Development of edible films and coatings from alginates and carrageenans

The use of renewable resources, which can reduce waste disposal problems, is being explored to produce biopolymer films and coatings. Renewability, degradability, and edibility make such films particularly suitable for food and nonfood packaging applications. Edible films and coatings play an important role in the quality, safety, transportation, storage, and display of a wide range of fresh and processed foods. They can diminish main alteration by avoiding moisture losses and decreasing adverse chemical reaction rates. Also, they can prevent spoilage and microbial contamination of foods. Additionally, nanomaterials and food additives, such as flavors, antimicrobials, antioxidants, and colors, can be incorporated into edible films and coatings in order to extend their applications. Water-soluble hydrocolloids like polysaccharides usually impart better mechanical properties to edible films and coatings than do hydrophobic substances. They also are excellent barriers to oxygen and carbon dioxide. Recently, there has been much attention on carrageenan and alginate as sources of film-forming materials. Thus, this review highlights production and characteristics of these films.