Amylopectin depolymerization

The major constituent of starch, amylopectin, can also be analyzed after depolymerization [237]. As can be seen from the chromatogram in Figure 3.246,... 

Figure 3.246 Chain length distributions of amylopectins of different origin after depolymerization. Separator column Carbo-Pac PA1 eluent (A) 0.15 mol/L NaOH, (B)...

The most important natural binder still in use today is starch, though it is now frequently used in combination with synthetic binders. Com starch is more common in the USA, whereas potato starch is more prevalent in Europe. Native starch containing two fractions of amylose (linear chain) and amylopectin (branched chain) is not suitable for coating paper and board because the amylose fraction tends to undergo retrogradation and the viscosity of coating colors made with native starch is too high [5]. For these reasons, only treated (i.e., depolymerized) or chemically modified starches are used. Most paper mills carry out their own starch preparations in-house. 

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