Hydrocolloids as emulsifiers and emulsion stabilizers

Advances in the study of proteolysis during cheese ripening.

Food proteins: a review on their emulsifying properties using a structure-function approach.

Background
Copper oxide (CuO) nanoparticles have attracted huge attention due to catalytic, electric, optical, photonic, textile, nanofluid, and antibacterial activity depending on the size, shape, and neighboring medium. In the present paper, we synthesized CuO nanoparticles using gum karaya, a natural nontoxic hydrocolloid, by green technology and explored its potential antibacterial application.

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Green synthesis of copper oxide nanoparticles using gum karaya as a biotemplate and their antibacterial application.

The exploitation of protein–polysaccharide interactions offers opportunities for the design of new ingredients and interfacial structures with applications in the food and pharmaceutical industries. Association of protein and polysaccharide molecules may occur chemically through covalent bonds or physically through electrostatic interactions. Theoretical and experimental studies indicate that various molecular and thermodynamic factors can be adjusted to optimize the effectiveness of covalent conjugates and electrostatic complexes in the stabilization of interfaces, gels and emulsions. Maillard-type protein–polysaccharide conjugates have excellent emulsifying and steric stabilizing properties, especially under conditions where the protein alone is poorly soluble. Charged polysaccharides form soluble complexes or coacervates with proteins depending on pH, ionic strength, and biopolymer charge distribution. The structure and stabilizing properties of the mixed protein + polysaccharide layer depends on the sequence of adsorption of the biopolymers to the interface. There is good potential for use of interfacial protein–polysaccharide complexes in the nanoscale engineering of delivery vehicles for nutrient encapsulation and in the protection of adsorbed proteins and emulsified lipids against enzymatic breakdown during digestion.

Interfacial structure and stability of food emulsions as affected by protein–polysaccharide interactions

This paper presents a review of the industrially most relevant exudate gums: gum arabic, gum karya, and gum tragacanth. Exudate gums are obtained as the natural exudates of different tree species and exhibit unique properties in a wide variety of applications. This review covers the chemical structure, occurrence and production of the different gums. It also deals with the size and relative importance of the various players on the world market. Furthermore, it gives an overview of the main application fields of the different gums, both food and non-food.

Exudate gums: occurrence, production, and applications

Improved emulsion stabilizing properties of whey protein isolate by conjugation with pectins

In this project we report on the angiotensin I-converting enzyme (ACE)-inhibitory activity of a bovine gelatin hydrolysate (Bh2) that was submitted to further hydrolysis by different enzymes. The thermolysin hydrolysate (Bh2t) showed the highest in vitro ACE inhibitory activity, and interestingly a marked in vivo blood pressure-lowering effect was demonstrated in spontaneously hypertensive rats (SHR). In contrast, Bh2 showed no effect in SHR, confirming the need for the extra thermolysin hydrolysis. Hence, an angiotensin I-evoked contractile response in isolated rat aortic rings was inhibited by Bh2t, but not by Bh2, suggesting ACE inhibition as the underlying antihypertensive mechanism for Bh2t. Using mass spectrometry, seven small peptides, AG, AGP, VGP, PY, QY, DY and IY or LY or HO-PY were identified in Bh2t. As these peptides showed ACE inhibitory activity and were more prominent in Bh2t than in Bh2, the current data provide evidence that these contribute to the antihypertensive effect of Bh2t.

Angiotensin I-converting enzyme inhibitory activity of gelatin hydrolysates and identification of bioactive peptides.

Effects of sucrose and sorbitol on the gel formation of a whey protein isolate

Summary - Most of the classification methods so far published for chee se varieties which are based either on rheological or compositional properties appear to be inadequate. Still, a promising approach in this area of cheese research is the application to proteolytic patterns of multivariate statistics such as principal component analysis (PCA) and discriminant analysis (DA). Both techniques were therefore performed on electrophoretic profiles obtained by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SOS-PAGE) of the pH 4.6-insoluble protein fraction of cheese. Cheese sampI es of different Belgian varieties (Passendale, Wijnendale, Nazareth and Oud Brugge) with different grades of maturity were investigated and compared to other international brands. The SOS-PAGE method was performed by means of the PhastâystemfN. The method produces volumograms which allow not only qualitative but also quantitative interpretation. Generally it can be concluded that PCA resulted in a clear separation of Nazareth and Oud Brugge and to a lesser extent of Passendale and Wijnendale; DA allowed correct classification of the four Belgian cheeses, and comparison with international brands determined known similarities between the cheeses. This tool may therefore be of use in the field of authenticity research and classification. To a lesser extent, the method can also help in determining the maturity of a ripening cheese. cheese 1proteolysis 1classification 1SDS-PAGE 1 multivariate analysis

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Stephan Dierckx

Papers

Exudate gums: occurrence, production, and applications

Improved emulsion stabilizing properties of whey protein isolate by conjugation with pectins

Angiotensin I-converting enzyme inhibitory activity of gelatin hydrolysates and identification of bioactive peptides.

Effects of sucrose and sorbitol on the gel formation of a whey protein isolate

Comparison of SDS-PAGE profiles of four Belgian cheeses by multivariate statistics