Naked Science Forum
Non Life Sciences => Chemistry => Topic started by: thedoc on 23/10/2012 16:45:57
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Hi Chris
We bought 2 kilos of minced beef last weekend from a new butcher. My wife added her usual mix of chopped onion, salt, pepper, cumin, paprika and cinnamon.
When fried as beef burgers, the meat turns white in colour. It also does not taste of "meat" and not the super burgers my wife usually makes.
Do you have any thoughts on this???
Thank you.
Regards
Elias
Asked by Elias Haddad
Visit the webpage for the podcast in which this question is answered. (http://www.thenakedscientists.com/HTML/podcasts/show/20121021/)
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We answered this question on the show...
Ginny - When you think about meat, it’s made of protein and when protein is heated, the shape of it changes. Normally, it’s quite a long molecule. But as it’s heated, it actually shrinks. So, if you imagine cooking a chicken breast, you see that as it cooks, it gets smaller and it also changes colour and this is because of the change in the proteins. We say they denature and that's when they go white and they scrunch up and shrink. Red meat contains an iron rich chemical called myoglobin which also changes its shape when it cooks and changes colour from red when it’s raw to sort of brownish grey when it’s fully cooked.
[img float=right]/forum/copies/RTEmagicC_grilled_meat_01.jpg.jpg[/img]If you're cooking red meat, sometimes you get a lovely brown colour on the outside and that really tasty meat smell that always makes you hungry. This happens because there's something called the maillard reaction. This is a chemical reaction between the amino acids found in the protein and some sugars, and it requires heat to occur. So, the temperature has to get up to about 154 degrees for the maillard reaction to occur and obviously, this is higher than the boiling point of water. So that means that if there's too much water in your meat or if your pan isn’t hot enough, this browning won’t occur. Your meat instead will cook in the water and it will just turn to light brownish grey colour, without you getting any of that lovely, crispy brown outside.