References of "Richard, Gaetan"
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See detailHepatoprotective and anti-diabetic activities of Fraxinus angustifoliaVahl extracts in animal models: Characterization by HPLC analysis
Medjahed, Zineb; Atmani-Kilani, Dina; Fauconnier, Marie-Laure ULg et al

in Turkish Journal of Medical Sciences (in press)

Background and aim: The present study was designed to explore anti-diabetic and hepato-protective potentials of Fraxinus angustifolia leaf (FAL) and bark (FAB) extracts in vivo.

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See detailMinor compounds and oxidative stability of mono-varietal virgin olive oils produced in eastern of Morocco
Mansouri, Farid; Benmoumen, Abdessamad; Richard, Gaetan ULg et al

in Food Chemistry (in press)

The aim of this study is to characterize monovarietal virgin olive oils (VOOs) of new high-density plantings system of three cultivars (Arbequina, Arbosana and Koroneiki) which have been recently ... [more ▼]

The aim of this study is to characterize monovarietal virgin olive oils (VOOs) of new high-density plantings system of three cultivars (Arbequina, Arbosana and Koroneiki) which have been recently introduced in the eastern mediterranean region of Morocco. In this study, we have also conducted comparison between those monovarietal VOOs and olive oil of the local olive cultivar Picholine marocaine. Monovarietal VOOs characterization has been carried out by analysing several parameters, including quality index and olive oil stability to oxidation. Significant differences between the analysed olive oils were highlighted. They depend on cultivars and technological conditions of processing. We have noticed that Koroneiki olive oil have higher content of phenols (459.48 mg kg-1) and have the best value of oxidative stability (93.16 h). On the other hand Arbrosana’s VOO has low content of total phenols (260.85 mg kg-1) but it was distinguished by its higher content of alpha-tocopherol (460.07 mg kg-1). In addition, ten phenolic compounds present in virgin olive oils, were identified and quantitatively assessed by HPLC. Hydroxytyrosol, tyrosol, luteoline, pinoresinol and apigenin were the main phenolic compounds in those analyzed monovarietal VOOS. [less ▲]

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See detailCharacterization of monovarietal virgin olive oils from introduced cultivars in eastern Morocco
Mansouri, Farid ULg; Benmoumen, A.; Richard, Gaetan ULg et al

in Rivista Italiana Sostanze Grasse (2016), 93

The aim of this study was to characterize monovarietal virgin olive oils (VOOs) of new high-density planting system of three European cultivars (Arbequina, Arbosana and Koroneiki), recently introduced in ... [more ▼]

The aim of this study was to characterize monovarietal virgin olive oils (VOOs) of new high-density planting system of three European cultivars (Arbequina, Arbosana and Koroneiki), recently introduced in eastern Morocco. VOOs’ characterization has been carried out by analyzing several parameters, such as quality indexes, fatty acid contents, minor components, and olive oils’ oxidative stability index (OSI). In this study, we have also conducted a comparison between these monovarietal VOOs and olive oils of autochthones cultivar Picholine marocaine. Significant differences between the analyzed VOOs were highlighted. Koroneiki’s VOO had a high phenols content (493.66 mg/kg) and, consequently, the best oxidative stability (94.83 h); Arbrosana’s VOO was distinguished by its abundance of α-tocopherol (460.07 mg/kg) and by an intermediate OSI (64.83 h). In addition, results showed, firstly, that in all the analyzed oils decarboxymethyl ligstroside aglycone and decarboxymethyl oleuropein aglycone were the main phenolic compounds, and, secondly, that VOOs of Koroneiki and Arbosana seem to have similar profiles, with a high content of natural antioxidants and a high oleic/linoleic ratio, thus boasting a better shelf life. [less ▲]

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See detailPhysicochemical properties and thermal behaviour of African wild mango (Irvingia gabonensis) seed oil.
Yamoneka, Juste; Malumba Kamba, Paul ULg; Blecker, Christophe ULg et al

Poster (2015, March 15)

