Effect of water content and temperature on Carica papaya

Temperature and water activity (a w) of the reaction medium are two factors that govern enzyme reactions. We studied the influence of these two parameters on the esterification and transesterification activity of Carica papaya lipase in water and solvent free reactions. It was found that over the course of reaction the catalytic activity of C. papaya lipase was dependent on these factors. The best lipase activity for both reactions was at a temperature of 55°C and water activity of 0.22, which corresponds to 2 g of water per 100 g of C. papaya latex

Selection of CalB immobilization method to be used in continuous oil transesterification: Analysis of the economical impact

Enzymatic transesterification of triglycerides in a continuous way is always a great challenge with a large field of applications for biodiesel, bio-lubricant, bio-surfactant, etc. productions. The lipase B from Candida antarctica (CalB) is the most appreciated enzyme because of its high activity and its non-regio-selectivity toward positions of fatty acid residues on glycerol backbone of triglycerides. Nevertheless, in the field of heterogeneous catalysis, we demonstrated that the medium hydrophilic nature of the support used for its commercial form (Lewatit VPOC1600) is a limitation. Glycerol is adsorbed onto support inducing drastic decrease in enzyme activity. Glycerol would form a hydrophilic layer around the enzyme resulting in diffusional limitations during triglyceride transfer to the enzyme. Accurel MP, a very hydrophobic macroporous polymer of propylene, was found not to adsorb glycerol. Immobilization conditions using this support were optimized. The best support was Accurel MP1001 (particle size<1000μm) and a pre-treatment of the support with acetone instead of ethanol enables the adsorption rate and the immobilized enzyme quantity to be maximized. An economical approach (maximization of the process net present value) was expanded in order to explore the impact of immobilization on development of an industrial packed bed reactor. The crucial ratio between the quantity of lipase and the quantity of support, taking into account enzyme, support and equipped packed bed reactor costs was optimized in this sense. The biocatalyst cost was found as largely the main cost centre (2–10 times higher than the investments for the reactor vessel). In consequence, optimal conditions for immobilization were a compromise between this immobilization yield (90% of lipase immobilized), biocatalyst activity, reactor volume and total investments

Recettes de macérâts huileux : intérêt pour la cosmétique

The maceration is a particular contact process between virgin oil (as a solvent) and seeds, leaves or plant extracts (as a solid). This process enables the extraction of liposoluble content of the solid by ordinary pressure, using the virgin oil as a natural solvent. Moreover, it allows the extraction of liposoluble materials which are hardly extractable by simple pressure. In this review, traditional macerates and their cosmetic uses are reported

Mise au point sur l’analyse de la régiodistribution en acides gras des triacylglycérols

Dans la première partie de cette mise au point sont examinées les deux méthodes usuelles (enzymatique et chimique) pour l’analyse de la régiodistribution en acides gras des triacylglycérols. Le but est notamment de montrer les limites de leurs applications ainsi que les problèmes posés par la mise en œuvre des modes opératoires. Dans la deuxième partie de cet exposé, une nouvelle méthode d’analyse de la régiodistribution à partir des α‐monoacylglycérols obtenus par dégradation des triacylglycérols avec un réactif de Grignard est examinée à la lumière des résultats d’une étude théorique faite sur un triacylglycérol modèle

Recettes de macérâts huileux : intérêt pour la cosmétique

The maceration is a particular contact process between virgin oil (as a solvent) and seeds, leaves or plant extracts (as a solid). This process enables the extraction of liposoluble content of the solid by ordinary pressure, using the virgin oil as a natural solvent. Moreover, it allows the extraction of liposoluble materials which are hardly extractable by simple pressure. In this review, traditional macerates and their cosmetic uses are reported

Amélioration de la qualité nutritionnelle des huiles de poissons

Il a été démontré ces dernières années que les deux acides gras essentiels eicosapentaénoïque (EPA) et docosahexaénoïque (DHA), ont des propriétés physiologiques intéressantes chez l’homme. Ces effets bénéfiques ont accru l’intérêt de pouvoir disposer de préparations « ciblées », c’est-à-dire enrichies soit en EPA soit en DHA, les premières visant des applications en prophylaxie des maladies cardiovasculaires, les secondes visant à compléter l’alimentation de sujets risquant de présenter un déficit (prématurité et sénescence). Dans cette mise au point sur le biofaçonnement des huiles de poissons, nous nous attacherons à comprendre les avantages et les limites des méthodes mises en œuvre pour différencier l’EPA du DHA des huiles de poissons

Amélioration de la qualité nutritionnelle des huiles de poissons

BERTIN, route de Mareuil, BP 51,60330 Lagny-le-SecInternational audienceDuring the last few years, the physiological properties of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids have been investigated and beneficial effects can be attributed. EPA has been associated with a reduced risk of cardiovascular disease in adult, by altering platelet function towards a more anti‐atherogenic state. DHA is a major constituent of the neuronal structures including retina cell membranes. For populations at high risk of deficiency like new‐born babies and the elderly, diet must be supplemented with DHA. Therefore, these beneficial effects have promoted the development of dedicated preparations enriched either with EPA or DHA as long as bioavailability is needed in our diet. In this survey, the enzymatic methods to discriminate between EPA and DHA are reviewed.Il a été démontré ces dernières années que les deux acides gras essentiels eicosapentaénoïque (EPA) et docosahexaénoïque (DHA), ont des propriétés physiologiques intéressantes chez l’homme. Ces effets bénéfiques ont accru l’intérêt de pouvoir disposer de préparations « ciblées », c’est‐à‐dire enrichies soit en EPA soit en DHA, les premières visant des applications en prophylaxie des maladies cardiovasculaires, les secondes visant à compléter l’alimentation de sujets risquant de présenter un déficit (prématurité et sénescence). Dans cette mise au point sur le biofaçonnement des huiles de poissons, nous nous attacherons à comprendre les avantages et les limites des méthodes mises en œuvre pour différencier l’EPA du DHA des huiles de poissons