Some Essential Preservatives Used in Fish Processing
The oceans have been a rich source of nutritious foods since humans first developed the art of making simple tools and weapons. The range of marine creatures is enormous, and new species are still being discovered. Once, the fruits of the sea were only available to those who lived sufficiently close to a port. However, fish-processing technology and food preservatives have since made these tasty delicacies available to consumers worldwide.
Only a relatively small proportion of the seafood landed will find its way onto a fishmonger’s slab. Preservation in ice is often sufficient in such cases as stocks generally sell out quickly. However, the bulk of a catch is destined for factories where they will undergo various processes to ready them for sale. Most consumers are busy, and although they enjoy a cooked meal, they lack time to prepare it from scratch. Instead, fish-processing factories create products like breaded or battered cod and hake fillets to meet their needs. Canned foods make convenient snacks. Hence tuna, salmon, sardines, and mackerel are commonly sold in this form. However, seafood must be suitably preserved before it can be processed as required.
One of the main problems facing the industry is the rapid deterioration of seafood once removed from its natural environment. Firstly, most marine creatures are the unconscious hosts of numerous bacterial species. Occasionally, these may pose a threat of food poisoning. However, while preservatives used in fish processing can eliminate this risk, they have many additional roles. Much of the seafood we purchase today is pre-packaged and frozen, giving consumers the option to cook it when and how they please. While freezing extends the shelf-life of these products, it is not sufficient to ensure they retain their characteristic colour, taste, and texture. Any noticeable deviation from the accepted norms is almost certain to deter the average consumer.
In practice, the first thing most people rely on as a measure of quality when purchasing seafood is its colour. Crustaceans destined for fish processing, such as prawns, should have a characteristic pink or white hue. Unless suitably treated, however, they rapidly develop black streaks due to a post-mortem chemical reaction between an enzyme and an amino acid naturally present in their flesh. The phenomenon is known as melanosis. Although it does not affect the taste or safety of crustaceans, it invariably provokes an adverse reaction from consumers. A short immersion in a solution of a suitable additive is sufficient to prevent the onset of melanosis.
Highly coloured species, like red snapper, tend to fade once landed. Consequently, fish-processing plants must also rely on chemical preservatives to inhibit loss of colour. A harmless stereoisomer of vitamin C, known as sodium erythorbate (E316), combined with sodium citrate (E-331) and citric acid (E-330), can prevent this unwanted fading. By contrast, darkening due to enzymatic action in naturally white species can also generate adverse consumer reactions. Once again, one can avoid this phenomenon with suitable preservatives. In this case, 24 hours immersed in a weak solution of sodium ascorbate and citric acid will do the trick.
Tequisa is a specialist developer of essential preservatives for the fish-processing industry. Please click here to learn more about these and other products in our marine range. Contact us today.
