Chemical formulas in food

Updated: 3-October-2016.

Ever wondered which molecules are present in your scone when making some? No? I guess I might be one of those ‘strange’ people who does think about food in that way. Although, I am inclined to say that most of us have actually also wondered which molecules are in food (something food chemists love to think about).

Haven’t you thought about fats, carbohydrates, vitamins and proteins in your food? Got you there! These are all chemical components in food. But to do study them properly, you have to know at least how to represent these using so-called chemical formulas.

Do you remember chemistry in high school? Where you had to write down all these complicated formulas and codes with letters, which were supposed to represent molecules? Didn’t see the use of it at the time? We’re going to change that today! Because those codes with letters and numbers (=chemical formulas) can tell us so much about our food! Once you’re able to understand them, you will be able to understand ramblings about fats, carbohydrates, proteins, vitamins and minerals in a far better way.

What again is food chemistry?

Food chemistry applies all that what you learned in chemistry classes on food. Food chemistry is all about studying molecules in food and their reactions. So, to study chemistry properly, you should at least know how to represent and write out those molecules. And that’s why we’re discussing chemical formulas today.

If you’re already familiar with chemical formulas, don’t worry. Just skip through this first part and head down to the last section in which I share a recipe for scones using chemical formulas.

a piece of scone, nearly finished

Molecules & Atoms

Just in case your high school chemistry courses have been a long time ago or you’ve simply forgotten them, let’s start at the beginning. A molecule is a structure build up of atoms. There is a limited numbers of atoms, all of them have been sorted and ordered properly in the periodic table.

Each molecule is build up of at least two atoms. Since molecules can contain a whole range of different number of atoms arranged in different ways, there are loads of possible molecules. Luckily nature does have certain laws for how these atoms arrange themselves.

Some examples of molecules are: sucrose (= standard sugar), as is glucose, a protein, a fatty acid, ascorbic acid (vitamin C) and continue going.

Want to dive a little deeper here or feel that this is going way too fast? Check out my chemistry basics post going through just a little slower.

Most prevalent atoms in food

Food contains so many molecules, that it’s impossible to make a comprehensive list. However, the number of atoms that are present in food is far less (there are simply less atoms). So I will discuss the most prevalent/important ones.

  • Hydrogen (symbol: H) is the smallest atom and it can be found in food very often. It kind of fills up all the left-over spaces.
  • Carbon (symbol: C) is also a very common atom, it is often the backbone of a molecule in food.
  • Oxygen (symbol: O) is often found in foods. Groups with oxygen are often reactive and can enable molecules to connect together for instance.
  • Nitrogen (symnol: N) is mostly present in proteins when it concerns food molecules.

There are of course a lot more atoms which occur in foods. However, with these four you can ‘build’ the main structure of a lot of molecules in food.

scones with jam

Chemical formulas

So, we found that atoms are the building bricks of molecules. By knowing how many of each atom are present in a molecule you can identify and understand a molecule. That’s what chemical formulas are for, they state which atoms and how many of them are present in a molecule. You can write down a chemical formula for each molecule. Some may be very short and simple, others may be so complicated and long that nobody ever writes them down.

A chemical formula always consists of the letters of the atoms. Behind each atom a number is written in subscript indicating how many of these atoms is present in the molecule, for example: H2O. This is the chemical formula for water, it means there are two hydrogen atoms and one oxygen atom in the water molecule. How they sit together with which type of bonds isn’t shown in a chemical formula, it’s a very easy way of representing a molecule.

Another example: ascorbic acid (vitamin C)

Let’s illustrate the principle of chemical formulas using ascorbic acid as an example. Ascorbic acid is another name for vitamin C. It’s an acid, as the name says (read more about acids and bases here). The chemical formula for ascorbic acid is: C6H8O6.

So what does this mean? It means that ascorbic acid contains 6 carbon atoms, 8 hydrogen atoms and 6 oxygen atoms. The formula doesn’t tell you anything about how they’re structured, in a long chain, a circle or whichever other way atoms can be structured. It just tells you which atoms are present.

As you see, ascorbic acid only contains three different atoms. You will see that a lot of chemical structures in food contain mostly these three (or four with nitrogen) atoms.

Other regular chemical formulas for food

To get more familiar with the concept of chemical formulas, here are some more very common food molecules written as a chemical formula:

  • Glucose – C6H12O6
  • Sucrose (standard sugar) – C12H22O11
  • Lactose – C12H22O11
  • Linoleic acid (a fatty acid) – C18H32O2
  • β-carotene (red/orange pigment) – C40H56

In this list you see a problem of chemical formulas. Whereas lactose and sucrose are different molecules, their chemical formula is the same! The difference can be found in the different way the atoms are connected.

Another issue with chemical formulas is that for very complex large molecules it’s hard or even impossible to give a chemical formula. That is a reason proteins aren’t present in this little list, their structures are so complex, describing them with a chemical formula doesn’t give you any useful information.

nearly finished scone

Scone recipe

Let’s get back to those scones I was talking about. Food Science is no fun without food, so let’s apply some of this knowledge we’ve just learned. Below you can find a great recipe for scones (found on Miss Foodwise, a great blogger loving Great Britain). Go through the recipe and look at the ingredients. See, lots of molecules.

Here are some of the main molecules in scones, with their chemical formulas:

  • Water (part of milk and eggs): H2O
  • Sugar: C12H22O11
  • Lactose in milk: C12H22O11
  • Baking soda (part of baking powder): NaHCO3
  • Starch (part of flour): (C6H10O5)n (that’s something new as well, the n indicates it can be a long chain of these groups of molecules)
  • One of the fatty acids in butter (palmitic acid): C16H32O2
  • Salt: NaCl

Ok after this hard learning it’s time for some jumminess, go ahead, make those scones. But think about all the chemical formulas! Leave behind a comment with any other chemical formula you know sits in these scones but isn’t in the list above.

Chemical formulas in food
Author:
Ingredients
  • 450g flour
  • 150g unsalted butter
  • 40g sugar
  • 2 eggs
  • pinch of salt
  • 6 tbsp milk
  • 2 tsp baking powder
Instructions
  1. Mix the salt, flour and baking powder.
  2. Knead in the butter until crumbly.
  3. Stir the sugar through and add the liquids. Mix it all through, don't stir too long, it shouldn't be overworked.
  4. Shape the dough in the desired shapes (I tend to roll out the dough and cut out squares/rectangles).
  5. Brush the top with some egg and place them in the oven at 220C for 15 minutes.

Enjoy!

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