When humans began growing cereals, during the Neolithic Revolution some 10,000 years ago, they gained a powerful source of energy. The use of the starch found in cereals accelerated the development of civilizations, favoring the progress of those populations that consumed it.
Today’s starchy foods represent 25-30% of our recommended diet. In this article we explain what this molecule is so energetic and some of its functions.
What is starch?
Starch is a branched polysaccharide molecule. This means that it is made up of several small glucose molecules, joined by different covalent bonds and placed in chains that diverge at certain points, from which auxiliary chains will sprout.
Starch consists of two types of macromolecules (large molecules formed by the union of smaller molecules), which gives it several of its unique characteristics, such as its insolubility in cold water. These macromolecules are called amylose and amylopectinBoth are long carbohydrates that are joined by plants in different proportions to form starch.
Amylose accounts for 20-25% of starch. It is a molecule with few ramifications and helical (spiral) structure. Linked to amylose is amylopectin, which represents the remaining percentage of starch. Amylopectin is characterized by a tendency to branch into large, long chains, causing each amylopectin molecule contains between 2,000 and 20,000 glucose units.
One of the characteristics of starch molecules is their tendency to crystallize into granules, which can be solubilized in water by increasing its temperature. Its structure in the form of branched chains increases the viscosity of the liquid where it is dissolved, which is why it is commonly used in the kitchen as a thickener.
Where you are
Starch is found in nature acting as an energy reservoir for plants. These generate glucose molecules by means of photosynthesis, which they then join and store as starch in specialised organelles for this task, allowing the subsequent consumption of the excess glucose obtained during photosynthesis.
Most of the starch we consume comes from cereals such as rice, corn or wheat, but can also be found in tubers such as potato. There are many starch-rich plant species specific to certain geographic areas or climates, such as yams or taro.
Of course, this means that the foods derived from these plants will also contain a large amount of starch.Bread or pasta are good examples of this, although the processing necessary to obtain these foods tends to eliminate elements beneficial to our health that were found in the original plants.
Benefits of starchy foods
Eating starchy foods has the main benefit of being a great source of carbohydrateswhich gives us an enormous energy contribution that we can use to function better in our day to day. Their vegetable origin means that starchy foods often have accompanying benefits, such as being rich in vitamin or fibre.
Eating whole grains or starchy foods without industrial processing, such as potatoes with skin, gives us vitamins and fiber in greater quantities, so opting for “whole foods” is often the most positive option for our health compared to consuming more processed foods.
Apart from its high calorie content and ease of obtaining, there are not many known nutritional benefits of starch. It is currently being investigated its role in different processes of the body such as its ability to regulate the metabolism of carbohydrates and lipids, or reduce our appetite. Plus,there are indications that it works as a powerful prebiotic.
Its role as a prebiotic is not yet characterized with certainty, but it is believed that the starch that we are unable to digest would be exploited by our intestinal floracausing different effects on our health. A better intestinal flora facilitates our nutrition and digestion, while making us resistant to gastrointestinal diseases.
In addition, consuming carbohydrates in the form of starch is healthier than consuming simpler forms of glucose, as starch is more complicated for our body to process. This means that some of the starch we consume is not taken advantage of, which favours lower glucose levels compared to the consumption of simpler forms of carbohydrates.
Once assimilated, starch enters our body in the form of small sugar molecules, where it will perform the same function as the rest of glucoseMainly energy intake.
Uses of starch in industry
The structure of the starch molecule allows it from this, through its selective degradation, we can obtain a large number of tremendously useful compounds for different industries.
This means that the multiple molecules of starch amylose and amylopectin can be separated and cut into smaller carbohydrates with different properties that can be used in various industrial processes.
Used for example in the paper industryto strengthen the final product, as the starch network supports the structure of the cellulose fibers, giving higher quality paper. Adhesives of different strengths can also be obtained, it can be used to stiffen clothes after ironing, or as raw material to generate biofuels and bioplastics.
Biofuels and bioplastics applications are good news for the so-called “green economy”.which is trying to reduce its carbon footprint and not rely on petroleum products and fossil fuels. Currently, an example of starch-derived bioplastic could be seen in biodegradable shopping bags.
Its nutritional value is indisputable, but the fact that starch may be the key to the sustainable industries of the future, after being the key to the development of the first cultures in the past, makes starch a faithful ally of human progress.
Bibliographic references
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Nugent, A. P. (2005), Health properties of resistant starch. Nutrition Bulletin, 30: 27-54.
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Revedin, A, et al. (2010). Thirty thousand-year-old evidence of plant food processing. Proceedings of the National Academy of Sciences of the United States of America, 107(44), 18815-18819.