There are three types of carbohydrates: fiber, glucose and starch. While many diets for weight loss suggest limiting the intake of starches and other carbohydrates, researchers are increasingly saying that this is nothing more than a myth. And with proper nutrition, even starchy starchy foods will not settle on the sides with fat. Doctors also said their word about this substance. Moreover, it is also ambiguous. So what is starch, what is the most popular – potato starch, the benefits and harms of which are topics of scientific discussion?
- 1 Biochemical properties
- 2 How it works in the human body
- 3 Functions in the body
- 4 Resistant starch
- 5 Types of resistant starch
- 6 Benefits and harm to the body
- 7 Starch for weight loss
- 8 How to get resistant starch
- 9 Bad starches
- 10 How many do you need?
- 11 Starchy foods and fiber
- 12 Food sources
- 13 Characteristics of popular starchy foods
- 14 Acrylamide in starchy foods
- 15 Combination with other substances and absorption
- 16 Use in industry
Starch (formula – (С6Н10О5) n) is a white granular organic substance that is produced by all green plants.
It is a tasteless powder, insoluble in cold water, alcohol and most other solvents. This substance belongs to the group of polysaccharides. The simplest form of starch is the linear amylose polymer. The branched form is represented by amylopectin. In reaction with water, forms a paste. Starch hydrolysis occurs in the presence of acids and an increase in temperature, resulting in the formation of glucose. Using iodine, it is easy to check the completion of the hydrolysis reaction (blue color will no longer appear).
In green plants, starch is produced from an excess of glucose from photosynthesis. For plants, this substance is a source of energy. Starch in the form of granules is stored in chloroplasts. In some plants, the highest concentration of the substance is found in roots and tubers, in others – in stems, seeds. If the need arises, this substance can disintegrate (under the influence of enzymes and water), creating glucose, which plants use as feed. In the human body, as well as in the bodies of animals, the starch molecule also breaks down into sugars, and they also serve as a source of energy.
How it works in the human body
Carbohydrates are the main source of “fuel” for our body. After the digestive system has converted the food into glucose, the body uses it to activate all the cells and organs. The remains are stored in the liver and muscles. As a universal source of “fuel” is called flour products containing starches and fiber – carbohydrates that promote healthy digestion of food and controlling blood sugar. Such carbohydrate sources break down more slowly than simple ones, provide energy supply and a feeling of satiety between meals for a long time.
Functions in the body
The only role of starch in the human diet is to turn into glucose for more energy.
This process begins at the very moment when starchy food enters the oral cavity. At this stage, the saliva surrounds the starch molecules, acting on them, so a splitting product arises – maltose, a simpler carbohydrate. Then a new substance enters the small intestine, where it undergoes further transformations and turns into glucose. And only after that the body absorbs glucose (intestinal walls), the substance enters the bloodstream and already moves through the vessels throughout the body, supplying each cell with energy.
Meanwhile, the body is not able to use the entire portion of glucose derived from starches in one “sitting”. The excess is stored as glycogen in the tissues of the liver and muscles. And when the body is experiencing a breakdown, glycogen comes to his aid.
Most carbohydrates consumed with food are starches. They are long chains of glucose found in cereals, potatoes, and many other foods. But far from all starches that we eat, the body is able to digest. Sometimes a small portion of starchy food passes through the digestive tract unchanged. In other words, this substance is resistant to digestion. Biologists call this type of starch resistant. And in the body, it functions as soluble fiber.
As many studies show, it is this species that has a very positive effect on health. In particular, it improves insulin sensitivity, lowers blood sugar, reduces appetite and this is far from all the benefits of resistant starches for humans. Resistant starch also helps cleanse the body of “bad” cholesterol and reduces triglycerides.
Types of resistant starch
But not all resistant starches are the same. There are 4 types of this substance:
- type 1 – found in cereals, seeds, legumes;
- type 2 – is in some types of flour, in raw potatoes and green bananas;
- type 3 – is formed when starchy foods, including rice and potatoes, are boiled and then cooled;
- 4 type is the result of chemical reactions.
However, it is important to note that starches of different types can be found in the same food. For example, as bananas ripen, resistant starches become normal. Also, the amount of a stable substance in food is affected by the method of its preparation.
Benefits and harm to the body
In the human body, resistant starch works on the principle of soluble fiber. It passes through the stomach and small intestine in an undigested form, and in the intestine serves as food for beneficial bacteria (intestinal flora). There are hundreds of types of bacteria that affect health, without some of them it would be impossible for the body to function. And resistant starch nourishes these microorganisms. As a result of this interaction, various types of useful compounds are formed – from gases to fatty acids, one of which is butyrate. Starch, thus, feeds beneficial bacteria and indirectly colon cells by increasing the amount of butyrate.
