Project Turns Fish Waste into Value-Added Products

Only about 50per cent of every fish sold as fillet is actually eaten. Often, fish heads, viscera, skin and bones are discarded. In this context, the SECUREFISH project, funded by the EU, aims at reducing the post-harvest waste in the fisheries sector while improving the overall environmental friendliness of fish processing in developing countries.

We use the waste products that include fish skin and bones and process the proteins through hydrolysis into bioactive peptides, explains project co-ordinator Nazlin Howell, Professor of Food Biochemistry, University of Surrey, Guilford, UK.

Scientists have discovered that some of the bioactive peptides isolated from fish waste exhibit an activity akin to that of a class of blood pressure lowering drugs called ACE inhibitors. Others also exhibit antioxidant properties and might reduce reactive oxygen species in cells. Such activity could have implications for cardiovascular disease and cancer prevention. Howell tells youris.com [these] could be put into [food] products such as yoghurt and milk drinks due to their potential health benefits.

Some experts welcome the idea of turning these peptides into neutraceuticals. The exploitation of bioactive peptides in waste materials is very new and a very good idea because otherwise they are just discarded, says Elizabeth Lund, an independent consultant specialised in nutrition and gastrointestinal health previously a scientist at the UK Institute of Food Research, in Norwich.

The project goal is to test the entire process of converting these bioactive peptides to high-value products directly in developing countries.

The next step, will involve field trials incorporating progress made by other project partners to make fisheries a greener activity.

Howell explains: We will bring together the [fish conservation] processing tools, the total quality management tool [to assess environmental, health and safety aspects] and the newly developed functional proteins and peptides and use them to make new [food] products in the developing countries.

In particular, case studies will be implemented in Africaincluding Kenya, Namibia, Ghanaand Asia, namely India and Malaysia, as well as Argentina.

If this is aimed at developing counties then any inexpensive protein source would be welcome and production might well be fairly straightforward," Lund remarks.

However, she warns: If the science is aimed at producing peptides with specific biological properties then these are likely to be much more expensive to produce and certainly require more research.

Trials designed to demonstrate the peptides health effect would then be required.

We would like to take the application of peptides further to make them available to consumers, says Howell. Despite its potential health applications, this approach may not entirely meet the projects environmental objective.

Extracting skin or bones to make hydrolysates or peptides, while possibly adding value to the process, does not solve the original problem: getting rid of the bulk of the waste," says Anthony Bimbo, technical consultant at International Fisheries Technology consultancy, based in Kilmarnock, Virginia, USA.

He believes the priority is elsewhere.

For developing countries, where much of the waste is generated now, you need simple systems to, first of all, recover and utilise the raw material before attempting to work on sophisticated value added products, he tells youris.com, [the latter] seem to be more directed at developed countries with established systems for by-product recovery and where companies are looking for value added products to improve their bottom line.