Technological watch

This review on carrageenan?based wraps aims to give a literature overview of the sources of carrageenan, modification methods and applications in food preservation. The quick?drying properties, mechanical properties, water resistance and antibacterial properties of carrageenan fresh?keeping wraps can be enhanced by different modification methods. Finally, the applicability of carrageenan?based wraps and the future direction of development are discussed.ABSTRACTAs a polysaccharide extracted from marine red algae, carrageenan has the advantages of biodegradability, nontoxicity and water solubility over petroleum?based plastics for use as films and coatings for keeping food fresh. Aqueous solutions of carrageenan can be cast into films on plates and then made into food packaging bags, as well as coated directly onto food surfaces, all of which are referred to as ‘wraps’. To overcome the inherent limitations of carrageenan as a packaging material, physical and chemical modifications have been studied. The mechanical, thermal, barrier and antibacterial properties of modified carrageenan make it widely applicable for extending the shelf life of food products and monitoring its freshness. The research progress of carrageenan?based wraps in recent years has been reviewed in terms of preparation methods, physicochemical properties, gelation mechanisms and applications, and the factors affecting the drying rate of them have been analysed. Finally, applications and future research directions of carrageenan are summarized and discussed to provide useful guidelines for further research.