In addition, a resistant substance has several beneficial properties for the intestines. First, it lowers pH, reduces inflammation, and also reduces the risk of colon cancer. Due to the therapeutic effect on the colon, starch can be useful in digestive disorders, including intestinal inflammation, Crohn’s disease, constipation, diverticulosis and diarrhea. Studies have also shown that resistant starch improves the absorption of minerals. Protects the body from toxic substances, preventing intestinal absorption.
But is it a useful resistant starch, as some researchers say? So far, there is no unequivocal answer to this question, as scientific experiments continue. And it is possible that the whole hypothetical miracle of resistant starch may not be confirmed. But the fact that the starch must be part of your diet is definitely.
Resistant starch is important for a healthy metabolism. As some studies have shown, this substance sharpens the body’s sensitivity to insulin, effective for reducing sugar after meals. In addition, it has another unique ability. If breakfast consisted of starchy food, then this substance will prevent a surge in sugar levels after the lunch meal.
The effect of starches on glucose and insulin metabolism never ceases to amaze researchers. Experience has shown that it is sufficient for 4 weeks to take 15-30 g of a substance to increase insulin sensitivity by 33-50 percent. Immunity to this hormone causes diabetes mellitus type 2, obesity, heart disease, and Alzheimer’s disease. By increasing insulin sensitivity and reducing blood sugar levels, many chronic diseases can be avoided.
Meanwhile, the researchers agree that the positive effect of resistant starches on the body depends on individual characteristics.
Starch for weight loss
Compared to regular starch, the resistant one contains half the kilocalories – 2 versus 4 per gram of product. So food containing resistant starch can rightly be considered dietary, while maintaining a feeling of satiety for a long time.
How to get resistant starch
Some foods from the traditional diet are sources of resistant starch. Among the most concentrated are raw, boiled, and then chilled potatoes, green bananas.
Another way to get this substance is ordinary potato flour, a tablespoon of which contains about 8 of a resistant substance and at the same time has almost no carbohydrates, which means that its caloric content is not terrible even for those who are on a diet. Potato starch can be added to prepared foods, mixed with drinks. But do not exceed the 50-gram portion per day, as possible flatulence and discomfort in the stomach. The “starch” program can last for about 2-4 weeks.
Sources of resistant starch can serve as bananas, corn, potatoes, sweet potatoes, barley, oatmeal, lentils, brown rice.
The process of transition from normal to resistant starch is directly dependent on temperature exposure. And what is interesting, in hot starchy dishes there is more than usual substance, in chilled ones – resistant. This means that if you are worried about your figure, then you can not eat mashed potatoes, but without remorse of conscience lean on potato salad.
And on this occasion a few interesting numbers. Chilled potatoes contain slightly more than 3 percent of resistant starch, and this is already 4 times less than usual. Lentils on 75 percent is starch, but the amount of resistant does not exceed 25%.
This may seem strange, but not all starchy foods can serve as sources of starches for humans. This primarily concerns white flour and instant rice. As a result of mechanical processing, these products lose a significant amount of nutrients, including starch. Nutritionists advise avoiding products of this type, since they are not something that will not bring benefits, but they can also cause health problems. Also, do not look at cakes, biscuits, pretzels and cornflakes – you certainly will not find useful starches in these products.
How many do you need?
In order to meet the daily needs of the body in the starch product, it is enough to consume 100 g of whole grains. This is an indicator for women. It is desirable for men to increase the portion to 120-130 g. In general, carbohydrates should be approximately 45-65 percent of the daily diet.
In order to obtain a sufficient amount of a substance, about a third of the diet should be foods containing this substance. Meanwhile, these indicators may vary, for example, during illness.
Doctors say that adults need starch 300-450 g every day. But its use is justified only on the eve of heavy physical exertion or before frequent meals will be impossible. Smaller portions are also helpful – protect the walls of the stomach from digestive acids. But excessive consumption of this substance can cause the formation of fecal stones.
Starchy foods and fiber
Flour products for the production of which whole grains were used, as well as potatoes (especially with peel) are valuable sources of fiber. Also, the combination of starch and dietary fiber is in some fruits, legumes and cereals, in the skin of some vegetables. All of them have a beneficial effect on digestion, and also help to reduce the concentration of cholesterol in the blood.
