Fructose and fructans are two types of carbohydrates that occur in grains and fruits. Both can produce intolerance due to malabsorption inside the body.
Key Areas Covered
1. What is Fructose
– Definition, Structure, Importance
2. What is Fructans
– Definition, Structure, Importance
3. Similarities Between Fructose and Fructans
– Outline of Common Features
4. Difference Between Fructose and Fructans
– Comparison of Key Differences
What is Fructose
Fructose is a monosaccharide that mainly occurs in fruits. D-fructose and L-fructose are the two isomers of fructose and the most predominant isomer is D-fructose in nature. In addition, fructose is the most reactive and water-soluble sugar in comparison to other sugars. Fructose mainly occurs in honey, tree and vine fruits, flowers, berries, and root vegetables. Sugar cane, sugar beets, and corn are the main sources of fructose in industrial production.
Furthermore, the intestine directly absorbs free fructose. In general, the intestine can absorb less than 5 g to 50 g and the values adapt to the dietary fructose intake. However, the small intestine is unable to absorb fructose completely. Then, fructose moves into the large intestine. Colonic flora starts fermenting fructose. This produces gases such as hydrogen and carbon dioxide, which in turn cause bloating, diarrhea, and gastrointestinal pain.
What is Fructans
Fructans are oligosaccharides that are long chains of fructose with one glucose molecule at the end. Therefore, they are fructose polymers. They occur in wheat, some dried fruits, onion, and garlic. However, the digestive system of humans does not contain enzymes for the breakdown of fructans. Therefore, they are indigestible in humans. Subsequently, when fructans reach the large intestine microbes undergo fermentation, producing a small amount of tolerable gas.
Moreover, fructans are fibers that provide a number of health benefits. They are beneficial for coronary heart disease, diabetes, high blood pressure, obesity, and some gastrointestinal disorders. In addition, fibers of fructans prevent constipation and aid in weight loss. Fructans can help to reduce inflammation and enhance immunity.
Similarities Between Fructose and Fructans
- Fructose and fructans are two types of carbohydrates that occur in grains, vegetables, and fruits.
- The body does not contain digestive enzymes to digest both substances.
- Both can produce intolerance in the body due to malabsorption. Abdominal bloating, nausea, pain, gas, flatulence, distension, and diarrhea are the symptoms of intolerance.
Difference Between Fructose and Fructans
Fructose refers to a sugar of the hexose class found especially in honey and fruit, while fructans refer to a type of polymers of fructose present in certain fruits.
Type of Carbohydrate
Moreover, fructose is a monosaccharide while fructans are oligosaccharides.
Fructose occurs in honey and fruits such as apples, watermelon, and pears while fructans occur in wheat, onion, garlic, and some dried fruits.
Importance in Confectionary
Fructose is a component of commercial sweeteners such as tapioca syrup, molasses, honey, and HFCS-90, while fructans are important to increase the fiber content of the products.
Fate in the Gut
Furthermore, fructose is absorbed, adapting to the dietary fructose intake, while fructans are fermented by the beneficial bacteria in the gut.
Fructose contains a lower glycemic index as a commercial sweetener while fructans help to protect against coronary heart disease, diabetes, high blood pressure, and obesity.
In brief, fructose and fructans are two types of carbohydrates that occur in fruits. Fructose is a monosaccharide that occurs in honey and fruits such as watermelon, apples, and pears. It is a component of commercial sweeteners. The glycemic index of fructose is also low. In comparison, fructans are oligosaccharides that occur in wheat, onion, garlic, and some dried fruits. Humans do not have enzymes for the digestion of fructans. But they undergo fermentation with the help of bacteria in the gut. Fructans are fibers beneficial for diabetes, heart disease, high blood pressure, and obesity. Therefore, the main difference between fructose and fructans is their importance.
- Gunnars, Kris. “Is Fructose Bad for You? the Surprising Truth.” Healthline, Healthline Media, 23 Apr. 2018,.
- “What Are Fructans?” Diet Solutions.
- “Beta-D-Fructofuranose” By NEUROtiker – Own work (Public Domain) via Commons Wikimedia
- “Inulin strukturformel” By Florian Fisch – Own Work (Public Domain) via Commons Wikimedia