What are the classifications and applications of resistant starch?

What is resistant starch?
In 1992, the FAO (Food and Agriculture Organization of the United Nations), based on a study by Englyst and the European Resistant Starch Research Collaboration (EURESA), defined it as “non-absorbable starch and degradation products of resistant starch in the small intestine of healthy individuals.” In layman’s terms, resistant starch is not absorbed and enzymatically degraded in the small intestine, but it can undergo a fermentation reaction with volatile fatty acids in the colon of the human gastrointestinal tract. Therefore, resistant starch is also known as anti-enzymatic starch and indigestible starch.
RS is widely found in some fruits and leguminous crops. Food processing such as heat treatment of starch-containing foods, such as cereals and pasta, will produce RS, which is not as easy to maintain high water content as dietary fiber.

Classification of resistant starch
RS1 RS1 are physiologically unacceptable starches, generally whole grains and large starch granules. It refers to those starches that cannot be approached by amylase due to the barrier effect of cell walls or the sequestering effect of proteins. As in partially milled grains and legumes, some of the starch is encased in the cell walls and does not swell and disperse sufficiently in water to be approached by amylase, and is therefore not digestible. After processing and chewing, however, they often become digestible.
RS2 Resistant starch granules, refer to those starches that are naturally resistant to digestion. They are found mainly in raw potatoes, bananas and high straight-chain cornstarch. Their resistance to enzymatic digestion is due to a dense and partially crystalline structure, and their resistance disappears with the completion of pasting.
RS3 regenerated starch refers to the starch that crystallizes during cooling or storage after pasting and is difficult to be broken down by amylase, also known as aged starch. Such as boiled cold potatoes, etc.
RS4 Chemically ModifiedStarch (ChemicallyModifiedStarch) mainly refers to the enzyme-resistant starch portion after physical or chemical denaturation due to the change in the molecular structure of starch and the introduction of some chemical functional groups, such as carboxymethyl starch, crosslinked starch and so on. Meanwhile, it also refers to the enzyme-resistant starch fraction produced by changes in the molecular structure of starch caused by genetic modification during cultivation, such as genetic modification or changes in the molecular structure caused by chemical methods.
Role of resistant starch
Resistant starch optimizes the intestinal environment Resistant starch is not digested by the body’s stomach and small intestine, thus allowing it to enter the large intestine intact. After entering the large intestine, beneficial bacteria in the intestines utilize these starches for fermentation.
Fermentation by beneficial bacteria improves the environment of the intestines, such as lowering the pH of the intestines and producing short-chain fatty acids.
And among these fatty acids, butyrate is abundant. Butyrate is a high-quality source of energy for the cells in the colon, which reduces inflammation and lowers the risk of colorectal cancer. And, these short-chain fatty acids maintain the integrity of the intestinal wall, thereby preventing leaky gut syndrome.
Butyrate doesn’t just stay in the intestines, it also enters the bloodstream and may be useful for other parts of the body as well. Butyrate has a strong anti-inflammatory effect in the immune cells of the human bloodstream.
It is worth proposing that resistant starch increases butyrate content more substantially than other prebiotics.
In addition, in animal studies, resistant starch was found to increase intestinal absorption of calcium, iron and magnesium.
Resistant Starch Lowers Blood Sugar Levels and Increases Insulin Sensitivity Resistant starch plays an important role in the body’s metabolic health.
Insulin resistance is a contributing factor to many chronic inflammatory diseases, including metabolic syndrome, Alzheimer’s disease, obesity and cardiovascular disease.
Many studies have found that resistant starch improves insulin sensitivity, and that resistant starch is also effective in lowering postprandial blood glucose.
In one study, overweight and obese people who consumed 15-30 grams of resistant starch per day had a good increase in insulin sensitivity, equivalent to a 10% reduction in body weight.
In addition, resistant starch has a ‘delayed meal effect’, which means that if you eat a meal rich in resistant starch at lunchtime, your blood glucose will be lowered after dinner.
In fact, when resistant starch is broken down by bacteria in the colon, the glucose it produces is immediately utilized by intestinal bacteria and does not enter the human bloodstream.
Resistant Starch Helps with Weight Loss Resistant starch can have the effect of helping with weight loss in different ways. As we mentioned above, resistant starch lowers blood sugar improves insulin sensitivity, which is helpful for weight loss. In addition, resistant starch increases satiety and reduces fat storage in fat storage cells.
Experiments in mice have shown that resistant starch can reduce weight.
Resistant Starch Helps Treat Allergies Studies have found that long-term intake of resistant starch reduces apoptosis of intestinal cells and maintains the integrity of the intestinal mucosa. Moreover, it reduces the occurrence of leaky gut syndrome and prevents exotoxins from entering the bloodstream.
Allergies and autoimmune diseases are often associated with increased intestinal permeability, and resistant starch may help with this.
Areas of application for resistant starch