Eggs are a great source of protein. In food preparation, the eggs used may come from chicken, ducks, quail or even fish. Eggs from these sources have different compositions and are affected differently by the different cooking methods. For instance, both chicken eggs and caviar (fish eggs, commonly from the fish sturgeon) contain vitamin B12, an essential vitamin which plays a critical role in ensuring the brain and the nerves in the body work well and also ensures that normal red blood cells are formed. However, caviar contains about 18 times more vitamin B12 than chicken eggs while quail eggs contain 13 times less vitamin B12 than what is in caviar. In spite of this, caviar is unable to withstand high temperature cooking treatments chicken eggs are able to withstand. Also, quail eggs are much smaller than chicken eggs and duck eggs look pretty much like chicken eggs but are bigger than chicken eggs.
Globally, the most common and most consumed type of egg is chicken egg. But their consumption hasn’t gone without passing under the critical lenses of impact on health, safety regarding food-borne diseases, etc.
Nutritional value of egg: the white and the yolk
It is no longer a secret that eggs provide protein. In fact, when all protein sources are compared, the protein from eggs is considered the gold standard. In technical terms, eggs have the highest protein quality; meaning that they have all the essential amino acids in their right amounts in the form in which the body can easily absorb and use for proper growth and development.
It is important to note that egg white (also albumen) contains about 57% the protein in egg. Egg white contains almost no cholesterol, and saturated fats. Also, egg whites are a good source of calcium, copper, manganese, potassium, selenium, folic acid, vitamins B2 and B3.
The yolk of an egg is rich in fat-soluble vitamins; vitamin A, vitamin D, vitamin E and vitamin K. The yellow colour of the yolk of an egg is due to the carotenoids it contains such as lutein (lutein plays a major role in eye health; prevents the formation of cataracts which confer their yellow colour on the yolk. The colour and its intensity is often dependent on the feed the chicken eats. In cases where chicken are fed with feed that has other colour pigments other than yellow, you may observe the effect of that colour pigment on the yolk colour. Egg yolk is where most of the egg’s cholesterol and fats are situated.
Eggs contain other healthful components like choline which protect against liver diseases, promote heart health and is critical for brain development, especially during pregnancy. There is also betaine in eggs which also ensures good heart health.
Eggs, cholesterol and health
On average, an egg yolk contains approximately 271 milligrams of cholesterol while the daily cholesterol requirement for a healthy adult is 300 milligrams, meaning just one egg has enough cholesterol to meet most of your daily requirement. But does the cholesterol in eggs have any influence on total blood cholesterol level? Studies have shown that the cholesterol in eggs does not have any effect on the level of cholesterol in the blood in about 70% of people whereas, the cholesterol in eggs contributes to a mild increase in total blood cholesterol levels. For this reason, the recommendation on restricting intake of eggs cannot be generalized for all people. Also, another study showed that eating 2 eggs per day for 12 weeks increased the amount of good cholesterol in the blood of healthy individuals.
In spite of this, further analysis and studies have shown that though there is no link between egg consumption and heart diseases, regular consumption of eggs may increase the risk of type-2 diabetes and increase risk of heart-related diseases in diabetics. So, it is still important to eat whole eggs (egg white and yolk) in moderation.
For poultry farmers, a study conducted in Italy has shown that supplementing chicken diet with alfafa sprouts and flax seeds reduces the cholesterol and increases the amount of omega-3 fats (healthy fats) in the egg.
Best ways to store eggs
Even with shells on, eggs could be contaminated by microorganisms which slip through the shell’s pores. That is why in certain countries like the US, eggs are sprayed with a chemical sanitizer since they wash the eggs to rid them of the dirt on it after it has been laid. This washing removes the natural coating on the egg (called bloom). This whole process calls for refrigeration of the eggs to keep them safe. However, in several other countries, eggs are kept in the open without the need for any chilling as the eggs still have their natural bloom.
In essence, to store eggs safely, eggs that have been washed have to be refrigerated while those that have not been washed do not need to be chilled to prevent microorganisms from getting in. However, chilling may preserve the freshness of the eggs. Ensure that the pointed part faces down to keep the yolk centred.
Is there a better way to cook eggs?
To boil eggs, put them in a pan and fill it with water to cover the eggs and allow to boil for 1 minute then turn off the heat. Allow to sit for 10 to 12 minutes and strain the hot water and run the eggs under cold water to cool them quickly, remove the shells and enjoy. Cooking eggs this way ensures that both the white and the yolk are cooked hard to ensure any microorganism in the egg are killed and the egg is safe. It is important to boil eggs hard before eating them. This also prevents the formation of the green ring around the yolk which results from overcooking the eggs. You may also fry or poach eggs, though frying may slightly increase the caloric content.
Eggs are filled with essential nutrients and it is still important to eat them in moderation just like every other food.
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