Starch

There are three types of carbohydrates: fiber, glucose and starch. While many weight loss diets suggest limiting your intake of starches and other carbohydrates, researchers are increasingly saying this is nothing but a myth. And with properly thought out nutrition, even starchy flour will not settle with fat on the sides. Doctors also said their word about this substance. And it is also ambiguous. So what is starch, what is the most popular - potato starch, the benefits and harms of which are the topics of scientific discussion?

Biochemical properties

Starch (formula - (C6H10O5)n) is a white granular organic matter 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 a linear polymer of amylose. 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 (no more blue color will appear).

In green plants, starch is produced from excess glucose produced by photosynthesis. For plants, this substance serves as 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 the roots and tubers, in others - in the stems, seeds. If the need arises, this substance can break down (under the influence of enzymes and water), creating glucose, which plants use as a 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 converts food into glucose, the body uses it to activate all cells and organs. The rest is stored in the liver and muscles. As a universal source of "fuel" they call flour products containing starches and fiber - carbohydrates that promote healthy digestion of food and control blood sugar. Such sources of carbohydrates break down more slowly than simple ones, provide long-term energy supplies and a feeling of satiety between meals.

Functions in the body

The only role of starch in the human diet is to be converted to glucose for additional energy.

This process begins as soon as starchy food enters the oral cavity. At this stage, saliva surrounds the starch molecules, acting on them, so there is a cleavage product - maltose, a simpler carbohydrate. Then the 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 obtained from starches in one “sit” at once. The excess is stored as glycogen in the tissues of the liver and muscles. And when the body experiences a breakdown, glycogen comes to its aid.

Resistant starch

Most dietary carbohydrates are starches. They are glucose chains found in cereals, potatoes, and a variety of other foods. But not all the 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 a 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 levels, reduces appetite, and this is not all the benefits of resistant starches for humans. Also, resistant starch helps to cleanse the body of “bad” cholesterol and lowers triglyceride levels.

Types of resistant starches

But not all resistant starches are the same. There are 4 types of this substance:

  • type 1 - found in cereals, seeds, legumes;
  • type 2 - found in some types of flour, raw potatoes and green bananas;
  • type 3 - formed when starchy foods, including rice and potatoes, are boiled and then cooled;
  • type 4 is the result of chemical reactions.

However, it is important to note that different types of starches can occur in the same food. For example, as bananas ripen, resistant starches turn into regular ones. Also, the way it is prepared also affects the amount of a stable substance in food.

Benefits and harms to the body

In the human body, resistant starch works like a soluble fiber. It passes through the stomach and small intestine undigested, and in the intestines serves as food for beneficial bacteria (intestinal flora). There are hundreds of types of bacteria that affect health, without some of which the functioning of the body would not be possible. And resistant starch feeds 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, the resistant substance has several intestinal benefits. First, it lowers pH levels, reduces inflammation, and also lowers the risk of colon cancer. Due to its beneficial effect on the colon, starch may be useful in digestive disorders, including inflammatory bowel disease, Crohn's disease, constipation, diverticulosis and diarrhea. Research has also shown that resistant starch improves mineral absorption. Protects the body from toxic substances by preventing their absorption by the intestines.

But is resistant starch as beneficial as some researchers say? So far, there is no definite answer to this question, as scientific experiments continue. And it is possible that the entire hypothetical miracle of resistant starch may not be confirmed. But the fact that starch must be part of your diet is unequivocal.

Effects on sugar and metabolism

Resistant starch is important for a healthy metabolism. Some studies have shown that this substance increases the body's sensitivity to insulin, effective in reducing sugar after meals. In addition, it has another unique ability. If breakfast consisted of starchy foods, then this substance will prevent a surge in sugar levels after the lunch meal.

The effect of starches on glucose and insulin metabolism continues to amaze researchers. Experience has shown that it is enough to take 15-30 g of the substance for 4 weeks to increase insulin sensitivity by 33-50 percent. Immunity to this hormone occurs in type 2 diabetes mellitus, obesity, cardiac disease, and Alzheimer's disease. By improving insulin sensitivity and lowering blood sugar levels, many chronic diseases can be avoided.

Meanwhile, researchers agree that the positive impact of resistant starches on the body depends on individual characteristics.

Starch for weight loss

Compared to regular starch, resistant starch contains half as many calories - 2 versus 4 per gram of product. So food containing resistant starch can rightfully be considered dietary, while maintaining a feeling of satiety for a long time.

How to get resistant starch

Some foods in the traditional diet are sources of resistant starch. Among the most saturated 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 g of the resistant substance and at the same time has almost no carbohydrates, which means that its calorie content is not terrible even for dieters. Potato starch can be added to prepared foods, mixed with drinks. But do not exceed a 50-gram serving per day, as flatulence and stomach discomfort are possible. The "starching" program can last about 2-4 weeks.

The process of transition from ordinary starch to resistant starch directly depends on the temperature effect. And interestingly, hot starchy foods contain more of the usual substance, while chilled ones contain more of the resistant one. This means that if you are worried about your figure, you can not eat mashed potatoes, but without remorse, lean on potato salad.

And on this occasion, some interesting figures. Chilled potatoes contain slightly more than 3% resistant starch, which is already 4 times less than normal. Lentils are 75% starch, but the amount of resistant no longer exceeds 25%.

