Valorisation in bread of dietary fibres from by-products of the agro-industries.

Poster (2007, May)

L'évaluation sensorielle des aliments

Conference given outside the academic context (2007)

Le goût

Speech (2007)

Enrichment of anhydrous milk fat in polyunsatured fatty acid residues from linseed and rapeseed oil through enzymatic interesterification

Poster (2007)

The interesterification, or ester exchange, between two fats leads to the rearrangement of acyl moieties in both. The use of a sn-1,3-specific lipase confines the exchange of fatty acid residues to the sn ... [more ▼]

The interesterification, or ester exchange, between two fats leads to the rearrangement of acyl moieties in both. The use of a sn-1,3-specific lipase confines the exchange of fatty acid residues to the sn-1 and sn-3 positions of triacylglycerides (TAG), generating products with characteristics that cannot be obtained through a chemical process or a blending. Such reactions require mild conditions with no solvent needed and they yield no unhealthful trans fatty acids, justifying the stepped-up interest of enzymatic interesterification for the production of margarines and other food fats. The aim of this work was to use enzymatic interesterification to enrich anhydrous milk fat (AMF) with unsaturated fatty acid C18 residues from linseed oil (LO) and eventually from rapeseed oil (RO) through some binary blends and one ternary blend. For that, the 1,3-specific lipase from Thermomyces lanuginosa (Lipozyme TL IM) was used in solvent-free batch and micro-aqueous reactions and fat blends with different mass ratios were tested. The evolution of TAG profiles, of interesterification degre (ID) and of free fatty acids (FFA), was followed along the reactions. Determination of dropping points (DP) and solid fat contents (SFC) enabled a rheological characterization of the products. The end products were also characterized for their oxidative stability and their textural properties. [less ▲]

Chromatographic, Spectrometric and NMR Characterization of a New Set of Glucuronic Acid Esters Synthesized by Lipase

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2007), 11(1), 9-17

Nigella sativa L.: Chemical composition and physicochemical characteristics of lipid fraction

in Food Chemistry (2007), 101(2), 673-681

Physicochemical properties of two Nigella seed varieties, having a Tunisian and Iranian origin, were determined. Physical and chemical analyses of crude oils extracted from the seeds by a cold solvent ... [more ▼]

Physicochemical properties of two Nigella seed varieties, having a Tunisian and Iranian origin, were determined. Physical and chemical analyses of crude oils extracted from the seeds by a cold solvent method were also performed. The following results (on a dry-weight basis) were obtained for Tunisian and Iranian varieties, respectively: protein 26.7% and 22.6%, oil 28.48% and 40.35%, ash 4.86% and 4.41%, and total carbohydrate 40.0% and 32.7%. The major unsaturated fatty acids were linoleic acid (50.3-49.2%), followed by oleic acid (25.0 23.7%), while the main saturated fatty acid was palmitic acid (17.2-18.4%). Myristic, myristoleic, palmitoleic, margaric, margaroleic, stearic, linolenic, arachidic, eicosenoic, behenic and lignoceric acids were also detected. Thermal profiles of both Nigella seed varieties, determined by their DSC melting curves, revealed different thermograms. Sensorial profiles of Tunisian and Iranian seed oils were defined through the CieLab (L-*, a(*), b(*)) colour, oxidative stability by Rancimat test and viscosity. Physicochemical properties of the oils for Tunisian and Iranian varieties, respectively, include: saponification number 211 and 217, peroxide value 5.65 and 4.35, iodine index 120 and 101, and an acidity of 22.7% and 18.6%. Results suggested that Nigella seed oil could deserve further consideration and investigation as a potential new multi-purpose product for industrial, cosmetic and pharmaceutical uses. (c) 2006 Elsevier Ltd. All rights reserved. [less ▲]

Preparation and characterization of osmodehydrated fruits from lemon and date by-products

in Food Science & Technology International (2007), 13(6), 405-412

An osmotic dehydration process (ODP) was established in order to formulate osmodehydrated fruits from lemon and date by-products. ODP was conducted at 40 degrees C, maintained using an oven, or a water ... [more ▼]

An osmotic dehydration process (ODP) was established in order to formulate osmodehydrated fruits from lemon and date by-products. ODP was conducted at 40 degrees C, maintained using an oven, or a water bath with continuous stirring. The kinetics of the osmodehydration in a water bath showed a better mass transfer. Then, osmodehydrated fruit (ODF) preparations of about 40 degrees Brix were formulated using different isotonic solutions (sucrose, glucose/sucrose, glucose, and date juice). All the formulated products showed better characteristics (lower acidity, higher sugar content, etc.) than the untreated lemon by-product. The isotonic solution composition influenced their physical characteristics such as microstructure and viscosity. In fact, ODF prepared in glucose and glucose/sucrose solutions presented more open structures, lower viscosities, and water holding capacities (WHC) than the others. The products were microbiologically stable during 3 months at 4 degrees C. These results support the valorization of lemon and date by-products as ODF that could be consumed or incorporated as an ingredient in food formulations. [less ▲]

Isolation and identification of inulooligosaccharides resulting from inulin hydrolysis

in Analytica Chimica Acta (2007), 604(1), 81-87

In this study, inulooligosaccharides (F-n-type inulin) resulting from the endo-inulinase hydrolysis of globe artichoke inulin were purified and characterized. The aim was to produce F-n oligomer standards ... [more ▼]

In this study, inulooligosaccharides (F-n-type inulin) resulting from the endo-inulinase hydrolysis of globe artichoke inulin were purified and characterized. The aim was to produce F-n oligomer standards with the intention of identifying them in the complex inulin chromatogram. Inulin was extracted from globe artichoke and presented a high average degree of polymerization (DP) of about 80 as determined by high-performance anion exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD). This inulin was hydrolyzed by a commercial endo-inulinase yielding a product with a very high F-n/GF(n), molecule ratio, thus limiting the interference of GF(n) during the purification process. High performance size exclusion chromatography was used to individually isolate and collect each retention peak corresponding to a specific oligomer. The purity of these fractions was checked by HPAEC-PAD and showed that relatively pure molecules were produced. Electrospray ionization mass spectrometry allowed the molecular weight determination of these purified oligomers and ascertained their DP as F-2, F-3 and F-4. These F2-4 standards were used with glucose, fructose, sucrose and GF(2-4) (commercially available) to spike commercial oligofructose products in order to determine the elution profile in the HPAEC-PAD chromatogram. [less ▲]

On the understanding of the physical changes in inulin powder as a function of water activity.

Poster (2006, December)

Contribution technologique à l'élaboration de produits alimentaires "trans-free". Comportement thermique de mélanges binaires.

Poster (2006, November 17)