Food Biochemistry and Food Processing (2 edition)

BLBS102-c32 BLBS102-Simpson March 21, 2012 14:2 Trim: 276mm X 219mm Printer Name: Yet to Come

614 Part 5: Fruits, Vegetables, and Cereals

Table 32.1.Industrial Uses of Starch

Starch and Its Derivates Processing Industry Application

Amylose and amylopectin (polymeric

starch)

Food Thickener, texturants, extenders, low-calorie

snacks

Paper Beater sizing, surface sizing, coating

Textile Wrap sizing, finishing, printing

Polymer Absorbents, adhesives, biodegradable plastics

Products of starch hydrolysis, such as

glucose, maltose, or dextrins

Food Sweeteners or stabilizing agents

Fermentation Feedstock to produce ethanol, liquors, 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.

These molecules can thus be fractionated by utilizing differ-

ences in their molecular size as well as in their binding behavior.

Moreover, amylose is able to complex lipids, while amylopectin

can contain covalently bound phosphate, adding further com-

plexity to their structure. In nature, amylose normally accounts

between 20 and 30% of the total starch. However, the percent-

age of amylose depends on the species and the organ used for

starch storage. The proportion of amylose to amylopectin and

the size and structure of the starch grain give distinct properties

to different extracted starches (properties important in food and

industrial purposes; Dennis and Blakeley 2000). Starch grain

size is also dependent on species and organ type. It is well estab-

lished that starch grains grow by adding layers, and growth rings

within the grain may represent areas of fast and slower growth

(Pilling and Smith 2003); however, very little is known about

how these highly ordered structures are formed in vivo. The in-

terested reader is referred to articles by Buleon et al. (1998) and

Kossmann and Lloyd (2000).

Figure 32.1.Starch structure: Amylose (A) is classically regarded as an essentially linear polymer wherein the glucose units are linked

throughα-1-4-glucosidic bonds. In contrast, although amylopectin containsα-1-4-glucosidic bonds, it also consists of a high proportion of

α-1-6-glucosidic bonds (B).