JJP, CDJW and I are about to poach some eggs. A momentous occasion but a necessary part of tonight’s culinary experience (JJP has been watching too much Gordon Ramsay I think!).
This got me thinking about what wonderful food eggs are. Eggs are about 12.5% protein, just over half found in the white part (albumen) which protects the yolk. The yolk itself is an excellent source of protein (16%), vitamins (A, D, E & K) and minerals (Ca, Fe & Mg) although it is also quite high (27%) in unsaturated and saturated fats including cholesterol. The protein has a high biological value (94%) because it is very digestible and contains a high proportion of the amino acids needed by the human body.
Eggs have come in for a bad press over the years, firstly as a source of cholesterol and hence an increased risk of heart disease and secondly as a potential source of salmonella food poisoning. When I was at University in the late 80s, one of my lecturers used to tell us at regular intervals that eggs had no effect on blood cholesterol levels, but it is only very recently that official health advice has supported his view…
“The cholesterol we get from our food – and this includes eggs – has less effect on the amount of cholesterol in our blood than the amount of saturated fat we eat. So, if you are eating a balanced diet you only need to cut down on eggs if you have been told to do so by your GP or dietitian. If your GP has told you to watch your cholesterol levels, your priority should be cutting down on saturated fats.”
As for salmonella, yes, poultry does contain it but then so do you! The important thing is to store and cook your food properly so that you reduce the risk of infection.
When cooked, the egg’s proteins become denatured in an irreversible reaction that sets them hard. Proteins have a particular shape. In the case of enzymes this shape helps them to carry out their jobs as catalysts within living cells. When proteins become denatured they change shape permanently and are no longer able to perform their functions.
I like my eggs slightly runny in the middle; if boiled then soldiers are essential. That has nothing to do with science but I just thought I would let you know.
Questions…
- Name a disease caused by a bacterium and another caused by a virus.
- What is a catalyst?
- Suggest an enzyme found in humans and explain the job it performs.
- What important element is found in amino acids that makes them different from other components of your diet?
Comments