It happens to everyone: cooking a salmon steak in the oven, steaming it, or pan-frying it, only to see a kind of white, gelatinous coating appear on the surface. This isn't fat, as many people believe, but a protein found in fish (and other foods) that coagulates. This is albumin, primarily found in egg whites, but also present in our bodies, where it plays a key role in many biological functions. Let's take a closer look at what it is and what it does.
What Happens When You Cook Salmon
When you cook a salmon steak, the fish's muscle fibers contract and push out part of the fluids contained in the tissues. Among these is a certain amount of albumin, a water-soluble protein. As soon as the heat reaches a temperature of around 140-150°F/60-65°C, this protein denatures —that is, changes structure—and coagulates, becoming visible as a thick, whitish substance. This isn't harmful and doesn't affect the flavor of the food, but it's simply unsightly. The reaction is similar to that which occurs when you cook egg whites: transparent when raw, they become white and solid once cooked.
What is Albumin?
Albumin is a protein synthesized in the liver and makes up approximately 55-65% of total plasma proteins. This means that its action is concentrated in the blood, where it performs versatile but fundamental functions, closely linked to the health of the liver and kidneys. The main one is maintaining the oncotic pressure of blood vessels, meaning it ensures that the liquid part of the blood, the plasma, circulates internally and does not leak into the tissues, causing, for example, swelling and edema. Furthermore, it acts as a transport vehicle for hormones, vitamins, ions (such as calcium), fatty acids, other proteins, and substances important for our nutrition. To a lesser extent, it acts as an alkalinizer in the blood, regulating its pH, as an antioxidant, fighting free radicals, and as an antiseptic and healing agent.
In Which Foods is Albumin Found?
Albumin is present in many foods, especially those of animal origin. The best-known source is egg white: it is thanks to this protein that egg whites have the ability to give structure and stability to many sweet and savory preparations, such as mousses and meringues. It is found in chicken and turkey meat (so much so that it often appears on the surface when preparing a breast), in fish (salmon, but also tuna), in milk and yogurt. Albumin is also found in legumes, such as beans, chickpeas, lentils and soy, but its biological value is lower, as animal proteins do not contain all the essential amino acids like animal proteins.
What Happens if You Have an Albumin Deficiency
Maintaining adequate albumin levels in the blood is important for the body's well-being. Normal values are between 3.5 and 5 g/dL and are monitored with a blood test. When levels fall below this threshold, a condition known as hypoalbuminemia occurs, and the body may begin to show signs of distress. The most common symptoms are water retention, swelling, difficulty healing wounds, and increased susceptibility to infections. Low albumin can have many causes: since it is closely linked to the liver, it is possible that there are liver diseases, kidney problems (which cause it to be lost through urine), or chronic inflammatory diseases. Protein malnutrition is also a factor to take into consideration, for example in those following a vegan diet, for which specific supplements are frequently available.
;Resize,width=767;)