African wild mango (lrvingia gabonensis) is now recognized for its numerous food and medicinal uses. This plant produces seeds rich in fat, which is traditionally used as a soup thickener. in the present ... [more ▼]

African wild mango (lrvingia gabonensis) is now recognized for its numerous food and medicinal uses. This plant produces seeds rich in fat, which is traditionally used as a soup thickener. in the present study, the proximate composition of seeds from lrvingia gabonensis is reported. The oil from the seeds was then solvent extracted; its fatty acid (FA) and triacylglycerol (TG) profiles were determined. Besides this chemical characterization, the melting and crystallization behaviour of the extracted fat was studied by pNMR, DSC and X-ray diffraction. The result of this investigation showed that the seeds from lrvingia gabonensis (IG) represent an important source of lipids (69-75%), rich in myristic (49.8%) and lauric acid (37%). This fat can be classified among "lauric fats". IG oil presents a good oxidative stability due to its low content in unsaturated fatty acid. The melting profiles of IG oil indicates that a high amount of fat remains solid at temperatures up to 30°C; the complete melting was detected at around 40C. The most stable polymorph of this fat is the β'1 -form. [less ▲]

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See detailL'assiette du futur : surprises, passion, innovation et... gourmandise
Goffin, Dorothée ULg; Richard, Gaetan ULg

Conference given outside the academic context (2015)

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See detailInteractions of natural rhamnolpids produced by Pseudomonas aeruginosa with plant model membranes
Polo Lozano, Damien ULg; Nasir, Mehmet Nail ULg; Deleu, Magali ULg et al

Poster (2015, January 30)

It is well known that chemical pesticides have harmful effects on human health and environment. In this context, the interest for alternative products such as biopesticides is increasing. Among them ... [more ▼]

It is well known that chemical pesticides have harmful effects on human health and environment. In this context, the interest for alternative products such as biopesticides is increasing. Among them, elicitors act on the plants by inducing systemic resistance against diseases caused by fungal, viral, bacterial agents and insects. Rhamnolipids are surface active molecules produced mainly by various strains of the bacterium Pseudomonas aeruginosa. These secondary metabolites are composed of one to three fatty acids with various chain lengths linked through a glycosidic bond to one or two rhamnose moieties. The fatty acids are linked together through an ester bond. These molecules have shown several biological activities including plant defense stimulation. It has been suggested that this elicitor activity could be related to an interaction of rhamnolipids with the lipid bilayer of the plant plasma membrane (PPM) and lead to its destabilization, which can activate the plant defense signaling pathways. In this context, interactions of two rhamnolipids (Rha-C10-C10 and Rha-Rha-C10-C10) with biomimetic membranes of PPM such as Langmuir monolayers and multilayers were investigated using biophysical and in silico approaches. [less ▲]

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See detailBiochemical characterisation of the seed oils of four safflower (Carthamus tinctorius) varieties grown in north-eastern of Morocco
Ben Moumen, Abdessamad; Mansouri, Farid; Richard, Gaetan ULg et al

in International Journal of Food Science & Technology (2015)

The quality of the oil of four safflower varieties, originating from Spain (Rancho), India (Sharda) and Morocco (Cartamar and Cartafri), which were cultivated at the experimental station in Oujda (a semi ... [more ▼]

The quality of the oil of four safflower varieties, originating from Spain (Rancho), India (Sharda) and Morocco (Cartamar and Cartafri), which were cultivated at the experimental station in Oujda (a semi-arid region of eastern Morocco) was evaluated through analysis of their phenolic and carotenoid contents. The composition of the phenolic compounds of safflower oil has not yet been documented. Therefore, in this preliminary study, Thirty different phenolic compounds were identified, and significant differences between the oil varieties were observed (P < 0.05). In the seed oil from the Rancho and Sharda safflower varieties, the main phenolic compound was trans-chalcone, representing 13.45% and 11.8%, respectively, of the total phenolics, whereas in Cartamar and Cartafri oils, naringin accounted for 26.82% and 16.5%, respectively, of the total phenolics. The total carotenoid contents ranged from 1.13 mg/kg (Rancho) to 1.34 mg/kg (Cartamar and Cartafri).We observed that b-cryptoxanthin (0.31–0.37 mg/kg) and b-carotene (0.3–0.35 mg/kg) were the predominant carotenoids in all of the safflower oils that were studied. [less ▲]

