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21.
Zphirin Mouloungui Sandrine Pelet 《European Journal of Lipid Science and Technology》2001,103(4):216-222
A series of glycerol carbonate esters derived from glycerol carbonate was synthesised by acylation of glycerol carbonate in the presence of aliphatic acyl chlorides. These compounds are characterised polyoxygenated by an endocyclic diester function and an exocyclic ester function. Physical and physicochemical properties of glycerol carbonate esters are determined. These compounds present a good thermal and oxidation stability. They exhibit surfactant properties towards water/soybean oil interface. The polyfunctional properties enable developments in existing industrial applications as well as in new niche markets. 相似文献
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23.
Bassam Nohra Laure Candy Jean-François Blanco Yann Raoul Zephirin Mouloungui 《Journal of the American Oil Chemists' Society》2012,89(6):1125-1133
Aminolysis reaction of glycerol carbonate with primary amine in organic and hydroorganic media leads to the formation of two hydroxyurethane isomers and a partial decomposition of glycerol carbonate into glycerol. Aminolysis with a secondary amine promotes the condensation reaction and limits the formation of glycerol. The ratio of α versus β was determined by zgig 13C NMR. This technique permits computing the yield of α and β products in the medium. The quantity of glycerol was determined by GC analysis. The ratio of the isomers and the amount of glycerol depend on the amine and the solvent. Kinetic investigations reveal that, in hydroorganic medium, the more the alkyl chain of the amine increased, the less glycerol was formed. On the contrary, in organic medium, the alkyl chain of the amine does not play a major role in the formation of glycerol. 相似文献
24.
Jane Roche Marion AlignanAndrée Bouniols Muriel CernyZephirin Mouloungui Othmane Merah 《Food chemistry》2010
Sunflower seeds are currently used for edible oil production. Among oil minor compounds, phytosterols are of special interest due to their cholesterol reducing properties. This paper reports studies on their accumulation and distribution in the embryo and hull, and the effects of temperature on phytosterol contents in sunflower seed produced under both conventional and organic field conditions. An optimised method of sterol determination, adapted to studies on small samples of seed, is presented. Seventy-two percent of phytosterols were found in the embryo, 28% in the hull. The periods of phytosterols concentration varied according to sterol category and seed part. Application of these results to improve production of natural sterols for functional food use is discussed. 相似文献
25.
Caroline Rondel Isabelle Alric Zéphirin Mouloungui Jean-François Blanco Françoise Silvestre 《Journal of surfactants and detergents》2009,12(3):269-275
The acylation of amino acids by acid chlorides with from 8 to 12 carbon atoms in alkaline aqueous medium following Schotten–Baumann reaction results in sodium salts of a N α-acylamino acid and fatty acid mixture. The latter are present in a proportion from 40 to 60%. These compositions represent mixtures of amphiphilic anionic surfactants. Together they contribute to the properties of the formulation. Measurements of the surface-active properties of these formulations, such as critical micelle concentration (CMC), surface tension at the CMC (ST), foaming capacity (FC) and foaming stability (FS), show that surfactant mixtures with the longest chain have the most desirable properties. They are comparable to commercial petroleum-based surfactants. Thus, the CMC, ST and CM values of the formulation obtained starting from leucine and dodecanoyl chloride (310 mg/l, 30.1 mN/m and 200%, respectively) are similar to, and even better than, sodium dodecylsulfate (290 mg/l, 39.1 mN/m and 230%, respectively). 相似文献
26.
