References of "Vandenbol, Micheline"
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See detailIntersterification of rapessed oil with anhydrous milk fat and its stearin fraction. I. Modifications of composition
Aguedo, Mario ULg; Giet, Jean-Michel ULg; Hanon, Emilien ULg et al

in GCIRC Bulletin (2009), 25

Milk fat in human diet is associated with cardiovascular diseases due to its high content in saturated fatty acids and cholesterol. Most vegetable oils are much healthier as they are rich in unsaturated ... [more ▼]

Milk fat in human diet is associated with cardiovascular diseases due to its high content in saturated fatty acids and cholesterol. Most vegetable oils are much healthier as they are rich in unsaturated fatty acids (1,2). Lipase-catalysed interesterification of oils and fats has arisen as an alternative to hydrogenation or chemical processes to produce margarine and shortenings (3), notably because they do not give rise to undesirable trans fatty acids (4). The enzyme exchanges fatty acids from one triglyceride to another, resulting in a redistribution of fatty acids species. For such a reaction, the lipase of Thermomyces lanuginosa was shown to be an efficient tool in solvent-free fat blends batches and micro-aqueous conditions (5). Enzymatic interesterification can thus be used to enrich “hard” fats with unsaturated fatty acids (6,7). As an illustration, rapeseed oil (RO) (a choice source of unsaturation-rich residues) was used in the present study to enrich anhydrous milk fat (AMF) with unsaturated C18 fatty acids (FA) (oleic, linoleic and linolenic acids). Comparatively, one “harder” fraction of AMF underwent the same reaction. The physico-chemical properties modifications induced by the reaction were followed. The compositional changes are reported in this first part and the consequent physical modifications are presented in a second part. [less ▲]

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See detailInteresterification of rapeseed oil with anhydrous milk fat and its stearin fraction. II. Modifications of melting properties
Giet, Jean-Michel ULg; Aguedo, Mario ULg; Hanon, Emilien ULg et al

in GCIRC Bulletin (2009), 25

Chemical and/or physical modification of oils and fats are commonly used by food industry to widen their range of applications (1,2). Lipase-catalysed interesterification of anhydrous milk fat (AMF) and ... [more ▼]

Chemical and/or physical modification of oils and fats are commonly used by food industry to widen their range of applications (1,2). Lipase-catalysed interesterification of anhydrous milk fat (AMF) and various vegetable oils is now a well documented procedure (3-7). The purpose of this technique is to produce original structured fats with properties different from a simple blending, that may be used as spreads or introduced into pastry. The new fats contain higher amounts of polyunsaturated fatty acids (PUFA) than butter, which provides health benefits (8,9). To our knowledge only a few authors associated AMF fractionation with blending and interesterification (10,11), although this combination may be used to increase the ratio of vegetable oil in blends and thus the PUFA content of the product. The compositional changes occurring during the lipase-catalysed interesterification of AMF/rapeseed oil (RO) and AMF stearin fraction (AMFSF)/RO blends were described in the first part of this study. In the present and second part are reported the resulting changes in physical properties, especially the melting behaviour through solid fat content (SFC), dropping point (DP) and fusion profiles by differential scanning calorimetry (DSC). [less ▲]

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See detailEnzymatic interesterification of anhydrous milk fat with rapeseed and/or linseed oil: oxidative stability
Giet, Jean-Michel ULg; Aguedo, Mario ULg; Danthine, Sabine ULg et al

in Journal of Agricultural and Food Chemistry (2009), 57(15), 6787-6794

Blends of anhydrous milkfat (AMF) and linseed oil (70/30), and AMF, rapeseed oil (RO) and linseed oil (LO), 70/20/10, were submitted to enzymatic interesterification. The oxidative stability of the blends ... [more ▼]