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See detailPhytosterols composition of virgin olive oils from cultivars introduced in eastern Morocco in comparison to Picholine Marocaine
Mansouri, F.; Ben Moumen, A.; Richard, Gaetan ULg et al

in Journal of Materials and Environmental Science (2015), 6(8), 2322-2329

The aim of this study is to characterize monovarietal virgin olive oils (VOOs) of three European cultivars (Arbequina, Arbosana and Koroneiki), grown under high-density plantation system in eastern ... [more ▼]

The aim of this study is to characterize monovarietal virgin olive oils (VOOs) of three European cultivars (Arbequina, Arbosana and Koroneiki), grown under high-density plantation system in eastern Morocco, by comparison of their phytosterols profiles. First, physicochemical properties of these monovarietal VOOs as well as their contents of pigments and phenols were analyzed. Then, VOOs phytosterols profiles were determined by GC-FID, and show that b-sitosterol is the most abundant sterol which represent 75 to 79 % of total phytosterols in analyzed olive oils. On the basis of these results, a comparison between these monovarietal VOOs and olive oil of Picholine marocaine (autochthonous olive tree) has been carried out, and shows that majority of analytical parameters presented statistically significant differences (p < 0.05). The examined olive varieties produce excellent oils with a chemical composition within the regulatory limits and an appreciable amount of phytosterols. In addition, results showed that, total phytosterols content of olive oil from Picholine marocaine is significantly higher (2348.78 mg kg-1) than values observed for VOOs of European cultivars, which range from 1595 to 1971mg kg-1 but, Koroneiki’s VOO has the highest phenols content (493.66 mg kg-1) and the highest pigments content (3.94 and 2.17 mg kg-1 respectively for chlorophylls for carotenoids). Lastly, according to VOOs' content of minor components (phenols, pigments and phytosterols), the hierarchical cluster analysis shows a good discrimination between olive tree varieties. [less ▲]

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See detailVariations in the phytosterol and tocopherol compositions and the oxidative stability in seed oils from four safflower (Carthamus tinctorius L) varieties grown in north-eastern Morocco
Ben Moumen, Abdessamad; Mansouri, Farid; Richard, Gaetan ULg et al

in International Journal of Food Science and Technology (2015), 50(10), 22642270

Phytosterol and tocopherol contents and oxidative stability were evaluated from seeds oils of four safflower (Carthamus tinctorius L) varieties originating from Spain (Rancho), India (Sharda) and Morocco ... [more ▼]

Phytosterol and tocopherol contents and oxidative stability were evaluated from seeds oils of four safflower (Carthamus tinctorius L) varieties originating from Spain (Rancho), India (Sharda) and Morocco (Cartamar and Cartafri), which were cultivated at the experimental station in Oujda (a semi-arid region of eastern Morocco). Total phytosterols ranged from 3640 to 4140 mg kg -1. GC analysis allowed the identification of nine compounds, of which b-sitosterol was the major component. Total tocopherols ranged from 461.56 to 499.68 mg kg -1. HPLC analysis allowed the identification of three compounds,a-tocopherol (99.45%–98.84%), b-tocopherol (0.94%–0.5%) and c-tocopherol (0.21%–0.01%). Oxidative stability study showed that Sharda had the lowest induction period of 2.3 h compared with 7.18, 7 and 6.67 h for Cartafri, Rancho and Cartamar, respectively. Likewise, we established a positive correlation between the oxidative stability and c-tocopherol; however, this difference was not significant. [less ▲]

