Study of surface and techno-functional properties of proteose peptone fractions

The total proteose-peptone fractions are complex heterogeneous mixture of thermoresistant proteins of whey. The general objective of this work was to contribute to a better knowledge and understanding of surface properties and techno-functional properties (foaming and emulsifying properties) and well as setting a relationship between the different properties. In this work, PPT fractions were extracted according to a classical approach and other industrially transposable by considering respectively the skimmed UHT milk and whey protein concentrate (WPC) as raw materials. The using of such both sources allowed to highlight the fundamental differences in the composition of the extracts of PPT. This has begotten a direct impact on the surfactant properties of the PPT. It has been therefore established that these differences at interfaces can have major consequences on their techno-functional behavior. This study also made it possible to determine the contribution of components especially non-hydrophobic and hydrophobic fractions in the interfacial behavior of PPT and the influence of pH, protein concentration, source and method of extraction. The setting in relationship of properties showed the existence of some statistically significant correlations between the interfacial parameters and, foaming and emulsifying properties. It will be therefore possible to predict the behavior of techno-functional PPT from some physico-chemical parameters. Finally, this study also showed that PPT fractions can be used as techno-functional agents in various food formulations based foams or emulsions

Interfacial activities of milk total proteose-peptone: contribution and miscibility of nonhydrophobic and hydrophobic fractions

Surface properties of a nonhydrophobic fraction of proteose-peptone (NHFPP) and a hydrophobic fraction of proteose-peptone (HFPP), obtained by hydrophobic-interaction chromatography, were investigated. Adsorption of NHFPP and HFPP on the surface activity of total proteose-peptone (TPP) followed a competitive mechanism, especially during the penetration phase and molecular rearrangements. Compression of mixed monolayers was used to study the miscibility of NHFPP and HFPP within TPP films. When NHFPP was mixed with HFPP, in a TPP film, both fractions were immiscible at the beginning of adsorption; they only became miscible when the polypeptide chains had moved from the surface to the aqueous phase, thus allowing a better organisation of proteins. The equation of excess free energy of compression was used to determine the interactions of NHFPP-HFPP within the TPP film through the mixed monolayer (thermodynamic properties); interactions between NHFPP and HFPP appeared less important than those that occurred between molecules within each fraction

Évolution des connaissances sur les fonctionnalités de la fraction protéose-peptone du lait: Propriétés techno-fonctionnelles et biologiques (synthèse bibliographique)

The total proteose-peptone fraction (TPP) is defined as a heat-stable soluble fraction of milk, representing about 10% of the whey protein. TPP is divided into two classes according to its origin. The first class consists of proteolysis fragments of the β-casein from the N-terminal region. These are non-hydrophobic fractions, which are the highly soluble β-CN-5P (f1-105/107); β-CN-4P (f1-28) and β-CN-1P (f29-105/107) respectively called PP5 (14.3 kDa), PP8S (9.9 kDa), and PP8F (4 kDa). The second class includes the hydrophobic fractions of glycoproteins, whose major constituents are a glycoprotein LP28, the highly hydrophobic glycoprotein LP18 and a hydrophobic peptide with apparent Mr, respectively 28 kDa, 18 kDa and 11 kDa. TPP has numerous interesting characteristics such as techno-functional properties (emulsifying and foaming actions) and biological properties (lipolysis inhibition and antimicrobial activities), making TPP usable as a potential functional ingredient for industry. In addition, these functional properties are partly governed by the major components including glycoproteins, such as LP28, due to their hydrophobic nature

Adsorption kinetics of total proteose peptone fractions at the air-water and n-dodecane-water interface

Surface properties of whey proteins are essential in applications requiring oil emulsification in an aqueous phase, or foam structure formation [1]. The adsorption at interfaces constitutes then an approach of the physico-chemical mechanisms of foaming and emulsifying properties. Proteose-peptone is the minor fraction of whey's protein, thermoresistant and acid-soluble protein fraction extracted from milk [2], and known for its interesting surface properties [3]. In this study, the TPP fractions were extracted from skimmed milk UHT (milk TPP) and whey protein concentrate (WPC TPP). Their adsorption kinetics at the air-water and n-dodecane-water interfaces was investigated by the drop volume tensiometer method. Protein solutions of 1% (w/v) were characterized under dynamic condition at various pH (4.0; native pH 4.67- 4.70 and 7.0). Milk TPP showed the lowest values as well as a faster reduction in surface tension at both considered interfaces. Therefore, TPP were found to e effective as surfactants. These results let us to presage good emulsifying and foaming properties of milk TPP compared to WPC TPP. The considerable influence of pH and extraction source on proteose-peptone's interfacial property have been highlighted

Les crèmes végétales : une alternative aux crèmes laitières

peer reviewe

Determination of the quality of smoked sea herring (Sardinella maderensis) produced by three smoking processes practiced in Ivory Coast

International audienc

Impact of defatting methods on the physicochemical and functional properties of white lupin protein isolates

International audienc

Impact of pulsed electric field treatment on the viability of Tenebrio molitor insect biomass, and on the following pressing and drying processes

International audienc

Development of 2D and 3D front face fluorescence spectroscopy for monitoring ultrasound treatment in the removal of pesticides residues from fresh lettuces at the laboratory and pilot scales

International audienc

Impact of pilot-scale microfluidization on soybean protein structure in powder and solution

peer reviewedThe effect of microfluidization treatment on the primary, secondary, and tertiary structure of soybean protein isolate (SPI) was investigated. The samples were treated with and without controlling the temperature and circulated in the system 1, 3, and 5 times at high pressure (137 MPa). Then, the treated samples were freeze-dried and reconstituted in water to check the impact of the microfluidization on two different states: powder and solution. Regarding the primary structure, the SDS-PAGE analysis under reducing conditions showed that the protein bands remained unchanged when exposed to microfluidization treatment. When the temperature was controlled for the samples in their powder state, a significant decrease in the quantities of β-sheet and random coil and a slight reduction in α-helix content was noticed. The observed decrease in β-sheet and the increase in β-turns in treated samples indicated that microfluidization may lead to protein unfolding, opening the hydrophobic regions. Additionally, a lower amount of α-helix suggests a higher protein flexibility. After reconstitution in water, a significant difference was observed only in α-helix, β-sheet and β-turn. Related to the tertiary structure, microfluidization increases the surface hydrophobicity. Among all the conditions tested, the samples where the temperature is controlled seem the most suitable