How Do You Like Your Potatoes?

In carbohydrates like potatoes, rice and beans there are two components.  These are the starch and the cellulose.  When we eat a starchy food like a potato, we are after the glucose that is contained in the starch.  The glucose is in the form of polymers that coil and branch. 

These polymers are what the plant uses for long term energy storage.  Our digestive enzymes, in this case amylases, take the starch and convert it to glucose which our bodies use as our primary fuel source.

When we eat a potato, we are also eating the cellulose.  But we can’t digest the cellulose.  Cellulose is a polymer like starches yet it is very linear. 

Because of this linear, structural arrangement, cellulose polymers make very strong hydrogen bonds which account for the strong fibers that form the walls of plant cells and give plants their structure and strength.

Now, in order for us to get at the starch in our potato we need to break through the stronger cellulose polymer cell walls.  And there are two ways we can do this. 

One way we can do this is by thoroughly chewing our raw potato until it is a pulp.  Another way is by cooking the potato and breaking down the strong hydrogen bonds so that our digestive enzymes will have easy access to the starches when we eat and chew the cooked potato.

So, in the case of the potato that has a strong cellulose structure, it does make a certain amount of sense to cook the food because it’s easier than spending a lot of time chewing the raw potato in order to break down the cellular walls and access the starch.

But there are drawbacks to cooking vegetables, including the potato in our example.  And that has to do with all the delicate vitamins and minerals that are contained in the raw vegetable.  There are also enzymes that come with the raw food that are there to help us break down and digest the food.  The problem with cooking is that the heat largely destroys these enzymes.  This makes it harder to completely break down and digest the food.  More on the drawbacks of cooking later.

For now, you can see that the question of cooking has to do with what you want to accomplish with your food.  And that depends on what kind of food you are talking about.  For example, contrast a carrot or potato, which have very strong cellulose structures, with another plant source like spinach leaves. 

Take an equal volume of a raw potato or carrot, put it in your mouth and see how long it takes you to crush it down into a pulp by chewing on it.  Now take the same amount of spinach leaves and do the same. 

The spinach leaves are going to be much easier for you to chew into a pulp.  That’s because they don’t have nearly the cellulose structure that carrots or potatoes do. 

So with the more delicate, leafy spinach leaves, you’ll be able to have much easier access to the carbohydrate in the spinach that our digestion will convert into glucose for fuel.

Therefore, in the case of potatoes and carrots, it pays to use a method to break down the cellular structure before you eat it.  With softer, leafy vegetables like spinach however, you can eat it raw and break the cellular structure down simply by chewing the food.

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