The good fish served at table starts from a good cold chain

Speaking of cold in the fish sector is very important. The catch value in the world, according to Statista, is constantly growing and is likely to rise from about 120 billion dollars in 2016 to over 155 billions in 2023. Therefore, the refrigeration is a fundamental element to grant quality and the compliance with hygienic-sanitary standards, besides enhancing the taste characteristics, too.

Valentina Tepedino

However, what is the … right cold? How can we grant it and how can we manage the entire cold chain? Valentina Tepedino, veterinarian specialized in the fish sector and national reference person for the fish sector for the Society of Preventive Veterinary Medicine, answers these questions. Moreover: she is the general manager of Eurofishmarket, consulting, education and information company of fishing and aquaculture on the environment. She was scientific consultant for Rai and also for Mediaset, for broadcasts like “Linea Blu” or “Pianeta Mare”, and also for other TV and radio channels.  

What are the best solutions for refrigeration in the fish sector?

The fish sector is a very complex ambit and also the management and the maintenance assured by the so-called “cold chain” are not simple. From fishing to distribution and finally to consumers’ tables, the road is very long indeed and steps might be manifold and very different one another. I will make some examples, to explain better. If the fish is caught on the boat, there is usually a refrigerated cell where the product is kept in water and ice, once landed generally in disposable polystyrene boxes and ice for the various destinations (market, wholesale, retailer, shop, restaurant and so on,) and then it will be shown in counters, in ice, in fishmongers or it will be processed and conserved in restaurants’ refrigerators. According to my experience, I can say that, more than the useful equipment to grant the cold chain, their management, and of the fish product in relation to them, matters.

What are the major criticalities in the sector?

They are determined by a bad management concerning what above said: fish not refrigerated immediately after fishing, fish left too much time in standby between one supplier and the other, or from the cell to the counter and from the counter to the restaurant or the customer’s house. Therefore, in my opinion, the most sensible innovations are those that combine the traceability control to the cold chain management: therefore, refrigerated cells that monitor temperature by automatically registering it, refrigerated vehicles or isothermal containers that grant as much as possible an upstream control on the correct maintenance of the cold chain. Concerning this, there are not many innovations regarding the fish sector and this often implies a shorter duration of products’ commercial life and a consequent waste and economic damage for the whole production chain.

Is it advisable to provide for a determinate kind of refrigeration for each fish variety?

Actually, ideal would be to increasingly shorten the chain in the future, not according to the zero Km (mile) principle, hardly feasible, but drastically diminishing the passages between producer and distributor. I confirm: especially in passages, non-optimal sudden temperature changes for the life of fish products generally occur. Moreover, market surveys are proving a steeply rising growth of ready to eat and ready to cook fish products that certainly will have to be managed in the future with the so called “smart labels” to know whether they have been subjected to sudden temperature changes from the production onwards. Big fishes, like yellow fin tunas and swordfishes, are more and more delivered in slices and fillets, vacuum or in modified atmosphere. Certainly, it would be useful to research further on ideal conservation systems to extend the shelf of fish products without necessarily using additives in addition to the product. Some years ago, together with the Veterinary University in Padua and with the Society of Preventive Veterinary Medicine we carried out a research to understand better the different duration between a slice of yellow fin tuna in modified atmosphere (MAP) and a vacuum one. We deduced that, naturally with the right proportion of the various gases, the yellow fin tuna in MAP has a longer duration. These researches are important because, besides finding useful solutions to preserve the product longer, they must also assure the maintenance of the most pleasant outer look. A tuna that gets dark brown, although well refrigerated, will be hardly sold. Likewise, a red or purple shrimp, or of whatever species, even if properly refrigerated shortly after its death, will show a sort of dark spot on the head and it will not be easily sellable, hence the addition of permitted additives. Ideal would be to succeed in marketing live crustaceans, but in this case we should face the important issue of live fish products, which is much debated as there is not a clear guideline by official bodies with competence on the matter and a specific legislation. Molluscs, for instance, must be marketed alive and vital, and they must be as such at the purchase time. For these products, the refrigeration is carried out with useful ventilation systems to avoid the direct contact with ice, which would cause their death.   

How should cold be used in general?

Ideal would be to pay attention to “dosing” cold in the same way in the whole box and on all contained products, and the same should happen also during their exposure on the counter, implementing some useful arrangements for the goal, avoiding heaps and achieving a good “arrangement” with ice. The ice quality as well, or better its size, has a relevance, as well as the way in which it is positioned around the product.

Is a determinate refrigerating action necessary or preferable for the conservation until the sale counter?

The most important thing would be avoiding the interruption of the cold chain. For many products, a wrong management might shorten their commercial life and ruin their original sensorial and nutritional characteristics, in some species, belonging in particular to some families of fishes, like anchovies, sardines, the different species of “tuna” or small tunas, auxis species or mackerels. An interruption of the cold chain might instead lead to much more serious consequences, affecting consumers’ health. In fact, the above-mentioned species and still others, if badly managed, might cause the so-called mackerel syndrome, with the degradation of histidine generally contained in them into histamine. Essential requisite to avoid the formation of histamine is precisely the severe compliance with the cold chain.

What are the sector’s evolutions in its requirements of optimal catch conservation?

In the future, we will increasingly study and apply useful technologies to provide ready-to-use fish products suitably processed for lasting longer. Moreover, the suppliers of fish products will become increasingly determinant and reliable, as they will be able to provide warranties, registrations or certifications about the correct maintenance of the cold chain along the entire production chain. I think that isothermal “smart” containers, – i.e. those that combine electronic microsystems able to monitor and then to control products along their entire course – are an innovative highly strategic product for both the said target, the fight to wastes and the environmental sustainability. One of the most innovative solutions is based on an App and a WebApp that dialogue to collect, to store and to manage traceability data. This “dialogue” occurs through the RFID technology, more and more used in logistics and distribution. Through the specific cloud, users can browse the data transmitted by their Apps, carry out researches with various filters and export data to produce statistics. The most innovative products can also print “Certificates of Conformity to the Traceability system”. This document certifies the traceability of the occurred operation to track in detail the shipments and the deliveries of meals and foods, monitoring them along the whole distribution chain. This technology is strategic in the deliveries of the collective catering dedicated to school and hospital canteens and also for restaurateurs who often do not use refrigerated vehicles for fish provisions at present. Cold technologies as well, like the freezing at very low temperatures, are starting spreading in the fish sector and they are under study phase for the costs/benefits estimate especially in yellow fin tunas’ slices.