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See detailEvaluation of the oxidative stability of blends of ‘Arbequina’ olive oils with other monovarietal olive oils
Mansouri, F.; Ben Moumen, A.; Houmy, N. et al

in Olivae (Official Journal of the International Olive Council) (2014), 120

Like elsewhere in the Mediterranean, the olive oil sector is one of the strategic branches of the Moroccan economy owing to its social and economic significance. This research entailed evaluation of the ... [more ▼]

Like elsewhere in the Mediterranean, the olive oil sector is one of the strategic branches of the Moroccan economy owing to its social and economic significance. This research entailed evaluation of the oxidative stability of olive oils made up of a blend of ‘Arbequina’ olive oil with ‘Arbosana’ and ‘Koroneiki’ monovarietal oils known for their high content of natural antioxidants (phenols and tocopherols) and their superior oxidative stability compared with ‘Arbequina’ oil. The monovarietal oils produced from the ‘Arbequina’, ‘Arbosana’ and ‘Koroneiki’ varieties, which have recently been introduced under intensive cultivation in the eastern region of Morocco, underwent physico–chemical characterisation to determine quality criteria, natural antioxidant content, fatty acid composition and triacylglycerol profile. The Rancimat test* was performed to assess the oxidative stability of these monovarietal oils and their three-variety blends. The oxidation tests were performed on five freshly prepared blends (A) of the three varieties – ‘Arbequina’/’Arbosana’/‘Koroneiki’ – according to the following volume ratios: A1: 60/30/10; A2: 60/20/20; A3: 60:10:30; A4: 50:25:25 and A5: 40:30:30. The test results show that blends A4 and A5 displayed the best oxidative stability, recording respective values of 72.67 h and 75.42 h. These results are comparable to those obtained for ‘Arbosana’ monovarietal oil (75.42 h), which is considered to be relatively stable. Hence, blending is an excellent tool for enhancing oils produced from varieties which, despite their excellent initial quality and their organoleptic attributes, are handicapped by their poor stability, as is the case of ‘Arbequina’ oil. [less ▲]

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See detailUse of lipases for the kinetic resolution of lactic acid esters in heptane or in a solvent free system
Richard, Gaetan ULg; Nott, Katherine; Nicks, François et al

Poster (2014, February 07)

This poster illustrates the kinetic resolution of lactic acid esters using CAL-B as catalyst. The racemic mixture is resolved in heptane and even in a solvent free system.

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See detailEffect of sun-drying on flavonoïd composition and antioxidant activity of three dark fig varieties
Bachir Bey, M.; Richard, Gaetan ULg; Fauconnier, Marie-Laure ULg et al

Poster (2014, February 07)

The aim of the study was to investigate the effect of sun-drying on individual flavonoïd and antioxidant activities of three dark fig varieties (Azenjar, Bouankik, and Aberkane). Flavonoïd compounds were ... [more ▼]

The aim of the study was to investigate the effect of sun-drying on individual flavonoïd and antioxidant activities of three dark fig varieties (Azenjar, Bouankik, and Aberkane). Flavonoïd compounds were identified and quantified using high-performance liquid chromatography. The results showed that all samples significantly differed in their flavonoïd compositions. [less ▲]

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See detailTechnologie de production de masse d’insectes - INSECTECH
Richard, Gaetan ULg; Hance, Thierry; Fauconnier, Marie-Laure ULg et al

Report (2014)

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See detailTechnologie de production de masse d’insectes - INSECTECH
Richard, Gaetan ULg; Hance, Thierry; Fauconnier, Marie-Laure ULg et al

Report (2013)

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See detailUse of response surface methodology for the optimization of the lipase-catalyzed synthesis of mannosyl myristate in pure ionic liquid
Galonde, Nadine ULg; Brostaux, Yves ULg; Richard, Gaetan ULg et al

in Process Biochemistry (2013), 48(11), 1914-1920

The purpose of the present study is to find the conditions allowing to reach the highest 24 h-yield(24 h- ) for the synthesis of mannosyl myristate catalyzed by the immobilized lipase B from Candida ... [more ▼]

