Food Biochemistry and Food Processing

254 Part II: Water, Enzymology, Biotechnology, and Protein Cross-linking

biotechnology strategies. However, we will begin by
briefly describing starch, its structure, and its syn-
thesis.

WHAT IS STARCH?

For many years it has been recognized that the
majority of starches consist of two different macro-
molecules, amylose and amylopectin (Fig. 11.1),

which are both polymers of glucose and are organ-

ized into grains that range in size from 1 
m to more

than 100 
m. Amylose is classically regarded as an

essentially linear polymer wherein the glucose units

are linked through -1-4-glucosidic bonds. In con-

trast, although amylopectin contains -1-4-gluco-

sidic bonds, it also consists of a high proportion of

-1-6-glucosidic bonds. This feature of amylopectin

makes it a more branched, larger molecule than amy-

Table 11.1.Industrial Uses of Starch

Starch and Its Derivates Processing Industry Application

Amylose and amylopectin Food Thickener, texturants, extenders,

(polymeric starch) low calorie snacks

Paper Beater sizing, surface sizing, coating

Textile Wrap sizing, finishing, printing

Polymer Absorbents, adhesives,

biodegradable plastics

Products of starch hydrolysis, Food Sweeteners or stabilizing agents

such as glucose, maltose, Fermentation Feedstock to produce ethanol, liquors,

or dextrins spirits, beer, etc.

Pharmaceutical Feedstock to produce drugs and

medicine

Chemical Feedstock to produce organic solvents

or acids

Source:Adapted from Jansson et al. 1997, with modification.

Figure 11.1.Starch structure: Amylose (A)is classically regarded as an essentially linear polymer wherein the glu-
cose units are linked through -1-4-glucosidic bonds. In contrast, although amylopectin contains -1-4-glucosidic
bonds, it also consists of a high proportion of -1-6-glucosidic bonds (B).