Michel Parmentier

Enrichment of salmon oil with n-3 PUFA by lipolysis, filtration and enzymatic re-esterification

Selective enzymatic hydrolysis of salmon oil extracted without solvent from by-products was carried out under mild conditions, using a stereospecific sn-1, sn-3 lipase Novozyme®. A modification of the lipid class composition was obtained by controlling the degree of hydrolysis (40%, 24 h). The mixture of acylglycerols and free fatty acids was submitted to a filtration step to retain in the retentate most of the saturated fatty acids, with melting peaks ranging from -31.9 °C to +14.7 °C obtained by differential scanning calorimetry. This step allowed a significant increase of polyunsaturated fatty acids (PUFA) from 39.2 mol-% in the crude oil to 43.3% in the permeate. The remaining free fatty acids in the permeate (20.2 wt-%) was re-esterified with an immobilized 1, 3-specific lipase IM60. Acylglycerols synthesis reached 90% in optimized conditions. After 48 h of reaction, the distribution of monoacylglycerols, diacylglycerols and triacylglycerols was 22.1, 28.7, 43.4 (w/w), respectively. The re-esterification step did not modify the PUFA content obtained after membrane filtration.

Etude des conditions d’extraction de l’huile par pressage des amandes de Ricinodendron heudelotii (Bail.) Pierre ex Pax

Resume Les conditions d’extraction de l’huile par pressage des amandes de Ricinodendron heudelotii (Bail.) apres fragilisation ont ete realisees. La fragilisation des amandes est faite par voie humide et par voie seche a diverses temperatures (50, 70 et 90 °C) et a des temps de sejour variables (5, 10, 15, 20, 30 et 60 min). Les resultats montrent que le pretraitement a 90 °C pendant 60 min donne la plus grande friabilite aussi bien par voie seche que par voie humide soient 60,86% et 58,13% respectivement. Le chauffage et le broyage des amandes ameliorent de maniere significative (p

Filtration in hydrophobic media: 2. A triglyceride partition phenomenon as observed by tangential filtration of butter oil

Having demonstrated a partition of a hydrophobic medium (butter oil) under crossflow filtration and having tentatively explained the phenomenon on stereochemical and saturation basis, the molecular partition was studied by tangential filtration. Under specific hydrodynamic conditions, a filtration phenomenon was demonstrated. The solid fat content (SFC) at 20°C of the fractions obtained was investigated accordingly. When the molecular partition takes place, an SFC divergency between the permeate and the retentate is observed. The amplitude of the divergency depends on experimental conditions.

Heat treatment of cream: A model of the butter texture response in relation with triglyceride composition

The effects of thermal treatments on butter texture are known and have been used since 1935 on an industrial scale, but without fundamental knowledge. Butter composition influences firmness, as observed through seasonal and regional variations. Experiments were carried out at 15°C by using a cone penetrometer and an industrial testing machine. A significant correlation between heat treatment efficiency and some prevalent triglycerides and fatty acids on butter firmness was outlined. Three fatty acids (myristic, oleic, palmitic) and four major groups of triglycerides mainly affected the firmness, sometimes leading to an inversion of the thermal effect, according to individual sample composition. A crystallographic and thermodynamic model based on triglycerides properties was developed.

Molecular interaction of triglycerides on a modified silica (Kieselguhr G): a thermodynamical approach by surface tension calculation and DSC measurements

Peanut and linseed oils were drained vertically on thin layers, made of either native, hydrophilic or hydrophobic Kieselguhr G (silica), in order to get information on the interactions that may occur between triglycerides (TGs) and the filtering material. Except for hydrophobic silica, a partition of the TGs as function of the distance run was observed. Highly-unsaturated TGs were concentrated at the starting point of the running distance and distances between fractions grew larger with the hydrophobicity of the silica. Surface tension components of silica were calculated: whereas Van Oss method could not discriminate between hydrophilic and hydrophobic Kieselguhr G, Chibowskis method differentiated both compounds by a higher electron donor component (γ - ) in hydrophilic silica. Calorimetric studies of pure TGs interacting with Kieselguhr G discriminated between saturated TGs exhibiting a lower melting temperature as they interacted with the support, and unsaturated TG having a higher melting temperature. It is concluded that electron densities are involved in interactions occurring between TGs and silica, i.e. high unsaturation number and high γ - component. Des huiles darachide et de lin secoulent verticalement sur des couches minces constituees de silice (Kieselguhr G) hydrophile ou hydrophobe, afin dobtenir des informations sur les interactions entre les triglycerides (TG) et le substrat. A lexception de la silice hydrophobe, une partition des TG est observee en fonction de la distance ecoulee. Les TG hautement insatures sont concentres dans la zone de depart et les ecarts entre fractions augmentent avec lhydrophobicite de la silice. La calorimetrie DSC montre une plus faible temperature de fusion pour les TG satures que pour ceux insatures.

FATTY ACIDS AND TRIGLYCERIDES OF Canarium schweinfurtthii Engl. FRUIT

ABSTRACT The present paper reports data on the fatty acids of Canarium schweinfurtthii Engl, as well as triglyceride and unsaponifiable matter content of fruit pulp. This fruit is consumed as such or after cooking in hot water by some cameroonian populations. Qualitatively, the pulp, shell, membrane and kernel contain predominantly (more than 96%) the same seven fatty acids. However, the content of each fatty acid varies between the different parts. Pulp oil is mainly composed in decreasing order of palmitic, oleic and linoleic acids. Shell oil is rich in stearic acid (20%) and in addition contains non negligible amounts of lauric and myristic acids; the principal fatty acids are palmitic, oleic, stearic and linoleic acids. The principal fatty acids of membrane and kernel oils are oleic, linoleic and palmitic acids. Membrane oil contains a high proportion of linoleic acid whereas kernel has a greater percentage of oleic acid. Pulp oil contains 14 triglycerides of which 4 account for more than 70%, namely:...