The purpose of the present study is to find the conditions allowing to reach the highest 24 h-yield(24 h- ) for the synthesis of mannosyl myristate catalyzed by the immobilized lipase B from Candida antarctica (Novozym®435) in the ionic liquid (IL) [Bmpyrr][TFO] (1-butyl-1-methylpyrrolidinium tri-fluoromethanesulfonate). A full factorial design (FFD) was used in order to study the influence of three variables (temperature, mannose/vinyl myristate ratio and total substrate quantity) on the 24 h- . This design led to a model based on a second order polynomial response function. The resulting predicted con-tour plots have shown that the highest 24 h- should be obtained with high temperatures, low sugar/vinylester molar ratio and intermediate total substrate quantities (mmol). The model has been successfully verified and experimentally confirmed at the optimal conditions of 80◦C, substrate molar ratio of 1/10and total substrate quantity of 0.26 mmol leading to the highest predicted 24 h- of 72.2%. [less ▲]

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See detailUse of lipases for the kinetic resolution of lactic acid esters in heptane or in a solvent free system
Richard, Gaetan ULg; Nott, Katherine ULg; Nicks, François et al

in Journal of Molecular Catalysis B : Enzymatic (2013), 97

tKinetic resolution of d,l-ethyl lactate (d,l-LA-Et) and d,l-butyl lactate (d,l-LA-Bu) was accomplished inthe presence of lipases. Transesterification of the lactate esters with alcohols was shown to be ... [more ▼]

tKinetic resolution of d,l-ethyl lactate (d,l-LA-Et) and d,l-butyl lactate (d,l-LA-Bu) was accomplished inthe presence of lipases. Transesterification of the lactate esters with alcohols was shown to be poorlyenantioselective, with a very low preference toward the l enantiomer. However, esterification of the freehydroxyl function of the lactate esters was much more enantioselective, with an opposite preferencetoward the d form. Among the 200 combinations screened (substrates and lipases), only two reactionsfulfilled the required criteria for an efficient resolution (fast reaction, enantioselectivity ratio higherthan 100). The best resolution was obtained by esterification of d,l-LA-Bu with butyric anhydride inthe presence of lipase B from Candida antarctica (CAL-B) in heptane (at 30◦C): LA-Bu was resolved in6 h with an initial esterification rate of d-LA-BU of 1.5 g L−1h−1g−1EZ, an enantioselectivity ratio higherthan 100, a l substrate consumption lower than 1%, and a final substrate enantiomeric excess superiorto 99%. After having demonstrated that neither LA-Bu nor BuAn were inhibitors of CAL-B, the reactionwas further improved by carrying it out in a solvent free system, at an elevated temperature (60◦C), andat a higher lipase concentration. LA-Bu was resolved in 6 h with an initial rate of 7.6 g L−1h−1g−1EZ, anenantioselectivity ratio higher than 100, and a final substrate enantiomeric excess of 95%. [less ▲]

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See detailAmphiphilic structure-surface property relationships of monosaccharide-based surfactants
Razafindralambo, Hary ULg; Nicks, Francois ULg; Richard, Gaetan ULg et al

Poster (2013, April 08)

A set of monosaccharide-based renewable surfactants has been prepared, structurally checked, and systematically screened for different activities and functionalities. These compounds vary in the polar ... [more ▼]

A set of monosaccharide-based renewable surfactants has been prepared, structurally checked, and systematically screened for different activities and functionalities. These compounds vary in the polar head group, linker, and hydrophobic tail. Beyond the goal to find out the most potential valuable surfactants for each measurement, relationships between chemical structure, basic properties, and functionalities have been examined by comparing compounds differing in a single structural variable. In this paper, we show and explain the impact of the anomeric alpha or bêta, neutral or acid sugar derivatives, equatorial or axial position of hydroxyl group, alkyl chain substitute attachment position, number, and length on surface properties of sugar-based surfactants. [less ▲]

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