Pectin,consisting of1,4-linkedα-D-galacturonicacid,is a complex anionic polysaccharide present in the cell wall of many fruits and vegetables .
Additionally, chitosan, β(1→4)-2-amino-2-deoxi-D-glucosa or D-glucosamine, is a natural polymer derived by deacetylation of chitin, which is a major component of crustacean shells (crabs,shrimps,andcrawfish).
This compound, which has been used to elaborate ECs, is a cationic polysaccharide that exhibits bactericide and fungicide activities .
Finally, pullulan is an extracellular linear homopolysaccharide that is formed by maltotriose and maltotetraose units having both α-(1→6) and α-(1→4) linkages.
Produced by Aerobasidium pulluans, pullulan is capable of forming edible films and coatings. However, this polymer has not yet been thoroughly explored as a coating or packaging material .