Impact of the Crystallinity on the Physical Properties of Inulin during Water Sorption

in Food Biophysics (2009), 4(1), 49-58

The impact of the crystallinity of spray-dried inulins on their stability and physical properties was investigated after a conditioning of 1 week at different relative humidity levels (0% to 94%) at 20 A ... [more ▼]

The impact of the crystallinity of spray-dried inulins on their stability and physical properties was investigated after a conditioning of 1 week at different relative humidity levels (0% to 94%) at 20 A degrees C. An environmental scanning electron microscopy study showed that the amorphous powders hardened at a relative humidity storage between 59% and 75%; while their semi-crystalline counterparts were partially agglomerated but friable in the same conditions. Caking was observed when the glass transition temperature of the amorphous phase of the material dropped below the storage temperature of the powder. It resulted in a crystallization of the structural units of varying lengths composing inulin, but also an increase of the crystallinity of the semi-crystalline ones. This study showed the importance of the crystallinity of inulin on its stability and physical properties during storage which is of crucial importance for the shelf-life of food and pharmaceutical products in the dry state. [less ▲]

Optimization of enzymatic extraction of ferulic acid from wheat bran, using response surface methodology, and characterization of the resulting fractions

in Journal of the Science of Food and Agriculture (2009), 89(10), 1634-1641

BACKGROUND: The agro-industries generate thousands of tons of by-products, such as bran or pulps, each year. They are, at best, used for cattle feeding. Through biocracking, this biomass may constitute a ... [more ▼]

BACKGROUND: The agro-industries generate thousands of tons of by-products, such as bran or pulps, each year. They are, at best, used for cattle feeding. Through biocracking, this biomass may constitute a renewable source for various molecules of interest for the industry. For instance, ferulic acid, a compound showing antioxidant ability, is found in abundance in cereal bran. Its release depends mainly on the breaking of its ester linkage to other constitutive elements of the cell wall, such as arabinoxylans. Response surface methodology was used to evaluate the effects of ferulic acid esterase (FAE) and xylanase activities, as well as incubation time and temperature, on ferulic acid extraction yield from wheat bran. Under optimized conditions, the composition of the hydrolysate and of residual bran were compared to native bran. RESULTS: Experiments carried out under the predicted optimal conditions (FAE amount, 27 U g(-1); xylanase amount, 304 U g(-1); incubation time, 2 h; and temperature, 65 degrees C) led to an extraction yield of 52.8%, agreeing with the expected value (51.0%). The crude ferulic acid fraction was purified with Amberlite XAD16, leading to a final concentration of 125 mu g mL(-1) of ferulic acid in ethanol. The antioxidant capacity of this purified fraction was evaluated by the DPPH. scavenging method: it exhibited better efficiency (EC50 = 10.6 mu mol L-1 in ferulic acid) than the ferulic acid standard (EC50 = 13.7 mu mol L-1). CONCLUSION: These results confirm the potential of wheat bran valorization in the field of natural antioxidant extraction, possibly viable in an industrial scheme. (C) 2009 Society of Chemical Industry [less ▲]

Effect of Cholesterol and Fatty Acids on the Molecular Interactions of Fengycin with Stratum Corneum Mimicking Lipid Monolayers.

in Langmuir : the ACS journal of surfaces and colloids (2009), 25

Influence Of Environmental Conditions On The Interfacial Organisation Of Fengycin, A Bioactive Lipopeptide Produced By Bacillus Subtilis

in Journal of Colloid and Interface Science (2009), 329(2),

Impacts of the carbonyl group location of ester bond on interfacial properties of sugar-based surfactants: experimental and computational evidences

in Journal of Physical Chemistry B (2009), 113

Interfacial properties of surfactants are dependent on the conformation adopted by the hydrophilic headgroup or/and the hydrophobic tail at the boundary limit of two immiscible phases. Here, we ... [more ▼]

Interfacial properties of surfactants are dependent on the conformation adopted by the hydrophilic headgroup or/and the hydrophobic tail at the boundary limit of two immiscible phases. Here, we demonstrate the impacts of the carbonyl group (-CO-) location of the ester bond of sugar-based surfactants by comparing some properties of two closely related esters, octyl glucuronate and glucose octanoate, at the air-water interface. The carbonyl group location influences the rate and extent of interfacial adsorption and the rheology properties of sugar esters at the air-water interface, which were evaluated by dynamic surface tension and complex surface viscoelastic measurements. Octyl glucuronate adsorbs the fastest at the air-water interface whereas glucose octanoate reduces the dynamic surface tension at the lowest value and exhibits the highest film viscoelasticity. Differences are attributed to molecular conformation constraints inducing relevant changes to the surface coverage kinetic capacity and the interaction strengths of the octyl sugar ester adsorbed films at the air-water interface. All of the results are supported by the minimum cross-sectional area values per molecule determined by both experimental and computational approaches. [less ▲]

Les produits lignocellulosiques comme source de biocarburants de deuxième génération dans un concept de bioraffinage

Conference given outside the academic context (2008)

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

Poster (2008, July)

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

Poster (2008, July)

Application of Isothermal Titration Calorimetry to Thermodynamic Studies of Surfactin Binding Interactions to Lipid Vesicles

Poster (2008, May 24)

Application of a chemoselective ligation strategy to the M1 factor of virginiamycin

Poster (2008, March 26)