Thermal processing, polysaccharides

There is a concern about harm coming from the free radical character of caramels. However, they were proven (Barabasz et al., 1990) to be nonmutagenic. Thermal processing of saccharides and polysaccharides containing foodstuffs... 

This chapter on saccharides is divided into two main parts. The first part describes major monosaccharides, and their functional derivatives, oligosaccharides and polysaccharides. Their structure and nomenclature, occurrence in major food commodities, properties and importance in human physiology and nutrition, recommended intake and use in food technology are all described. The second part is devoted to reactions of saccharides that lead to the formation of products that influence odour, taste and colour of foods, and to reactions taking place during storage and thermal processing of food raw materials and foods. 

PHB is the energy storage material for certain bacteria and efforts to commercialise it and its copolymers as structural and package materials have not been successful due to their high costs and the difficulty in thermal processing. PLA from the polymerisation of lactic acid, a fermentation product of low cost polysaccharides, is a product which is produced from a combination of biotechnology and chemical technology. PLA and its copolymers are the subjects of this review. There have been many reviews published recently, especially related to the biomedical application areas, and thus only major current work is covered here. 

The unusual thermal stability and water uptake properties are due to the formation of a three-dimensional network in polysaccharides at high processing temperatures [12]. 

The degradation process has a free radical mechanism. It is initiated by free radicals P that appear due to, for example, hydroperoxide decomposition induced thermally or by trace amounts of metal ions present in the polysaccharide. One cannot exclude even direct interaction of the polysaccharide with oxygen in its ground triplet state with biradical character. Hydroperoxidic and/or peracid moieties are easily formed by oxidation of semiacetal chain end groups. The sequence of reactions on carbon 6 of polysaccharide structural unit that ultimately may lead to chemiluminescence is shown in Scheme 11. 

This chapter focuses on some aspects of phase transition behavior and other material properties of starch, particularly as they pertain to the structural order and interactions of the starch polysaccharides with water, lipids and other solutes. Understanding the thermally induced structural transitions of starch is helpful in controlling its physical properties and processing behaviors (e.g. plasticization, viscosity), as well as in designing products with improved properties (e.g. texture, stability). 

Appelqvist, I.A.M. Cooke, D. Thermal properties of polysaccharides at low moisture an endothermic melting process and water-carbohydrate interactions. Carbohydr. Polym. 1993, 20. 

Many liquid detergent products contain components that serve as product viscosity modifiers, added to achieve the desired consistency of the commercial product. Cellulosic polymers, for instance, are an excellent example of such an additive and various polysaccharides are capable of gelation under specific thermal conditions. In such cases, heat transfer during manufacture may be required to complete hydration and effect the necessary conformational change in the select polymer system [85], in the appropriate aqueous environment. Products requiring controlled heat transfer processes may include various dental creams, shampoos, built liquid detergents, and hard surface cleaners. 

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