Alginate based sustainable films and composites for packaging: a review

Abstract

Alginate is an abundantly hydrophilic polysaccharide as much as 40 % of dry weight and commonly available in the cell wall of brown seaweed. The thickening, gel-forming and stabilizing properties of alginate makes it widely used biopolymer with a broader range of application including packaging. The superior valuable feature of alginate is the capability to yield a stable gel and insoluble polymer when they react through their carboxylate group with polyvalent metal cation especially Ca2+. Despite a wide range of applications, alginate has some drawbacks on the water resistivity due to hydrophilic nature, so its modifications with synthetic and natural polymers are carried out. This review article presents a different type of additives or polymer and their impact on the functional properties of alginate based composite films with special emphasis on packaging application.