The Science Behind Cooking

Well, we all like eating food. Many of us here like cooking too. In this post I am going to explain what basically happens when our family (or we) "cook" food. And yes don't worry, I am not going to use any kinds of high level physics that might confuse you (well there is no high level physics here that we need to mention).

Basic Food Materials. yum yum..

Well lets now talk about what I mean by "Food". Food is just the term given by us to substances that our digestive system could churn up and produce the much needed energy (or you can say calories) that our body does work with. And by work I mean everything like, walking, breathing, thinking, keeping your body warm e.t.c. 

Now coming to cooking. Cooking is a very good talent that our ancestors passed on to us. In the prehistoric times, when we used to consume food raw, we were not able to break down the food properly so that adequate amount of energy could be derived form it. Like, lets consider meat. Our ancestors used to eat raw meat which they would salvage out of dead animals. Our digestive system was not very strong at that time. Hence it was very hard for us to break down complex carbohydrates and proteins and derive energy form them. 

All this was before fire came into the picture. Fire was "discovered" by our ancestors around 1,000,000 years ago. It was not until 250,000 years ago that our ancestors started using fire to cook. It revolutionized everything. Now we could use that fire in order to predigest food out of our system. Confused by the term pre-digest? Well, its easy, when we expose the food to high amounts of heat (like that inside and above the fire) the complex proteins, that were previously difficult for our digestive system to break down, come already broken down or reduced to digestible compounds. This helps us and helped our ancestors to digest food properly and derive more amounts of energy out of the food. 

Now that we understood what role fire plays in "cooking", lets get back to what is cooking. You could say that cooking is basically pre-digestion performed by us humans in order to make a substance edible and easy to break down by our digestive system. There are many examples of pre-digestion in nature too. Like for e.g. snake venom. When the snake bites its hunt (lets take mouse as an example) it injects lethal doses of its venom. That venom helps dilute the internal organs of the hunt and helps the snake properly digest it without anything left of its hunt except of snake poop (only if they poop). You could say that the snake cooked the mouse before consuming it and hence enabling it to pre-digest the food it ate. In our case we use fire instead of venom.

What happens when we cook food?

Well, it might have been evident to you by now that cooking is when we use fire to break down the unnecessary components of the food to necessary components so that our body is easily able to digest it. Well, I would like to add a little bit more information in this context. Heat is not the only thing we use to cook our food, yes it is the most abundant and favourable method of pre-digesting our food, but there are other ways. One such method of cooking would be cooking by chemical reactions. A good example would be cooking of Ceviche, a traditional South American dish prepared by the acids in lemon or lime juice. Another good example would be that of sushi, or raw fish reacting with glazed rice and vinegar.

What are the advantages of cooking food?

Well, cooking has many more advantages than pre-digestion. Cooking with heat helps us kill many harmful micro-organisms that live inside the raw food. It helps bring out the tastes and odours appealing to us from the food. (the reason behind this is that some complex proteins break down to release simpler proteins and in this process release many "extra" compounds that produce that pleasant olfactory experience).

Now lets enter my favourite zone, the physics behind cooking.

Well, its not very difficult of confusing. And I assure you that it would be very easy to understand.

Now in order to understand the physics behind cooking, lets ask ourselves a question. 

What is heat? And how is it related to cooking?

Heating Food In A BBQ

Well heat is the overall kinetic energy (the energy possessed by the body by virtue of its motion) of the molecules of the food materials. With this we can deduce that when we heat a body the average kinetic energy of the molecules of the body increases. This is synonymous to increase in kinetic energy of the atoms. This results in a more jiggly motion of the atoms, a phenomenon we like calling entropy. Due to this random and vigorous motion of the atoms of the compound, the chemical bonds break causing changes in the chemical composition of the molecules hence breaking them down into simpler substances. Heat also alters the habitable conditions of the micro-organisms and hence killing them, or a more accurate term would be changing their chemical conditions in such a way that it would render them unable to function as determined by their DNA. This would pass the molecules inside their body to pass on to a "dead" or inactive state. As I stated earlier that cooking releases many molecules that produce wonderful olfactory (odour) sensations, this could also be explained by physics. When the molecules are broken down due to increase in entropy/heat, the more simple compounds that are stable at higher temperature are formed. This is synonymous to the fact that compounds always seek stability hence bigger complex compounds are less stable compared to smaller simple compounds (with an exception of few compounds). Hence when they break down, they produce many "side compounds" that our brain, or should I say, our olfactory receptor neurons present in our nasal cavity (nose hole), persieve as smell, i.e. our brain translates it as smell. 

The heating also increases the reactivity of the molecules to each other (who, on normal conditions are un-reactive to each other) which generally forms new compounds changing the overall property (that is the taste, odour, looks etc.) of the food.

There are varied combinations of cooking techniques used by us today which results is some delicious food assortments. We have developed our cooking skills so much that each and every part of the world has diverse cooking styles. But the basic concept remains the same. Always enjoy your food and try thinking why the food is the way it is. So seeya guys. Please 1+ if you liked my post and as always Criticism Is Welcome.

Bon' Appetit