Starch is a complex carbohydrate, a polymer of glucose that is widely found in nature and is present in various plants. Depending on the source, starch can have different physical and chemical properties.
The main dietary sources of starch include:
- Potatoes;
- Rice;
- Wheat;
- Corn;
- Legumes.
Starch serves as the primary reserve carbohydrate, providing energy sources for many organisms.
Structure and Properties
Starch is a polymer composed of numerous glucose molecules linked together. Its structure includes two main components: amylose and amylopectin.
- Amylose is a linear polymer that makes up about 20-30% of starch. It is found in sources such as potatoes, corn, and rice.
- Amylopectin is a branched polymer that constitutes 70-80% of starch. It can be found in legumes, oats, and barley.
Health Impact and Diets
There are two types of starch: resistant starch and soluble starch.
Resistant Starch
Resistant starch is not digested in the small intestine, reaching the large intestine unchanged. There, it functions as dietary fiber, contributing to:
- Improved gut health: it serves as a nutrient for beneficial gut flora (prebiotic).
- Reduced appetite: due to slow energy release, it increases feelings of fullness.
- Blood sugar control: it has minimal impact on the glycemic index of foods, which is beneficial for diabetes.
Sources of resistant starch:
- Unripe bananas (not suitable for keto due to high carbohydrate content).
- Potatoes or rice after cooling (not suitable for keto).
- Non-starchy vegetables and nuts (allowed in moderation on keto).
Soluble Starch
Soluble starch is easily digested and quickly raises blood sugar levels, making it less beneficial for health, especially in diabetes or when trying to control weight.
It is found in:
- white bread, pastries, pasta;
- potatoes, corn, rice.
On a keto diet, such foods are excluded due to their high carbohydrate content.
How Starch Changes from One Type to Another
Starch can transition from soluble to resistant through cooking and subsequent cooling.
For example, hot potatoes contain more soluble starch, but upon cooling, some starch becomes resistant.
However, even in this form, potatoes and rice remain high-carbohydrate foods, which is incompatible with keto.
Interesting Facts About Starch
Starch is the primary reserve carbohydrate of plants. It accumulates in roots, tubers, and seeds, providing energy for plant growth and development.
There are two main types of starch. Amylose and amylopectin are the two polymers that make up starch. Amylose has a linear structure, while amylopectin has a branched structure.
Starch can be obtained from various sources. The most common sources are potatoes, corn, wheat, and rice, but starch can also be extracted from tapioca and sorghum.
Starch has many industrial applications. It is used in the production of paper, textiles, adhesives, and even in the pharmaceutical industry.
Starch can be used to create biodegradable packaging. Research shows that starch films could serve as an alternative to plastic packaging.
Starch can be fermented into alcohol. The fermentation process turns starch into alcohol, which is used in the production of beer and whiskey.
Starch was one of the first carbohydrates studied by scientists. In 1833, French chemist Antoine François de Fourcroy first described starch and its properties.
Starch can be used in medicine. In some cases, starch is used to create capsules and coatings for tablets.
Starch can be used in cosmetics. It is present in some cosmetic products as a thickener and stabilizer.
Starch has a long history of use. Archaeological findings show that starch has been used by humans for over 10,000 years.
Starch is used to create pregnancy tests. Some home tests use starch to detect hormone levels in urine.
Starch can be used to produce bioplastics. Research shows that starch polymers can be used to create biodegradable plastic products.
Starch is used in glue production. In some adhesive formulations, starch serves as one of the main components.
Starch helps in the fight against stretch marks. In some cosmetic products, starch is used to improve skin condition.
Substitution options in recipes
Arrowroot starch. In a one-to-one ratio. Arrowroot is gluten-free, forms a clear gel, and works at slightly lower temperatures (≈70 °C). In sauces, remove the pot from the heat immediately after thickening, otherwise the starch will thin out.
