Biodegradable Polymers Extracted from “Sargaço”: Film Properties and Application to Edible Coating

Abstract

“Sargaço” is the name given to a mixture of dead seaweeds collected on Portuguese beaches. “Sargaço” is composed of algae containing biopolymers such as carrageenan, alginate and agar which are extensively used in food and pharmaceutical industries as gelling and stabilizing agents. The objective of this work was the biopolymers extraction from “Sargaço”, collected at Leça da Palmeira-Portugal, for production of biodegradable films and subsequent application in edible coatings for food. A mixture of biopolymers was hot-extracted from alkali treated “Sargaço”. Films were made from an optimized extract, using the knife coating technique. Films physical properties were characterized and results show that biodegradable films from “Sargaço” are more hygroscopic, less elastic, more deformable, and more permeable to water than films obtained from a commercial alginate and a domestic κ/ ι-hybrid carrageenan developed during previous studies. As such, this mixture of biopolymers is an interesting cheap alternative to produce biodegradable materials and a potential application to fresh fruit preservation has been tested.