Lately I’ve been getting a lot of emails wanting to know what resistant starch is and whether it’s possible to get flatulence from resistant starch.
What is resistant starch?
We know strength. We use it as a powder to thicken sauces or know it as an ominous ingredient in pasta, potatoes or rice that supposedly makes us fat. It is the starch that makes risotto, for example, so beautifully creamy. Why? We’ll clarify that in a moment.
Starch (lat. amylum) consists of two glucose chains, i.e. two polysaccharides. They are called amylose and amylopectin and are each made up of around 50,000 sugars. Amylose makes up around 10 to 30 percent of naturally occurring starch, amylopectin 70 to 90 percent. If you add water to starch and heat it, it swells and multiplies in volume(with funny effects…). The starch then gelatinizes and becomes sticky. Such processes help sauces, for example, to thicken and become creamy.
Our pancreas produces starch-degrading enzymes called amylases. This means that starch is largely broken down into individual sugars (glucose) in the small intestine and these sugars are then absorbed into the body. They are an important source of energy in our diet. And yes, a lot of starch means a lot of glucose, so we know why starch is notorious for being fattening.
However, starch can also be resistant, i.e. it cannot be broken down. So they do not turn into glucose and are therefore not fattening. Undegraded starch that arrives undigested in the large intestine is called “resistant starch”.
Three types of resistance
But not all resistance is the same. There are three types of resistant starch. The first type is starch, which is enclosed in the cells of our food, making it difficult or impossible for digestive enzymes to access. We find this, for example, in whole grains or other seeds. In order to digest them, we have to chew these grains well and break them down mechanically.
The second type has a form whose molecular structure makes it impossible for the enzymes to break it down. This type is usually found in raw foods such as raw or still green bananas, but also in some legumes. However, these starch molecules can be made digestible by heating. This means that a cooked potato has the same amount of starch as a raw potato, but we can use it as an energy source. And it tastes better…
The third is called retrograded strength. And that’s the kind of thing we’re usually talking about when we read about resistant starch. It is produced during the slow (!) cooling of heated, starchy foods. Slowly means over several hours. When the bound sauce or cooked rice cools down again, some of the starch molecules are redeposited. Crystalline areas are formed. These areas or the resulting starch molecules cannot be broken down by the enzymes in the intestine. So starch is suddenly no longer a fattening agent.
But be careful: if the cold food is reheated, the above-mentioned resistant amylose remains resistant. However, resistant amylopectin loses its resistance again from approx. 50°C. And remember, this type makes up the majority of the starch in our food. Unfortunately, it is once again a fattening food.
But why is all this relevant?
The resistant starch therefore enters the large intestine…