GEA highlights injection technology for seafood product processing

Injection technology can better preserve flavour and shelf life of seafood products

Fish production is not without its challenges. How do you maintain consistency of distribution, quality and yields of the catch for seafood producers? Moisture and proteins can be lost from sea to plate, affecting the texture of the finished product. Injecting brine can help to reduce the lost moisture and restore the succulent texture, but given the somewhat fragile nature of raw fish, a sensitive process is needed.

Following in the footsteps of the meat industry, where injecting brine is essential for products such as cured bacon, cooked ham and poultry, there is now precise technology for the brining of a variety of fish, including cod fillets, salmon and mackerel. Accurate brine distribution coupled with high frequency shaking technology helps to maximise the value of seafood products.

The effectiveness of injectors is attributable to the density of the needle pattern, with the use of small needles in a dense pattern enabling better process control. Flavours are locked in, shelf life is enhanced and the delicate structure of the fish remains intact.

GEA Food Solutions has recommended injecting with a tight needle pattern with 2mm needles in diameter. Seamless integration of upstream and downstream operations such as brine preparation, brine chilling and shaking systems also ensures stable product quality from the fish processor to the end-consumer.

There are many reasons for injecting fish with brine — improving flavour, increasing shelf-life, yield and reducing food safety issues for cold smoked fish products. Brines include salts and additives, which prevent bacteria like listeria taking hold and ensuring that a more consistent product reaches the consumer in perfect condition.

In order to produce the best results it is important that the brine used during injection is carefully managed. The optimal brine temperature for injection is between 2°C and 4°C. When not regulated, brine temperature fluctuates due to the influence of the surrounding environment and pumping and filtration steps of return brine. Temperature control equipment cools the brine to a stable temperature range. This reduces the variation in injection pick-up and post-injection purge, further aiding retention and contributing to yield.

Shaking the fish closes the needle marks and shakes off excess brine while activating proteins within the fish improves its water holding capacity. Examples from the field: yield for trout is improved between 1-2% after shaking compared with control product that was not shaken. This provides economic benefits for processors, improved mouthfeel and taste for consumers and better results following further processing such as cooking, as moisture is better retained.

Trials of injection technology conducted by a Danish fish processing company in collaboration with GEA showed excellent results for cod fillets. The fillets were indistinguishable from fresh cod fillets but taste, mouthfeel and the general structure were all positively enhanced. Similar impressive results have been reported for salmon.

In terms of further processing, complete line solutions are available on the market. Formed products such as fish fingers can be produced using a plate forming machine which is ideal for fish as it is highly tolerant of any deviations during the process, allowing strong structure retention, even with delicate products.

For cooked products, a three-zone spiral cooking concept can gently but thoroughly cook the fish from top to bottom and left to right. Smoking can also be incorporated during this stage, for hot-smoked salmon for example. Also GEA packaging solutions can be applied to seafood lines, using rigid and/or flexible films.