Pectin-based biodegradable water insoluble films

Aqueous solutions of pectin, an acidic polysaccharide which occurs in vario us natural products, was cast into clear films. While the films were flexib le enough to be used as wrapping materials, their strength and resistance t o water were inferior to presently used commercial films. However, precast films immersed into aqueous solutions of multivalent cations became insolub le in water and depending on the ions became stronger in tension. Tensile s trength increased to levels comparable to, or in the case of calcium, coppe r(II) and zinc, greater than those of some commercial wrapping materials.