Starchy foods are a major source of carbohydrates and are important for maintaining a healthy diet. Products such as potatoes, bread, rice, pasta, cereals, according to the advice of nutritionists, should make up a little more than a third of all food. Most of them contain fiber, calcium, iron and many vitamins.
Foods high in starch are primarily legumes (beans, lentils), vegetables (potatoes, zucchini), nuts, cereals and flour from them.
Whole foods rich in starch are still sources of fiber, vitamins and many minerals.
There are several sources that are rich in starch that can be added to your daily diet. Starchy vegetables such as potatoes, corn, peas, zucchini, contain fairly high reserves of the substance. Also important sources are whole grain bread, dark rice, pasta. A portion of flour food can provide the body 15 grams of starch.
Characteristics of popular starchy foods
Especially useful – from wholemeal and rye flour. In both cases there are vitamins of group B, E, fiber, as well as a wide range of useful minerals. White bread also has many nutrients needed by the body, but the amount of fiber in this product is much lower.
Some people refuse bakery products for fear of gaining extra kilos. Meanwhile, it is impossible to completely delete this product from your menu, since along with it a person deprives himself of many useful elements.
By the way, only fresh bread, which is stored at room temperature, is beneficial.
Whole grain cereals are a storehouse of iron, fiber, proteins, vitamins of group B. Among the most useful are cereals made from oats, barley, and erysipelas. Cereal products are an excellent option for preparing a nutritious and healthy breakfast. In addition, do not forget about barley, corn and other grains, which are also considered important for the body.
Rice and food from it is an excellent choice among starchy options. This cereal will provide energy and at the same time practically does not contain fat.
There are different varieties of rice, and all of them are useful for humans, as they contain vitamins, fiber and protein. This product can be consumed both in the form of hot dishes and cold appetizers. But in order for it to be really useful, it is better not to reheat the cooked dish, and if necessary, keep it in the refrigerator between warmings, which will prevent harmful bacteria from multiplying. But under any circumstances, a cooked rice dish cannot be stored for longer than 24 hours. And during reheating for 2 minutes, keep at a temperature of about 70 degrees Celsius (you can above the steam).
It is better to prefer dough made from durum wheat and water. It contains iron and B-group vitamins. Even more useful are wholegrain pasta.
Table of starch content in products
|Flour (wheat, barley)||72|
Acrylamide in starchy foods
Acrylamide is a chemical that can be found in some types of flour products, after frying, grilling or heating at very high temperatures.
Some studies have shown that this substance can be dangerous to humans. Therefore, nutritionists oppose roasting (and especially burning) of starchy foods, such as potatoes, croutons, and root vegetables.
Acrylamide is practically not produced in the process of cooking, steaming or baking in the microwave. And by the way, storing potatoes at very low temperatures increases the concentration of sugar in its composition, which also contributes to the release of a large portion of acrylamide during cooking.
Combination with other substances and absorption
Starch in combination with other nutrients is very demanding. Usually, they interact poorly with other products, and only mix well with each other. For maximum benefit, starchy foods are best combined with raw vegetables in the form of salads. And by the way, the body is easier to digest raw starch than after heat treatment. And also this substance is metabolized faster if there are enough B vitamins in the body.
Use in industry
In industry, there is starch rice, corn, wheat, tapioca, but potato, perhaps, the most popular.
It is produced by grinding the tubers and mixing the pulp with water. Then the pulp is separated from the liquid and dried. In addition, starch is used in brewing and confectionery as a thickener. It is also able to increase the strength of paper used for the manufacture of corrugated cardboard, paper bags, boxes, rubberized paper. In the textile industry – as sizing, giving strength to the threads.
Also in the food industry are actively used amylopectin starch obtained from waxy maize. Used as a thickener in sauces, dressings, fruit and dairy desserts. Unlike potato analogue, this substance is transparent, has no taste, and its unique chemical properties allow repeated freezing and heating of the starchy product.
The presence in the list of ingredients of the product Е1400, Е1412, Е1420 or Е1422 says that modified corn starch was used in the production of this food. It is distinguished from other types by the ability to swell and form gelatinized solutions. In the food industry it is used as an anti-clumping agent to create the necessary texture of sauces, ketchups, yoghurts and dairy desserts. Also used in bakery products.
Tapioca starch is also an ingredient in the food industry. But as a raw material for it, they use not the familiar potatoes or corn, but cassava fruits. By its abilities, this product resembles a potato. It is used as a thickener and a means against the formation of lumps.
Starch is one of the products, about the benefits and harms of which there is no a single opinion. Meanwhile, there is excellent advice that guided people at different times: everything should be in moderation and then food will not be to the detriment. This also applies to starches.