To preserve the vitamin D in eggs, it is important to store them at room temperature rather than in the refrigerator. The method of preparation also has a significant influence on the vitamin D content of eggs.
A new study involving experts from Newcastle University examined the influence of laying time, storage conditions and cooking method on vitamin D concentration in vitamin D-fortified eggs. The results are published in the trade journal “Foods”.
Eggs as a source of vitamin D
By feeding vitamin D in their feed, chickens lay eggs with a higher vitamin D content. However, it’s not just the chickens’ food that seems to have a significant influence on the vitamin D content of the eggs, the researchers report.
To determine other influencing factors, the team compared the effects of storing eggs (in the refrigerator or at room temperature) and five different types of preparation on vitamin D content in the new study.
To do this, the eggs were freeze-dried after storage and cooking and tested for vitamin D3 and 25-hydroxyvitamin D3, the experts explain.
Store eggs at room temperature
“We found that it is better to store the eggs outside the fridge at room temperature, e.g. B. on the kitchen worktop if you want to keep more vitamin D in your eggs,” reports study author Professor Tom Hill in a current press release.
Scramble or poach eggs
It has also become clear that the way the eggs are prepared also influences how much vitamin D they contain. “In terms of preparation method, it is best to scramble or poach to retain most of the vitamins,” adds Professor Hill.
The experts also provide an overview of the vitamin D content of eggs depending on the method of preparation. For this purpose, the vitamin D in the prepared eggs was determined in relation to the original vitamin D content before cooking.
According to the research team, the following values were obtained for eggs that were stored at room temperature before preparation: scrambled eggs 109 percent, microwaved eggs 109 percent, poached 93 percent, hard-boiled 80 percent and finally fried eggs 78 percent.
When comparing normal eggs with enriched eggs, the vitamin D content was 22 to 132 percent higher depending on the cooking method, the researchers added.
“Our previous studies have shown how we can successfully enrich eggs with vitamin D through the chickens’ diet (and) now we know that it is not just the chickens’ diet that can significantly increase the vitamin D content in the egg,” emphasizes the professor Hill. Correct storage and preparation are also crucial. (as)