**6. Biodegradation**

Starch is a nutrient for many organisms and since water is present in the final structure the starch is readily biodegraded. Water can easily be absorbed by starch resulting in disintegration of the material by partial solubility. Partially solubilised starch is even more readily biodegraded by enzymes principally from microorganisms. Starch–poly(vinyl alcohol) blends were plasticised with glycerol and reinforced with unripe coconut fibres to form fully biodegradable composites (Rosa, Chiou, Medeiros, Wood, Mattoso, Syed, Inam, 2009)). Degradation rate slowed when fibre content increased, though crystallinity was not changed in the composites. The blend and composites degraded slower in composite that the pure TPS.