Blends of anhydrous milkfat (AMF) and linseed oil (70/30), and AMF, rapeseed oil (RO) and linseed oil (LO), 70/20/10, were submitted to enzymatic interesterification. The oxidative stability of the blends, the interesterified (IE) blends and IE blends with 50 ppm -tocopherol added as antioxidant were studied. Samples were stored in open flasks at 60°C, 25°C and 4°C, and periodically submitted to peroxide, p-anisidine, TBA value determination and UV measurement at 232 and 268 nm. The analysis of volatile compounds was carried out by SPME for the samples stored at 60°C. Peroxides appeared to be the only significant oxidation products after 12 weeks storage at 4°C. As expected, the binary blends (BB) were more sensitive to oxidation than the ternary blends (TB). The BB were associated with increased volatile emission compared to TB. Interesterification led to variable effects on the oxidation of fat mixtures, depending on composition and temperature (beneficial effect on BB, at both 25°C and 60°C, and a rather neutral effect on TB). The IE blends exhibited higher volatile release prior to ageing. A pro-oxidant effect of -tocopherol addition was observed at 25°C on both BB and TB. At 60°C, an antioxidant effect was observed on TB. [less ▲]

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See detailInteresterification of rapeseed oil with anhydrous milk fat and its stearin fraction
Aguedo, Mario ULg; Giet, Jean-Michel ULg; Hanon, Emilien ULg et al

Poster (2009)

Rapeseed oil (RO) (a choice source of unsaturation-rich residues) was used in the present study to enrich anhydrous milk fat (AMF) with unsaturated C18 fatty acids (FA) (oleic, linoleic and linolenic ... [more ▼]

Rapeseed oil (RO) (a choice source of unsaturation-rich residues) was used in the present study to enrich anhydrous milk fat (AMF) with unsaturated C18 fatty acids (FA) (oleic, linoleic and linolenic acids). Comparatively, one “harder” fraction of AMF underwent the same reaction. The physico-chemical properties modifications induced by the reaction were followed. The compositional changes are reported in this first part and the consequent physical modifications are presented in a second part. [less ▲]

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See detailInteresterification of rapeseed oil with anhydrous milk fat and its stearin fraction
Giet, Jean-Michel ULg; Aguedo, Mario ULg; Hanon, Emilien ULg et al

Poster (2009)

The compositional changes occurring during the lipase-catalysed interesterification of AMF/rapeseed oil (RO) and AMF stearin fraction (AMFSF)/RO blends were described in the first part of this study. In ... [more ▼]

The compositional changes occurring during the lipase-catalysed interesterification of AMF/rapeseed oil (RO) and AMF stearin fraction (AMFSF)/RO blends were described in the first part of this study. In the present and second part are reported the resulting changes in physical properties, especially the melting behaviour through solid fat content (SFC), dropping point (DP) and fusion profiles by differential scanning calorimetry (DSC). [less ▲]

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See detailEnrichment of Anhydrous Milk Fat in Polyunsatured Fatty Acid Residues
Aguedo, Mario ULg; Hanon, Emilien ULg; Danthine, Sabine ULg et al

Poster (2009)

Lipozyme TL IM was used in a solvent-free batch, microaqueous system for enzymatic interesterification of anhydrous milkfat (AMF) with linseed oil (LO) in binary blends and with rapeseed oil (RO) in one ... [more ▼]

Lipozyme TL IM was used in a solvent-free batch, microaqueous system for enzymatic interesterification of anhydrous milkfat (AMF) with linseed oil (LO) in binary blends and with rapeseed oil (RO) in one ternary blend. [less ▲]

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See detailCalorimetric study of milk fat/rapeseed oil blends and their interesterification products
Aguedo, Mario ULg; Giet, Jean-Michel ULg; Hanon, Emilien ULg et al

in European Journal of Lipid Science and Technology [=EJLST] (2009), 111(4), 376-385

Milk fat (MF) and rapeseed oil (RO) blends were analyzed by differential scanning calorimetry (DSC). It was shown that peak and onset temperatures can be used to determine the percentage of each fat in ... [more ▼]

