Complexed starch

More complex starches are termed amylopectins and contain branched chains. Starches can be very large molecules indeed, with molecular masses ranging up into the millions. 

During extrusion, general browning typified by carameli-zation, Maillard, and oxidative decomposition reactions are paramount in flavor compound formation. Temperature and shear conditions occurring during extrusion can provide the chemical and physical means whereby complex starch and protein can be partially degraded to provide reactants that can then participate in browning. 

Boric acid is known to complex starch (see Section IV), and the same complexation takes place with the starch-iodine complexes. Figure 29 diagrams the assumed position of attached boric acid.159 As with starch, starch blue is capable of sorbing some dyes (Acridine Orange, Methylene Blue, and 1,9-dimethyl-methylene blue).225 This phenomenon is discussed in more detail in the accompanying article (p. 345). 

Sample, % GMS Dry Matter % Starch % Glucose % IBC Complexed Starch, % ... 

Nonionic food grade emuslifiers/ water/ limonene/ethanol/ propyleneglycol Molecular inclusion complexes Starch... 

Tomasik, P., Wang, Y.J., and Jane, J., Starch sugar complexes, Starch/Staerke, 47, 185, 1995. Tomasik, P. and Zaranyika, M.F., Nonconventional methods of modification of starch, Adv. Carbohydr. Chem. Biochem., 51, 243, 1995. 

In the context of this chapter, the use of thermoplastic starch in blends with thermoplastic resins is of the main interest. As shown in Table 16.11, several blends have been developed, e.g., with vinyl alcohol copolymers (EVAl), polyolefins, aliphatic polyesters such as poly-e-caprolactone (PCL) and its copolymers, or polymers of glycols (e.g., 1,4-butanediol) with succinic, sebacic, adipic, azelaic, decanoic or brassihc acids, PCL + PVC. Compatibilization is possible by amylose/EVAl V-type complexes, starch grafted polyesters, chain extenders like diisocyanates, epoxies, etc. [Bastioli et al., 1992, 1993]. 

Fiber comes in two forms soluble and insoluble. The most common insoluble fiber is cellulose, which is found in lettuce, carrots, bean sprouts, celery, brown rice, most other vegetables, many fruit skins, and pumpernickel bread. Insoluble fiber binds various molecules but otherwise merely forms bulk in the lower intestine. Soluble fibers include amylopectin and other pectins, as well as complex starches. Uncooked and mildly processed foods contain a higher proportion of this type of fiber. 

Surface sorphon complexes (starch surface hpids) are complexes of hpids bound to the surface of the granules. These are primarily triacylglycerols (TAG), followed by free FA, glycolipids, and phosphohpids. The surface hpid present depends on the origin of the starch (Vasanthan and Hoover, 1992). These hpids can be extracted with cold solvents (Barnes, 1987 Tomasik, 2000), but it cannot be ruled out that such an extract will also contain non-starch hpids that are absorbed onto the surface of starch granules during isolation procedures (Morrison and Coventry, 1989 Vasanthan and Hoover, 1992). 

Morrison, W.R. and Coventry, A.M. 1989. Solvent extraction of fatty acids from amylose inclusion complexes, Starch/Stderke, 44(1), 24. 

Dejewska, A., Mazurkiewicz, P., Tomasik, P., Zaleska, H. Electrochemical synthesis of polysaccharide-protein complexes. Part 1 preliminary studies on apple pectin-albirmin complexes. Starch 47(6), 219-223 (1995)... 

The market of destructurized and complexed starch-based bioplastics accoimts for about 25,000 ton/year, 75% of which is for packaging applications, including soluble foams for industrial packaging and films for bags and sacks. The market share of these products accoimts for about 75-80% of the global market of bioplastics (162). 

The wide patent portfolio of Novamont covers the technologies of complexed starch developed by Novamont and of destructurized starch developed by Warner Lambert and acquired by Novamont in 1997 after the exit of Warner Lambert from the market in 1993. Moreover, on August 2001 Novamont acquired the film technology of Biotec which included an exclusive license of the Biotec s patents on TPS in the sector of film (162). 

Bastiolo,C.,Bellotti,V.,DelTredici,G.F.,Lombi,R.,Montino,A.and Ponti,R. (1992). Complexed starch-containing compositions having high mechanical properties. International Patent Application WO 92/19680. 

Felker FC, Kenar JA, Fanta GF, Biswas A (2013) Comparison of microwave processing and excess steam jet cooking for sphemlite production from amylose-fatty acid inclusion complexes. Starch 65 864—874. doi 10.1002/star.201200218... 

This chapter reviews the main results obtained in the fields of starch-filled plastics and thermoplastic starch with a particular attention to the concept of gelatinization, destructurization, extrusion cooking, and the behaviour of complexed starch in the presence of specific synthetic polymers. The behaviours of products now on the market are considered in terms of processability, phyicochemical and physicomechanical properties and biodegradation rates. 

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