Sustainable bioplastics from seaweed polysaccharides: A comprehensive review

The use of macroalgae for food has been extensive in Asia historically. However, there has been a renewed interest at present in macroalgae due to its recognition as a potential carbon capture agent and a blue carbon donor besides their utility in biofuel production. Bioplastics is an umbrella term for a wide variety of polymers that can be either biobased or biodegradable, or both. Macroalgal polysaccharides and their inherent film-forming capacity are exploited in the bioplastics industry and macroalgal polysaccharide-based biofilms are extensively used in food packaging due to their compatibility and ease of production. Commercial macroalgae-based bioplastics production is ongoing, with research dedicated to the development of biodegradable/compostable biofilms suitable for the food packing and biomedicine sector. This review aims to provide an overview of the polysaccharides of macroalgae that can be used to form biofilms and bioplastics. Different methods for biofilm formation are discussed along with summarizing the effect of plasticizers, the method of film formation, and biodegradability. The major source of marine macroalgal polysaccharaides are agar, alginate, carrageenan, laminarin, fucoidan, and ulvan. Different groups of macroalgae are utilized for the production of polysaccharide derived bioplatics, namely, brown algae (Padina pavonica, Ascophyllum nodosum, Laminaria japonica, Rugulopteryx okamurae, Sargassum natans, Sargassum siliquosum, Jolyna laminarioides, Gracilaria salicornia), green algae (Ulva fasciata, Halimeda opuntia, Codium fragile, Ulva intestinalis, Ulva lactuca, Ulva rigida), and red algae (Eucheuma cottonii, Porphyra sp., Kappaphycus alvarezii, Gracilaria corticata). The outcome of the review reveals that there is a vast scope for macroalgal polysaccharide-derived bioplastics for a sustainable environment.