Milk fat (MF) and rapeseed oil (RO) blends were analyzed by differential scanning calorimetry (DSC). It was shown that peak and onset temperatures can be used to determine the percentage of each fat in the blend and that the relative enthalpy of one peak assigned to low-melting triacylglycerols (TAG) can also be used to determine the percentage of RO in the blend. A linear relation was also established between IMF content of the blend and its dropping point (DP), indicating that DP can be linearly related with the above DSC data. A blend of MF/RO 70 : 30 (wt/wt) was then chosen as a model system for enzymatic interesterification (EIE). The applicability of DSC analyses to EIE products was checked and a correct correlation could be established between DSC values and the interesterification degree and DP. Among the data from the DSC profiles, the peak associated with low-melting TAG was the best indicator of the reaction course. In the same way, a high-melting MF stearin fraction was interesterified. with RO. In that case, onset temperatures and peak "a" were better reaction indicators than for the interesterified MF/RO blend. We therefore suggest that values from DSC endotherms could be used to monitor EIE of fat blends. [less ▲]

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See detailIsolation and biomass production of a Saccharomyces cerevisiae strain binding copper and zinc ions
Stroobants, Aurore ULg; Delroisse, Jean-Marc; Delvigne, Frank ULg et al

in Applied Biochemistry and Biotechnology (2009), 157(1),

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See detailEnrichment of anhydrous milk fat in polyunsaturated fatty acid residues from linseed and rapeseed oils through enzymatic interesterification
Aguedo, Mario ULg; Hanon, EMILIEN ULg; Danthine, Sabine ULg et al

in Journal of Agricultural and Food Chemistry (2008), 56(5), 1757-1765

Lipozyme TL IM was used in a solvent-free batch and microaqueous system for enzymatic interesterification of anhydrous milkfat (AMF) with linseed oil (LO) in binary blends and with rapeseed oil (RO) in ... [more ▼]

Lipozyme TL IM was used in a solvent-free batch and microaqueous system for enzymatic interesterification of anhydrous milkfat (AMF) with linseed oil (LO) in binary blends and with rapeseed oil (RO) in one ternary blend. The aim was to obtain and characterize physicochemically fats enriched with unsaturated C-18 fatty acids (oleic, linoleic, and, especially, linolenic acids) from natural vegetable oils. Binary blends of AMF/LO 100/0, 90/10, 80/20, 70/30, and 60/40 (w/w) were interesterified. The change in triacylglycerol (TAG) profiles showed that quasi-equilibrium conditions were reached after 4-6 h of reaction. Free fatty acid contents < 1%. The decrease in solid fat content and in dropping point temperature obtained with increasing content of LO and interesterification resulted in good plastic properties for the products originating from the blends 70/30 and 60/40. This was confirmed by textural measurements. Melting profiles determined by differential scanning calorimetry showed complete disappearance of low-melting TAGs from LO and the formation of intermediary species with a lower melting temperature. Oxidative stability of the interesterified products was diminished with increasing LO content, resulting in low oxidation induction times. A ternary blend composed of AMF/RO/LO 70/20/10 gave satisfactory rheological and oxidative properties, fulfilling the requirements for a marketable spread and, moreover, offering increased potential health benefits due to the enriched content in polyunsatured fatty acid residues. [less ▲]

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See detailCharacterization of a novel aphid prenyltransferase displaying dual geranyl/farnesyl diphosphate synthase activity
Vandermoten, Sophie ULg; Charloteaux, Benoît ULg; Santini, S. et al

in FEBS Letters (2008), 582(16), 19281934

We report on the cDNA cloning and characterization of a novel short-chain isoprenyl diphosphate synthase from the aphid Myzus persicae. Of the three IPPS cDNAs we cloned, two yielded prenyltransferase ... [more ▼]

We report on the cDNA cloning and characterization of a novel short-chain isoprenyl diphosphate synthase from the aphid Myzus persicae. Of the three IPPS cDNAs we cloned, two yielded prenyltransferase activity following expression in Escherichia coli; these cDNAs encode identical proteins except for the presence, in one of them, of an N-terminal mitochondrial targeting peptide. Although the aphid enzyme was predicted to be a farnesyl diphosphate synthase by BLASTP analysis, rMpIPPS, when isopentenyl diphosphate and dimethylallyl diphosphate are supplied as substrates, typically generated geranyl diphosphate (C10) as its main product, along with significant quantities of farnesyl diphosphate (C15). Analysis of an MpIPPS homology model pointed to substitutions that could confer GPP/FPP synthase activity to the aphid enzyme. [less ▲]

