Researchers fish for healthy proteins

Food processors might soon be fishing for skeletons, with research suggesting that an alternative source of proteoglycans and chondroitin sulfate for health food formulations is found in high quantities in bony fish heads. The study, performed by academics at the Tokyo University of Science, looked at how different bony fish could have important and healthy proteins in their cartilage, which is often discarded by food processors.

Aggrecan, a major component of proteoglycan (PG) having chondroitin sulfate (CS) in cartilaginous tissues, has become increasingly popular as an ingredient in health food. Currently, commercially available chondroitin sulfate proteoglycans (CSPGs) are prepared only from salmon nasal cartilage found in salmon heads. Prior to this study it was known that other bony fishes had cartilage in their heads but information was scarce about the protein composition of this cartilage.

The Japanese research analysed the cartilage of 10 fish to understand whether they might also be able to provide aggrecan and the study found that all the bony fish tested had some level of proteoglycans. This is important for food processing as the cartilaginous parts of the fish are usually thrown away; this research suggests that these parts may be able to be used as a source of aggrecan.

“Head cartilage from bony fishes is an underutilised resource and is typically discarded after food processing,” said Dr Kyohei Higashi, one of the study’s authors. “The PGs, especially from the sturgeon, are similar in CS structure to the salmon nasal cartilage, showing that the sturgeon has a lot of potential to be an alternative source of CSPGs for health food formulations.”

The researchers are now hoping to continue their research on bony fishes, and sturgeon in particular, to understand how they might be a good source of proteoglycans for health foods.

The research was published in the International Journal of Biology Macromolecules.

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