Bad Starches

It may seem strange, but not all starchy foods can serve as a source of starches for humans. First of all, this applies to white flour and instant rice. As a result of mechanical processing, these products lose a significant amount of nutrients, including starch. Dietitians advise avoiding these types of foods, as not only are they not beneficial, but they can also cause health problems. Also, do not look at cakes, cookies, pretzels and corn flakes - you definitely will not find healthy starches in these products.

How much do you need?

In order to meet the daily requirement of the body in a starchy product, it is enough to consume 100 g of whole grains. This is an indicator for women. For men, it is advisable to increase the serving to 120-130 g. In general, carbohydrates should be approximately 45-65 percent of the daily diet.

In order to get enough of the substance, about a third of the diet should be foods containing this substance. Meanwhile, these indicators can change, for example, during illnesses.

Doctors say that adults need 300-450 g of starch daily. But its use is justified only on the eve of heavy physical exertion or before frequent meals are not possible. Smaller portions are also beneficial - protect the walls of the stomach from digestive acid. But excessive consumption of this substance can cause constipation and the formation of fecal stones.

Starchy foods and fiber

Flour products made from whole grains and potatoes (especially those with skins) are valuable sources of fiber. Also, a combination of starch and dietary fiber is found in some fruits, legumes and grains, and in the skins of some vegetables. All of them have a beneficial effect on digestion, and also help reduce the concentration of cholesterol in the blood.

Food sources

Starchy foods are the main source of carbohydrates and are important for maintaining a healthy diet. Foods such as potatoes, bread, rice, pasta, cereals, according to the advice of nutritionists, should be 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 their flour.

Whole foods rich in starch are also sources of fiber, vitamins and many minerals.

There are several starch-rich sources that you can incorporate into 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 serving of flour foods can provide the body with 15 grams of starch.

Characteristics of popular starchy foods

Bread

Particularly useful - from wholemeal flour and rye. Both options have B vitamins, E, fiber, as well as a wide range of beneficial minerals. White bread also has many nutrients that the body needs, but the amount of fiber in this product is much lower.

Some people refuse baked goods for fear of gaining extra pounds. Meanwhile, you cannot completely delete this product from your menu, since with it a person deprives himself of many useful elements.

By the way, only fresh bread that is stored at room temperature is healthy.

Cereals

Whole grain cereals are a storehouse of iron, fiber, proteins, B vitamins. Among the most useful are cereals from oats, barley, rye. 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

Rice and rice products are excellent choices for starchy options. This cereal provides energy and is virtually fat free.

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 snacks. But in order for it to be truly useful, it is better not to reheat the cooked dish, and if necessary, store it in the refrigerator between heatings, which will protect against the growth of harmful bacteria. But under any circumstances, the finished rice dish should not be stored for more than 24 hours. And during reheating for 2 minutes, keep at a temperature of about 70 degrees Celsius (you can over steam).

Pasta

It is better to give preference to dough made from durum wheat and water. It contains iron and B vitamins. Even more useful are pasta made from a whole grain base.

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Table of starch content in products
Product Starch (in percent)
Rice 78
Spaghetti 75
Corn flakes 74
Flour ( wheat, barley ) 72
Millet 69
Fresh bread 66
Corn 65
Noodles 65
Buckwheat 64
Wheat 60
Rye 54
Potato chips 53
Peas 45
Rye bread 45
Puff pastry 37
French fries 35
Raw potatoes 15.4
Boiled potatoes 14

Acrylamide in starchy foods

Acrylamide is a chemical 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 harmful to humans. Therefore, nutritionists are against toasting (and especially burning) starchy foods such as potatoes, toast, root vegetables.

Virtually no acrylamide is generated during cooking, steaming, or microwave baking. And by the way, storing potatoes at very low temperatures increases the concentration of sugar in their composition, which also contributes to the release of a large portion of acrylamide during cooking.

Combination with other substances and absorption

Starches in terms of combination with other nutrients are very demanding. Usually they do not interact well with other products and only combine well with each other. For maximum benefit, starchy foods are best paired with raw vegetables in the form of salads. And by the way, the body will more easily digest raw starch than after heat treatment. And also this substance will decompose faster if there are enough B vitamins in the body. perhaps the most popular.

It is obtained by crushing tubers and mixing the pulp with water. Then the pulp is separated from the liquid and dried. In addition, starch is used in brewing, in confectionery products 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 a sizing, which gives strength to the threads.

Amylopectin starch derived from waxy corn is also actively used in the food industry. It is used as a thickener in sauces, dressings, fruit and milk desserts. Unlike the potato counterpart, this substance is transparent, has no aftertaste, and its unique chemical properties allow repeated freezing and heating of the starchy product.

The presence of E1400, E1412, E1420 or E1422 on the ingredients list indicates that modified corn starch was used in the production of this food. It is distinguished from other species by its ability to swell and form gelatinized solutions. In the food industry, it is used as an anti-caking 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 usual potatoes or corn, but cassava fruits. In terms of its abilities, this product resembles a potato one. Used as a thickener and anti-clotting agent.

Starch is one of the products, about the benefits and dangers of which there is no unambiguous opinion yet. Meanwhile, there is excellent advice that people have been guided by at different times: everything should be in moderation and then food will not be harmful. This also applies to starches.

Sources
  1. Baranova E. A. – Potatoes // Potatoes and vegetables. - 2009, No. 9. – P. 19-20
  2. Gulyuk N. G. – Starch and starch products / N. G. Gulyuk. - M.: Book on Demand, 2012 - 430 p.