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See detailSeparate And Combined Disruptions Of Two Exo-Beta-1,3-Glucanase Genes Decrease The Efficiency Of Pichia Anomala (Strain K) Biocontrol Against Botrytis Cinerea On Apple
Friel, D.; Pessoa, Nmg.; Vandenbol, Micheline ULg et al

in Molecular Plant-Microbe Interactions [=MPMI] (2007), 20(4), 371-379

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See detailEnrichment of anhydrous milk fat in polyunsatured fatty acid residues from linseed and rapeseed oil through enzymatic interesterification
Aguedo, Mario ULg; Hanon, Emilien ULg; Danthine, Sabine ULg et al

Poster (2007)

The interesterification, or ester exchange, between two fats leads to the rearrangement of acyl moieties in both. The use of a sn-1,3-specific lipase confines the exchange of fatty acid residues to the sn ... [more ▼]

The interesterification, or ester exchange, between two fats leads to the rearrangement of acyl moieties in both. The use of a sn-1,3-specific lipase confines the exchange of fatty acid residues to the sn-1 and sn-3 positions of triacylglycerides (TAG), generating products with characteristics that cannot be obtained through a chemical process or a blending. Such reactions require mild conditions with no solvent needed and they yield no unhealthful trans fatty acids, justifying the stepped-up interest of enzymatic interesterification for the production of margarines and other food fats. The aim of this work was to use enzymatic interesterification to enrich anhydrous milk fat (AMF) with unsaturated fatty acid C18 residues from linseed oil (LO) and eventually from rapeseed oil (RO) through some binary blends and one ternary blend. For that, the 1,3-specific lipase from Thermomyces lanuginosa (Lipozyme TL IM) was used in solvent-free batch and micro-aqueous reactions and fat blends with different mass ratios were tested. The evolution of TAG profiles, of interesterification degre (ID) and of free fatty acids (FFA), was followed along the reactions. Determination of dropping points (DP) and solid fat contents (SFC) enabled a rheological characterization of the products. The end products were also characterized for their oxidative stability and their textural properties. [less ▲]

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See detailMutational Analysis Of The Tre2 Oncogene Encoding An Inactive Rabgap
Bizimungu, C.; Thomas, Annick ULg; Brasseur, Robert ULg et al

in Biotechnology Letters (2007), 29(12), 1927-37

The TRE2 oncoprotein is structurally related to the RabGAP (GTPase-activating protein) family. However, TRE2 seems enzymatically inactive. Two regions are important for its lack of GAP activity. First ... [more ▼]

The TRE2 oncoprotein is structurally related to the RabGAP (GTPase-activating protein) family. However, TRE2 seems enzymatically inactive. Two regions are important for its lack of GAP activity. First, the TBC domain, forming the catalytically active domain of RabGAPs, is non-functional in the oncoprotein. Also involved in TRE2 inactivity is the 93-aa region flanking the TBC domain on the C-terminal side. In order to identify the residues responsible for non-functionality, we performed hydrophobic cluster analysis of the oncoprotein sequence, combined with secondary structure prediction, receptor-binding domain analysis, and a tilted peptide calculation. These analyses were complemented with site-directed and random mutagenesis experiments. On the basis of our data, we hypothesize that the lack of secondary structure of the region flanking the TBC domain in TRE2 may explain why this region plays a role in the lack of GAP activity, even when a potentially functional TBC domain is present. [less ▲]

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See detailMolecular cloning and functional expression of a new aphid isoprenyl diphosphate synthase
Vandermoten, Sophie ULg; Beliveau, Catherine; Sen, Stephanie et al

Poster (2006, December 18)

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See detailMolecular cloning and functional expression of a new aphid isoprenyl diphosphate synthase
Vandermoten, Sophie ULg; Beliveau, C.; Sen, S. et al

in Archives Internationales de Physiologie et de Biochimie (2006, December), 190

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