Enzymatic synthesis of fructose fatty acid esters : kinetics, purification and surface active properties characteization
This work aims to study kinetics, purification and surfactive properties of sugar esters obtained by enzymatic synthesis. Fructose and various fatty acids (C8 to C18) were used as substrates. These syntheses were carried out in methyl-2 butanol-2, at 60°C and in the presence of an immobilized Candid...
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| Other Authors: | , , |
| Format: | Doctoral or Postdoctoral Thesis |
| Language: | French |
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HAL CCSD
2001
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| Subjects: | |
| Online Access: | https://hal.univ-lorraine.fr/tel-01749881 https://hal.univ-lorraine.fr/tel-01749881/document https://hal.univ-lorraine.fr/tel-01749881/file/INPL_T_2001_SOULTANI_S.pdf |
| Summary: | This work aims to study kinetics, purification and surfactive properties of sugar esters obtained by enzymatic synthesis. Fructose and various fatty acids (C8 to C18) were used as substrates. These syntheses were carried out in methyl-2 butanol-2, at 60°C and in the presence of an immobilized Candida antarctica lipase as biocatalyst. From the kinetic point of view, the results obtained show that the activity of this enzyme is influenced by substrate concentrations, hydrophobicity and the level of water in the medium. By a judicious control of the synthesis environment, it was possible to convert the quasi totality of the substrates (>90 %) with concentrations bordering the 140 g/1. The monoesters/diesters selectivity was affected by the macro-environment of the system. The purification of the monoesters from the residual substrates was carried out successfully by a liquid-liquid extraction. The purity of the obtained products is about 99 % with losses less than 7%. These extractions were carried out on three sugaresters (C1O, C14 and C18). The characterization of the properties of the sugaresters in a pure state or in mixture with diesters showed that these molecules are as efficient as sucrose esters . They allow to stabilize H/E emulsions and to lower rapeseed oil/water interfacial tensions. In the same way, they have a high foaming capacity. Ce travail a pour objectif d'étudier la cinétique, la purification et les propriétés tensioactives de sucroesters obtenus par synthèse enzymatique. Le fructose et différents acides gras de C8 à C18 ont été utilisés comme substrats. Ces synthèses ont été réalisées dans le méthyl-2 butanol-2 à 60°C et en présence de la lipase de Candida antarctica immobilisée comme biocatalyseur. Du point de vue cinétique, les résultats obtenus montrent que l'activité de cette enzyme est influencée par les concentrations des substrats, l'hydrophobicité et le niveau de l'eau dans le milieu réactionnel. Par un contrôle judicieux de l'environnement de la synthèse, il a été possible de ... |
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