Polysaccharides interfacial property

Perez, A. A., Sanchez, C. C., Rodriguez Patino, J. M., Rubiolo, A. C., Santiago, L. G. (2012). Foaming characteristics of P-lactoglobulin as affected by enzymatic hydrolysis and polysaccharide addition Relationships with the bulk and interfacial properties. Journal of... 

Stevens, C. V., Meriggi, A., Peristerpoulou, M. et al. (2001) Polymeric surfactants based on inulin, a polysaccharide extracted from chicory. 1. Synthesis and interfacial properties. Biomacromolecules, 2 (4), 1256-1259. 

Complex polysaccharide/protein are very common in nature and are key ingredients in food systems stability [15, 29]. The combination of both offers a wide variety of novel applications, mostly as controlled delivery systems of active ingredients, used in various industries such as food, pharmaceuticals, and cosmetics [47, 80], Furthermore, there is great interest in the use of these systems because of the synergy that occurs when combining the two molecules, and generating new properties as stabilizers of emulsions and foams [9, 33, 87], showing better interfacial properties of hydration and absorption [107]. 

Protein-polysaccharide complexation affects the surface viscoelastic properties of the protein interfacial layer. Surface shear rheology is especially sensitive to the strength of the interfacial protein-polysaccharide interactions. Experimental data on BSA+ dextran sulfate (Dickinson and Galazka, 1992), asi-casein + high-methoxy pectin (Dickinson et al., 1998), p-lactoglobulin + low-methoxy pectin (Ganzevles et al., 2006), and p-lactoglobulin + acacia gum (Schmitt et al., 2005) have all demon-... 

Interfacial phenomena with special reference to biological systems. Chapter discussions include properties of proteins, polar lipids and polysaccharide at interfaces. A variety of spectrophotometric methods to resolve interfacial membrane structures are described in detail. 

Interactions between proteins and polysaccharides give rise to various textures in food. Protein-stabilized emulsions can be made more stable by the addition of a polysaccharide. A complex of whey protein isolate and carboxymethylcellulose was found to possess superior emulsifying properties compared to those of the protein alone (Girard et al., 2002). The structure of emulsion interfaces formed by complexes of proteins and carbohydrates can be manipulated by the conditions of the preparation. The sequence of the addition of the biopolymers can alter the interfacial composition of emulsions. The ability to alter interfacial structure of emulsions is a lever which can be used to tailor the delivery of food components and nutrients (Dickinson, 2008). Polysaccharides can be used to control protein adsorption at an air-water interface (Ganzevles et al., 2006). The interface of simultaneously adsorbed films (from mixtures of proteins and polysaccharides) and sequentially adsorbed films (where the protein layer is adsorbed prior to addition of the polysaccharide) are different. The presence of the polysaccharide at the start of the adsorption process hinders the formation of a dense primary interfacial layer (Ganzelves et al., 2008). These observations demonstrate how the order of addition of components can influence interfacial structure. This has implications for foaming and emulsifying applications. 

In a commercial context, the end use dictates the properties desired. For solution applications, the rheology of the polysaccharide, its ability to retain water, and its gelling tendency are often the most important. For solids applications, the thermal properties (e.g., and T ), the mechanical properties (e.g., stiffness, tensile, texture, and adhesion), and other features such as water content, crystallinity, and spatial heterogeneity are relevant. Many polysaccharides are used in interfacial applications, in which case the surface-active properties of the polysaccharide are important. 

Chang et al. (2010) studied the mechanical properties of chitosan nanoparticle CNP/TPS nanocomposites. When the CNP content increased from 0 to 6 wt%, the tensile strength increased from 2.8 to 10.8 MPa, while the elongation at break decreased from 59 to 23 %. This was attributed to the interfacial interaction between chitosan nanoparticles and the glycerol plasticized starch matrix because of the similar polysaccharide structures of CNP and starch. At CNP concentration of 8 wt%, the tensile strength showed deterioration, possibly due to the agglomeration of CNP. Thus CNP nanoparticles were also shown to have an optimum concentration in TPS, above which their mechanical properties decreased. 

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