straight chains called amylose, and short,
branched, bushy chains called amylopectin.
Plants deposit starch molecules in
microscopic solid granules. The size, shape,
amylose and amylopectin contents, and
cooking qualities of the starch granules vary
from species to species.
Linear Amylose and Bushy Amylopectin
The shapes of amylose and amylopectin
molecules have a direct effect on their ability
to thicken a sauce. The straight amylose
chains coil up into long helical structures
when dissolved in water, but they retain their
basically linear shape. Their elongation makes
it very likely that one chain will knock into
another or into a granule: each sweeps through
a relatively large volume of liquid. By
contrast, the branched shape of amylopectin
makes for a compact target and therefore a
molecule less likely to collide with others;
and even if it does collide, it’s less likely to