The key to reducing the amount of salt in cod is to partially replace sodium with potassium after the desalting process.
"Once we have desalted the cod, we introduce a piece of it in a solution containing potassium chloride. During this process, a partial exchange of sodium for potassium takes place – it is like a second desalting. Thus, we get a piece of cod containing 50 per cent less sodium than standard desalted cod,” says José Manuel Barat, a researcher at the UPV’s CUINA group.
The fish also retains all its properties of flavour, texture, etc., as show the results of several sensory studies that have been conducted in the UPV’s laboratories. It also contains enough salt so that it can be stored under refrigeration for as long as is needed. So far, this new technique has been applied, and validated, in laboratory tests.
This new method proposed by researchers at the UPV’s CUINA group responds to an increasingly important demand by the food industry for developing low-salt products.
"With this technique, we open the door to offering a new product both to those consumers who, for medical reasons, must have little salt in their diet, and to the general public, who are advised to reduce their sodium intake. Furthermore, by replacing sodium chloride with potassium chloride we get an even healthier product," says Mr Manuel Barat.
Researchers at the UPV’s CUINA group have extensive experience in the processes of salting and desalting food. They also have several patents, including a method for desalting and preserving fish.
This experience and this knowledge were applied to a collaborative project with the fishing industry company Conservas Ubago, which resulted in the commercialisation of ready-to-cook refrigerated desalted cod.
"Even though it was desalted cod, it still had a certain amount of salt, as it is necessary in order to store refrigerated cod. Now we have gone a step further, and have reduced even that sodium content. We have thus laid the ground for the development of a new product, with less sodium and more potassium, with all its properties unaltered, particularly suitable for diets with a low sodium content," said Mr Manuel Barat.
This research has been published in the Journal of Food Engineering.