Potato starch based trays can be foamed with
a relatively high content of corn fibers. Corn fiber is
not a reinforcing fiber for starch-based foam trays. The
tensile strength and flexibility of the trays decrease with
increasing fiber content. The addition of PVA to the
formulations mitigates the reduction in tensile properties
seen when corn fiber was added alone. Increasing
the fibers content increases batter viscosity, thus increasing
baking time. The fiber also interferes with
foaming so additional batter volume is needed as corn
fiber increases to form complete trays. PVA can be
added to the formulation as a dry powder, avoiding
the time and energy consuming step of dissolution. The
addition of corn fibers and PVA together decreases the
water absorption in the foam. The largest decrease
in water absorption was seen with the addition of
high molecular weight PVA. Corn fiber along with the
addition of PVA to potato starch is a viable option to
improve moisture resistance of foamed trays. Trays
containing 28.5% corn fiber and PVA-PH had tensile
properties that were the same as trays containing only
starch, but with better water resistance. For corn fiber to
have a greater impact on starch foam trays, the aspect
ratio of the fiber needs to be changed so the fiber will
have more reinforcing properties.