Protein-polysaccharide blends

Like polysaccharides, proteins impart texture and structure to foods. Protein-polysaccharide blends may assume physical, ionic, or covalent character, may be soluble or insoluble, and may sometimes exhibit synergism. The characteristics of the blend are as much a response to the reaction environment as to the properties of each ligand. 

Recent studies on mannan-based blends and composites are emphasized on the use of KGM as a film forming component, with a few smdies on other mannans (Table 9.3). Even though films from pure KGM have excellent mechanical properties, the improvement of those properties has been sought by blending KGM with other polysaccharides, proteins, or synthetic polymers. 

In the past few decades, several biopolymers have been examined for their uses as modifying components in rubber blends. In this chapter, the use of biopolymers such as lignin, polysaccharides, proteins and polyesters to produce blends with NR are discussed. 

In this chapter, solid-state structure and properties relative to the morphologies of several chemically and bacterially synthesized biodegradable polymeric materials are described based mainly on the results obtained for bacterially synthesized polyesters by high resolution solid-state NMR spectroscopy. This chapter briefly discusses polymer blends, which also includes polysaccharides and proteins, since more details are given in other chapters of this book. Several books on biodegradable polymers have been published [1,2], and many review articles on structure and properties of bacterially synthesized polyesters have also been published elsewhere [7-10, 19-22]. 

Recently, our research attempted to find new materials based on blends of biological macromolecules, such as structural proteins and polysaccharides, and hydrophilic synthetic polymers, such as poly(vinyl alcohol) (PVA), in which the biocompatibility of the former is combined to the mechanical properties of the latter ((. ... 

In order to preserve the final compostabihty, different blends of biodegradable materials have been developed. There is a vast body of literature available in this domain. We find certain associations with agropolymers such as proteins [ARV 99, FIS 00, OTA 99] or pectins [FIS 00], but most research focuses on blends of plasticized starches and biodegradable polyesters PCL, PHA, PBSA, PBAT, etc. These polyesters, described previously, are produced industrially. They exhibit interesting properties such as a more hydrophobic natiue, limited water permeability and improved mechanical properties, in comparison to polysaccharides. However, the cost of biodegradable polyesters is generally higher than that of starch... 

Biomaterials have been defined as materials which are compatible with living systems. In order to be biocompatible with host tissues, the surface of an implant must posses suitable chemical, physical (surface morphology) and biological properties. Over the last 30 years, various biomaterials and their applications, as well as the applications of biopolymers and their biocomposites for medical applications have been reported. These materials can be classified into natural and synthetic biopolymers. Synthetic biopolymers are cheaper and possess better mechanical properties. However, because of the low biocompatibility of synthetic biopolymers compared with that of natural biopolymers, such as polysaccharides, lipids, and proteins, attention has turned towards natural biopolymers. On the other hand, natural biopolymers usually have weak mechanical properties, and therefore much effort has been made to improve them by blending with some filler. 

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