Researchers grow fish fillets in laboratory

A team of researchers at Zhejiang University has grown China’s first centimetre-long fish fillets in the laboratory.

Developed over 17 days, the cultured fillets are indistinguishable from similar natural fish in flavour, colour and texture, according to the study published in the peer-reviewed Science of Food.

“Marine fish contain high-quality protein and unsaturated fatty acids, which have a positive effect on health,” said co-author Liu Donghong, a researcher at Zhejiang University.

“This technology may provide support for addressing the supply of meat and animal protein for human beings. It also has important implications for the conservation of marine fish stocks,” Liu said, on the university’s website.

Cultured meat – a product made by cultivating animal cells in a lab – has emerged as an alternative to partially replace the traditional livestock industry in meat production, according to the research team.

Some researchers and companies have developed meat tissues from cows and pigs with the help of 3D printing technology.

But there have been fewer studies on cultured marine fish because of the large diversity in muscle types among marine fish and a lack of supporting materials for a 3D scaffold to build the flesh structure.

For their study, the researchers cultured fillets of the large yellow croaker, using isolated muscle and fat stem cells to “seed” the cultured fillets, putting them in a culture medium to let them grow.

Fat stem cells grew well in the culture medium, but as the muscle stem cells grew and differentiated, the meat produced was just paste, the authors said. “At this point, the fish is still a loose mass of cells with no fixed shape. It doesn’t have the tissue structure that people perceive as meat,” said co-author Chen Jun, also a researcher at Zhejiang University.

The researchers constructed a gelatin-based 3D scaffold for the cells to grow on.

Compared with the natural fish tissue, the researchers found the cultured fillets similar in terms of the number and ratio of muscle and fat cells. But the chewiness of the cultured fish fillets was low and water distribution different to the naturally raised seafood, the authors said.

“In summary, we have successfully developed a pipeline for the production of tissue-like cultured fish fillet. It demonstrates that biomimetic scaffolds based on real tissue structure have a great potential in the production of tissue-like cultured meats,” they said.