Various meats can be "cooked" using lemon juice. But how does lemon juice actually "cook" the meat?
Are you talking about things like ceviche?– Cascabel ♦Apr 21, 2012 at 4:45
Let's start with a definition of cooking.
The Oxford English Dictionary defines to cook as:
To prepare or make ready (food); to make fit for eating by due application of heat, as by boiling, baking, roasting, broiling, etc.
However, from a chemical point of view, what happens when you are cooking meat is that you are using heat, amongst other things, to denature the proteins of the meat. Denaturation can also be achieved by other means, such as marinating the meat in an acid, such as citric acid (contain in lemon juice) or acetic acid (contained in vinegar).
You can also use other agents to induce denaturation, but they are not always fit for eating.
However, it is important to understand that from a purely cooking perspective the two things are not the same: "cooking" with lemon (I guess it is fine to use the verb to cook as long as you put it in quotes), gives a completely different result than cooking with heat. This is because other chemical reactions happen during application of heat and because, obviously, you do not end up with an hot product!
Really nice answer, nico. ElendilTheTall has a very good point mentioning the bacteria. Apr 21, 2012 at 8:22
During cooking, heat, amongst causing other things like the Maillard Reaction, denatures (changes the structure of) proteins in meat. Acid is also a denaturant, and so affects the proteins in the same way.
However, a mild acid like lemon juice isn't strong enough to kill bacteria, and it of course only affects the parts of the meat it can reach: consider something like beef carpaccio - when you slice it, you can see that only the surface layer has been denatured. There is also no Maillard Reaction, which is extremely important for both flavour and colour.
2Lemon juice isn't really a mild acid; commercial lemon juice has a typical pH of 2.3 which is actually slightly lower than white vinegar. That's well below the required pickling pH of 4.6, but I think the larger issue is whether or not the acid actually penetrates the interior enough to cook everything; cooking by heat is all based around the internal temperature. I'd probably try acid-cooked steak, but stay away from chicken...– AaronutApr 22, 2012 at 21:14
1Depending on the food, most bacteria will only be on the surface of the food anyway, so penetrating the interior of a shrimp with acid, for instance, shouldn't be necessary from a food safety standpoint. (NOTE: I am not a food-safety expert. I just like to pretend to make educated guesses some times.)– FlimzyApr 23, 2012 at 6:41
@Flimzy I too think that is true, but it is beside ElandilTheTall's point if he/she is correct that lemon juice isn't strong enough acid to kill the li'l critters. Dec 8, 2019 at 20:20
Cooking is only through the application of heat.
Since stomach acids can't kill 100% of pathogens, who is crazy enough to believe lime or lemon juice can?
The question isn't about killing pathogens. It's about how "cooking" with acid works. The use of quotes in the question seems to imply that the OP knows that the meat is not actually being cooked.– Catija ♦Jul 13, 2016 at 15:48