SPAIN – Biodegradable materials obtained from the surplus of these crustaceans are based on low density polyethylene.  With flour crabs and biodegradable synthetic polymer PCL have managed to improve the mechanical properties of these bioplastics, exceeding the performance of conventional plastics.

“We have also observed that the amino acid L-cysteine can exercise as crosslinking agent, playing a crucial role in the formation of new protein from red crab,” says researcher Manuel Felix Angel from US.

Spain is the third largest producer of American red crab, after US and China, which still gives more importance to these studies.  “Our goal is to develop a product with higher added value than flour crab which is marketed today, for we have developed emulsions mayonnaise-type, food gels and bioplastics,” said the authors of this study, published in the journal Composites Part B Engineering.

American Red crawfish from Guadalquivir is not marketed as a foodstuff in Spain (even with an excellent amino acid profile) but becomes a by-product in the form of flour where the protein has been denatured and has lost much functional capacity.

“Although a lot of this crustacean to the Nordic countries is exported, shellfish processing plants generate a significant volume of waste that is not usually used for food purposes and we took advantage,” say the researchers.

The processing is done in three stages.  First natural protein bonds are broken, then the polymer chains are reorganized so that there is finally new interactions and new bonds are formed by injection molding on a small scale in the laboratories of the Faculty of Chemistry.

These results are part of the project of excellence products and waste valorization of the red crab industry based on its protein content, funded by the Ministry of Economy, Innovation, Science and Employment of the Junta de Andalucía.