Wrapping sea bass in its own cling film: new materials from fishery waste

Professor Maurizio Selva

What do the sea bass in the fridge and the cling film that it is wrapped in have in common? In the near future, they could be made of the same material. In fact, scientific research on the transformation of fishery waste into products with high added value is making progress. At Ca’ Foscari a process has been developed to produce cling film from the scales and skin of local fish, such as sea bass and mullet.

“Today, 40% of the mass of fish is waste that is difficult to dispose of. Very often we just treat this waste to obtain flour,” says Maurizio Selva, professor of Organic Chemistry at the Department of Molecular Sciences and Nanosystems of Ca' Foscari University of Venice. “However, when we produce fertilisers or animal feed we waste a wealth of very interesting molecules that could be used to make innovative and non-innovative materials, and much more. Thanks to the protocol that we have just developed, we can obtain completely natural and biodegradable collagen films, and we can also modify their optical and mechanical properties.”

UV-resistant cling film

The experimentation went further. From the same raw material, sea bass scales and skin, Ca’ Foscari scientists also obtained carbon nanoparticles, known as carbon dots, which were enhanced by the natural high nitrogen content. The discovery was published in the scientific journal Nanomaterials.

These carbon nanoparticles can be used as additives to make the collagen films luminescent when hit by ultraviolet rays and to modify their tensile and breaking strength. By exploiting these properties, innovative products can be introduced into the market. This film could be used to create a cling film that is transparent, resistant and luminescent, which can also protect food from UV rays.

Exploiting local diversity 

Ca’ Foscari scientists have tried to exploit biomass from local waste which is available at the local fish market - which is why they focused on the potential of sea bass biowaste. By doing so, they have laid the foundations for the enhancement of a local product and for a possible leap from the academic laboratory to the industry. However, each coastal area can use its own local fishery waste, depending on the specific chemical characteristics of the species available in that area.

Furthermore, each fish can offer multiple substances for use. For example, fish bones are made of hydroxyapatite, which can be processed and used as a nano-reinforcing agent in innovative materials. In the future, every part of a fish may be used. 

Advanced biorefinery

According to Selva, “Research in the field of waste biomass management will promote the development of a new generation of biorefineries. In the past we used to be satisfied with processes that would use a single resource to generate a single product, such as biodiesel and rapeseed oil. However, with today’s technology we can exploit different types of biowaste and obtain a great number of products, which can be used in different ways in the material, cosmetic and nutraceutical industries.” 

Cutting-edge research

At an international level there is a growing interest in discoveries such as the one made by Professor Selva and his team at the Department of Molecular Science and Nanosystems of Ca’ Foscari University of Venice. In fact, in 2020 the Royal Society of Chemistry stated that Professor Selva was in the top 1% by citations in its journals.

Moreover, Professor Selva received funding from the Organisation for Economic Co-operation and Development (OECD) to develop studies on the use and ‘upgrading’ of fish biowaste, in collaboration with the University of Sydney. Professor Selva also supervised the publication of a review on the state of the art of molecule and bio-material extraction from fish and crustacean biowaste, which was published in the journal Chemical Society Reviews. 

Enrico Costa