Interesterification of rapeseed oil with anhydrous milk fat and its stearin fraction. II. Modifications of melting properties

in Groupement Consultatif International de Recherche sur le Colza (2009), 25

Chemical and/or physical modification of oils and fats are commonly used by food industry to widen their range of applications (1,2). Lipase-catalysed interesterification of anhydrous milk fat (AMF) and ... [more ▼]

Chemical and/or physical modification of oils and fats are commonly used by food industry to widen their range of applications (1,2). Lipase-catalysed interesterification of anhydrous milk fat (AMF) and various vegetable oils is now a well documented procedure (3-7). The purpose of this technique is to produce original structured fats with properties different from a simple blending, that may be used as spreads or introduced into pastry. The new fats contain higher amounts of polyunsaturated fatty acids (PUFA) than butter, which provides health benefits (8,9). To our knowledge only a few authors associated AMF fractionation with blending and interesterification (10,11), although this combination may be used to increase the ratio of vegetable oil in blends and thus the PUFA content of the product. The compositional changes occurring during the lipase-catalysed interesterification of AMF/rapeseed oil (RO) and AMF stearin fraction (AMFSF)/RO blends were described in the first part of this study. In the present and second part are reported the resulting changes in physical properties, especially the melting behaviour through solid fat content (SFC), dropping point (DP) and fusion profiles by differential scanning calorimetry (DSC). [less ▲]

Effect of water uptake on amorphous inulin properties

in Food Hydrocolloids (2009), 23(3), 922-927

Physical property changes of amorphous spray-dried inulin were investigated during water uptake at 20 degrees C. Modulated Differential Scanning Calorimetry (MDSC) and Wide Angle X-ray Scattering (WAXS ... [more ▼]

Physical property changes of amorphous spray-dried inulin were investigated during water uptake at 20 degrees C. Modulated Differential Scanning Calorimetry (MDSC) and Wide Angle X-ray Scattering (WAXS) were used to investigate the evolution of the glass transition temperature (T-g) and the crystallinity index, respectively. The water content, crystallization and thermal properties relationship enabled the identification of three zones in the T-g-water content state diagram. Zone I delimited inulin in a glassy amorphous state, while zone II characterized inulin in a liquid amorphous state. Inulin crystallized and caked when T-g was below the storage temperature of 20 degrees C, but crystallization (zone III) was not spontaneous and was delayed by the defined zone II. The crystallization led to thermograms with an endotherm close to T-g. Temperature-Resolved WAXS allowed to correctly ascertain the MDSC endothermic peak as a melting peak because the crystallinity index was maximal at onset temperature of the transition, and dropped to zero at the endset temperature. (C) 2008 Elsevier Ltd. All rights reserved. [less ▲]

Compositional, Physical, Antioxidant and Sensory Characteristics of Novel Syrup from Date Palm (Phoenix dactylifera L.)

in Food Science & Technology International (2009), 15(6), 583-590

This study is a contribution to valorise date palm sap (Phoenix dactylifera L.) by elaboration of high quality syrup. Sap was concentrated by evaporation and the obtained product was characterized by its ... [more ▼]

This study is a contribution to valorise date palm sap (Phoenix dactylifera L.) by elaboration of high quality syrup. Sap was concentrated by evaporation and the obtained product was characterized by its physicochemical, rheological, thermal, sensory properties and by its antioxidant activity. Syrups from date palm sap have a good nutritional value marked by high amounts of sugars (58-75 g/100 g fresh matter basis), minerals (2.1-2.6 g/100 g fresh matter basis) and phenolics (147.61-224.55 mg of ferulic acid equivalents/kg fresh weight). Syrup also presents an antioxidant activity that appears related to total phenolic content. Rheological properties indicate that syrup preserves a Newtonian behavior from 10 degrees C to 55 degrees C well modeled by Arrhenius equation. Hedonic evaluation showed that consumers' appreciation of date palm syrup was not significantly different to the most known sap syrup: maple syrup. [less ▲]

Calorimetric study of milk fat/rapeseed oil blends and their interesterification products

in European Journal of Lipid Science and Technology [=EJLST] (2009), 111(4), 376-385

Milk fat (MF) and rapeseed oil (RO) blends were analyzed by differential scanning calorimetry (DSC). It was shown that peak and onset temperatures can be used to determine the percentage of each fat in ... [more ▼]

Milk fat (MF) and rapeseed oil (RO) blends were analyzed by differential scanning calorimetry (DSC). It was shown that peak and onset temperatures can be used to determine the percentage of each fat in the blend and that the relative enthalpy of one peak assigned to low-melting triacylglycerols (TAG) can also be used to determine the percentage of RO in the blend. A linear relation was also established between IMF content of the blend and its dropping point (DP), indicating that DP can be linearly related with the above DSC data. A blend of MF/RO 70 : 30 (wt/wt) was then chosen as a model system for enzymatic interesterification (EIE). The applicability of DSC analyses to EIE products was checked and a correct correlation could be established between DSC values and the interesterification degree and DP. Among the data from the DSC profiles, the peak associated with low-melting TAG was the best indicator of the reaction course. In the same way, a high-melting MF stearin fraction was interesterified. with RO. In that case, onset temperatures and peak "a" were better reaction indicators than for the interesterified MF/RO blend. We therefore suggest that values from DSC endotherms could be used to monitor EIE of fat blends. [less ▲]

High-throughput methodology applied to screening of carbohydrate-based surfactant interfacial properties for colloidal system formulations

Poster (2009)

Carbohydrate-based surfactants (CBS) constitute an attractive class of amphiphilic molecules owing to their structural diversity generating a wide range of properties which could be developed in food and ... [more ▼]

Carbohydrate-based surfactants (CBS) constitute an attractive class of amphiphilic molecules owing to their structural diversity generating a wide range of properties which could be developed in food and non-food applications. Based on many functional groups of the carbohydrate part, it is possible to design multiple amphiphilic structures of CBS varying in the hydrophilic head groups (mono-, oligo-, or polysaccharides), hydrophobic tail (mono-, di-, tricatenar) but also in the linker/spacer between them. The main structures of CBS include mono- and bicatenar glycolipids, bolaforms, and gemini. Moreover, CBS compounds can be produced from the most abundant renewable materials allowing large product concept possibilities. Among general properties of surfactants, interfacial properties molecules occupy a fundamental key role for colloidal system formulations since they control most of technological aptitudes required for forming and stabilizing food, cosmetic, agrochemical, detergent, and pharmaceutical products. High-throughput methodology applied to screening of CBS interfacial properties appears crucial for achieving optimum formulations of colloidal systems like foams and emulsions for which small amounts of single or mix surface-active agents are often needed and numerous physical and chemical parameters are involved. This general approach may be applied to any amphiphilic molecules produced from other renewable resources of surface-active compounds like micro-organisms and by direct extraction from vegetable materials. One of the key factors for the development of this methodology is the use of automated instrument systems in laboratory scale which are still lacking in this field compared to those existing in the analytical chemistry and biochemistry areas. [less ▲]

Osmotic dehydration of pomegranate seeds : mass transfert kinetics and differential scanning calorimetry characterization.

in International Journal of Food Science & Technology (2009), 44

Impact of physical properties of inulin on stability during moisture sorption.

Poster (2008, July)

Study of the stability and the physical property changes of amorphous inulin during moisture adsorption

Poster (2008, July)

Impact of pre-treatment processing on cereal by-products valorisation through enzymatic extraction of ferulic acid.

Poster (2008, June)

Approche sensorielle de la texture des aliments

Conference given outside the academic context (2008)