotopic variables.
Abstract: More than 500 carbohydrate samples have been characterised by hydrogen, carbon and oxygen isotopic parameters measured on ethanol and water resulting from controlled fermentation. Different chemical states of the carbohydrate pool have been considered: polysaccharides from cereals, tubers and leguminosae (maize, sorghum, rice, wheat, barley, potato, bean), glucose, fructose and sucrose from fruits (pineapple, citrus, apple, soft fruits), sucrose from sugar plants (beet, cane). The overall carbon-13 content of ethanol and the deuterium and oxygen-18 contents of water before fermentation were determined by mass spectrometry of isotope ratios whereas the investigation of site-specific natural isotope fractionation by deuterium NMR has provided access to the deuterium contents in the methyl (I) and methylene (II) sites of ethanol. The results have been analysed in the multidimensional space of these isotopic variables. Hierarchical clustering, principal component and discriminant analyses have been performed. Among fruits, for example, the pineapple group exhibits a 100% discrimination with respect to the apple and citrus groups which are themselves well distinguished. A still higher discrimination is reached between the three groups, citrus, cane and beet, and the addition of 10% exogenous cane or beet sucrose to citrus juice is unambiguously detected.
38 citations