The effects of chemical modification on process
parameters and foam plate properties are shown
in Tables 1 and 2. Plates made with unmodified
cornstarch have a smooth surface, but will occasionally
have cracks. No cracks were seen in
plates made with hydroxyethyl (HE) starch. Also,
batter volume and baking times required for the
latter were less than unmodified cornstarch. Hydroxyethylation
causes the starch to gelatinize
more quickly (at a lower temperature), and thus
the starch paste can then expand into a foam and
dry more rapidly.
There were no cracks in the modified starch
foams probably because chemically modified
starch granules will usually dissolve more completely
in water and thus form a stronger and
more continuous film. Strength (Fm) values for
the HE starch foam plates, as shown in Table 2,
were lower than the unmodified starch plates due