Valérie Eychenne Zéphirin Mouloungui 《Journal of the American Oil Chemists' Society》1998,75(10):1437-1440
Esters of trimethylolpropane were prepared by reaction of trimethylolpropane with erucic acid. Unreacted erucic acid was eliminated
by fixation on an anion exchange resin to produce an oil with a low free fatty acid content. The authors describe the deacidification
of the reaction product by Lewatit MP500A and MP600 resins in a fixed-bed reactor or in a stirred reactor. The discontinuous
process gave the best results with the Lewatit MP600 resin in a stirred reactor with a 99% yield. The acid value was below
0.1 after less than 1 h of contact. 相似文献
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Corinne Dufaure Juliette Leyris Luc Rigal Zéphirin Mouloungui 《Journal of the American Oil Chemists' Society》1999,76(9):1073-1079
Lipids are traditionally removed from seeds by mechanical crushing and solvent extraction. During the mechanical crushing
process the oilseed is cleaned, cracked, flaked, and cooked before entering a mechanical screw press. Seventy-five percent
of the oil of sunflower seeds can be extracted by crushing, and the fatty cake then contains about 15% of oil. The oil levels
remaining in the cake can be reduced to less than 2% by solvent extraction. However, the crude oil has to be refined as it
contains many impurities and approximately 600 ppm phosphorus. A new process, in which sunflower seeds are pressed in a twin-screw
extruder, is examined here. The screw profile was first optimized. Oleic sunflower seeds were crushed and 80% of the oil was
removed. The resultant oil was of good quality, with acid numbers below 2 mg KOH/g of oil and total phosphorus contents of
about 100 ppm. The influence of pressing temperature and of fresh seed moisture content was determined. High pressing temperature
and low moisture content improved oil extraction. The quality of the meal was examined through the solubilization of its proteins
in alkaline water at 50°C. The fatty meal proteins remained quite soluble, and therefore one can assume that they were still
relatively close to their native conformation. The pressing of oleaginous material in a twin-screw extruder provides a new
option to traditional processes.
Presented as an oral communication at the 2nd American Oil Chemists’ Society Europe Symposium, October 1–4, 1998, at Cagliari,
Italy. 相似文献
29.
Divine Nde Bup Charles Fon Abi Gilles Bernard Nkouam Dzudie Tenin César Kapseu Clergé Tchiegang Zéphirin Mouloungui 《Food and Bioprocess Technology》2013,6(8):1897-1906
The standard static gravimetric method was used to determine moisture sorption isotherms of both raw and cooked sheanut kernels at 40, 50 and 60 °C in the water activity range 0.11–0.96 in order to evaluate the influence of cooking on the moisture sorption capacity of the kernels. Preliminary analysis showed that the kernels lost a significant quantity of its proteins and carbohydrate during the cooking process. Results of analysis of the moisture sorption isotherms revealed that cooked kernels generally had significantly (p?<?0.05) lower equilibrium moisture contents (EMC) than the raw ones for both desorption and adsorption processes. The effect of temperature on the sorption processes as portrayed by the desorption isotherms revealed that EMC decreased steadily with increase in temperature within the water activity range 0.10–0.8 aw but increased rapidly with increase in temperature above 0.8 aw resulting in the overlap of isotherms for all sorption processes. This crossing over of isotherms was attributed to the dissolution of sugars at higher water activities. The protein matrix in the kernel was observed using light microscopy and was found to have been disorientated after cooking. Studies using light and scanning electron microscopy revealed that the reduced ability of cooked kernels to sorb water could be linked to changes in the structure of the kernels brought about by the cooking of the kernels. It is concluded that cooking had a very significant effect on the amount of water sorbed by sheanut kernels. 相似文献
30.
Caroline Rondel Bénédicte Portet Isabelle Alric Zéphirin Mouloungui Jean-François Blanco Françoise Silvestre 《Journal of surfactants and detergents》2011,14(4):535-544
A pea protein isolate was hydrolyzed by a double enzyme treatment method in order to obtain short peptide sequences used as
raw materials to produce lipopeptides-based surfactants. Pea protein hydrolysates were prepared using the combination of Alcalase
and Flavourzyme. The influence of the process variables was studied to optimize the proteolytic degradation to high degrees
of hydrolysis. The average peptide chain lengths were obtained at 3–5 amino acid units after a hydrolysis of 30 min with the
mixture of enzymes. Then, N-acylation in water, in presence of acid chloride (C12 and C16), carried out with a conversion rate of amine functions of
90%, allowed to obtain anionic surfactant mixtures (lipopeptides and sodium fatty acids). These two steps were performed in
water, in continuous and did not generate any waste. This process was therefore in line with green chemistry principles. The
surface activities (CMC, foaming and emulsifying properties) of these mixtures were also studied. These formulations obtained
from natural renewable resources and the reactions done under environmental respect, could replace petrochemical based surfactants
for some applications,. 相似文献