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Angers, France

Boumaza R.,Agrocampus Ouest | Huche-Thelier L.,Agrocampus Ouest | Demotes-Mainard S.,Agrocampus Ouest | Coz E.L.,Agrocampus Ouest | And 7 more authors.
Food Quality and Preference | Year: 2010

The context of ornamental horticulture is considered in order to extend the techniques of sensory and preference evaluation by taking the rosebush as a plant model. In a preliminary study (Boumaza, Demotes-Mainard, Huché-Thélier, & Guérin, 2009), a sensory evaluation was conducted in order to set up a list of attributes. Subsequently, this list was adapted to assess 10 rosebushes. After the control of the panel performance using a multivariate strategy of analysis, the average scores were used in product mapping. The evaluation of the preferences with regard to these rosebushes was undertaken: 253 subjects were asked to rank the products by decreasing order of liking. Thereafter, the preference data were subjected to an internal preference mapping and a cluster analysis. Six homogeneous segments of consumers were eventually retained. By way of performing an external preference mapping, the average ranks were regressed upon the sensory attributes using principal component regression: the preferences of 67% of the consumers were satisfactorily explained by the attributes. © 2010 Elsevier Ltd. Source

Maury C.,Laboratoire GRAPPE | Clark A.C.,Charles Sturt University | Scollary G.R.,University of Melbourne
Analytica Chimica Acta | Year: 2010

The exposure to sunlight of a Sauvignon blanc wine stored in bottles of different colours has been examined. Wine in darker bottles (Antique Green and French Green) showed considerably more colour development than wine in clear (Flint) or lighter (French Green) bottles, provided a high concentration of catechin-type phenolic compounds was present. Xanthylium pigments were identified by LC-MS as one of the main contributing phenolic pigments to the increased colour in the dark bottles. This is the first observation of yellow xanthylium pigments in a white wine. A Principal Component Analysis of the variation in absorbance measurements at Day 59 of the exposure further confirmed the importance of bottle colour on the result. One component, dominated by the darker Antique Green and Classic Green, reflected the development of colour at 440 and 520 nm. The second component, to which the Flint and French Green bottles contributed the most, was based on a decrease in the 280 nm absorbance. The implication of these results for the safe storage of wine is discussed. © 2009 Elsevier B.V. All rights reserved. Source

Renard C.M.G.C.,French National Institute for Agricultural Research | Renard C.M.G.C.,University of Avignon | Le Quere J.-M.,French National Institute for Agricultural Research | Bauduin R.,Institute Francais des Productions Cidricoles | And 4 more authors.
Food Chemistry | Year: 2011

Initial crushing and pressing operations have a major influence on the polyphenolic composition of apple juice, therefore, we have tested the impact of variations of this step using three cider apple cultivars of contrasting polyphenolic composition: Guillevic, Kermerrien and Dous Moen. Under inert atmosphere, increased temperature (between 5°C and 24°C), increased the extraction of procyanidins from fruit to juice. The crushed apples were also subjected to four conditions of oxidation: preserved from oxidation as above, short contact with air, short contact with air and mixing, long contact with air and mixing. Oxidation decreased the concentrations of native polyphenols in the juices, especially for flavan-3-ols. The golden colour of the juices was initially enhanced with increases in saturation C* and a shift of the hue angle from yellow to orange. However, for the highest oxidation state the colour became paler and more yellow. Bitterness and astringency decreased upon oxidation, probably due to increased retention of oxidised moieties. © 2010 Elsevier Ltd. Source

Clark A.C.,Charles Sturt University | Vestner J.,Charles Sturt University | Vestner J.,Wiesbaden University of Applied Sciences | Barril C.,Charles Sturt University | And 3 more authors.
Journal of Agricultural and Food Chemistry | Year: 2010

The stereochemical influence of antioxidant and flavanol compounds on oxidation processes in a model wine system was studied. The diastereoisomers, ascorbic acid and erythorbic acid, were used as antioxidants in a model wine system containing either (+)-catechin or (-)-epicatechin as the oxidizable flavanol compound. Samples were stored at 45 °C for a period of 14 days and analyzed by UV/visible spectrometry, CIELab, UPLC-PDA, and LC-MS. The results showed that less brown oxidative coloration occurred for samples with erythorbic acid for a given flavanol compound, while (+)-catechin provided less yellow coloration for a given antioxidant. Although erythorbic acid was degraded faster than ascorbic acid, it was associated with less decay in the accompanying flavanol compound. Xanthylium cation pigments were identified as the major contributor to color development. Furthermore, the production of pigment precursors, previously identified as furanone-substituted flavanols, was confirmed in all cases and their corresponding xanthylium cation pigments were lower in the presence of erythorbic acid than ascorbic acid. The results demonstrate that erythorbic acid is more efficient at minimizing oxidative color development than ascorbic acid in the model wine system. © 2009 American Chemical Society. Source

Jacob S.,Laboratoire GRAPPE | Jacob S.,Italian Agricultural Research Council | Torricelli A.,CNR Institute for Photonics and Nanotechnologies | Spinelli L.,CNR Institute for Photonics and Nanotechnologies | And 3 more authors.
Acta Horticulturae | Year: 2010

Absorption and scattering of laser light pulse passing through the fruit determine among others, the optical properties of the product. Efforts have been made in the recent past to utilize innovative techniques such as time-resolved reflectance spectroscopy (TRS) to study the quality aspects of different fruit such as nectarines. These optical properties have been well related to firmness, sugars, acids and other quality attributes. TRS measurements were performed on 'Jubileum' plums at two different wavelengths: 670 nm and 758 nm. The fruit were harvested in Norway and brought to Italy under protected conditions. After sorting the fruit by size, TRS measurements were made and the fruit were randomized for different examinations of quality aspects. It was observed that the absorption coefficient (μa) increased for both wavelengths as ripening progressed towards the melting stage of the fruit. The μa values at 670 nm were higher than those at 758 nm. The higher rate in the μa was distinguishable from the third day onwards as the fruit ripened. Similarly, it was interesting to note that the internal colour measured after destructing the fruit related well with the TRS absorption coefficient (μa), i.e., a decrease in the CIE L* (towards darker region) and b* (towards blue) value along with an increase in a* (towards red) from third day of storage. Source

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