Fructose is a simple sugar, also known as a monosaccharide, that is found naturally in many fruits, vegetables, and honey. It is a type of carbohydrate that is similar in chemical structure to glucose, another important monosaccharide.
Fructose has a sweet taste and is often used as a sweetener in processed foods and beverages. It is commonly found in the form of high fructose corn syrup, which is made from corn starch through a process that converts glucose into fructose. High fructose corn syrup is used in many soft drinks, baked goods, and other processed foods as a substitute for sugar.
Fructose is also metabolized differently in the body than other sugars. Unlike glucose, which is primarily metabolized by the liver, fructose is metabolized by the liver and small intestine. This difference in metabolism may have implications for the health effects of consuming high levels of fructose.
While small amounts of fructose from whole foods such as fruits and vegetables are generally considered healthy, high consumption of fructose in the form of added sugars has been linked to increased risk of obesity, type 2 diabetes, and other health problems.
Types
There are two main types of fructose:
- Naturally occurring fructose: This is the fructose that occurs naturally in fruits, vegetables, and honey. In these foods, fructose is often found in combination with other sugars such as glucose and sucrose.
- Commercially produced fructose: This is the fructose that is produced through the hydrolysis of corn starch. Commercial fructose is often used as a sweetener in processed foods and beverages and is commonly found in the form of high-fructose corn syrup (HFCS).
HFCS is available in different concentrations, including:
- HFCS-42: Contains 42% fructose and 58% glucose.
- HFCS-55: Contains 55% fructose and 45% glucose.
- HFCS-90: Contains 90% fructose and 10% glucose.
HFCS-42 is often used in baked goods and other foods where a less sweet taste is desired, while HFCS-55 is commonly used in soft drinks and other sweetened beverages. HFCS-90 is used in some specialized applications, such as in the production of low-calorie and reduced-sugar foods.
It’s worth noting that while fructose is a natural sugar that occurs in many foods, consuming high levels of fructose from added sugars, such as HFCS, has been linked to negative health effects, including obesity, type 2 diabetes, and other health problems. Therefore, it’s important to consume fructose in moderation and as part of a balanced diet.
Production
Fructose is produced commercially through the hydrolysis of corn starch, which is a complex carbohydrate made up of glucose molecules linked together. The process of fructose production involves several steps:
- Corn starch is first treated with an enzyme called alpha-amylase, which breaks down the long chains of glucose molecules into smaller units of glucose.
- The resulting mixture of glucose is then treated with another enzyme called glucose isomerase, which converts some of the glucose molecules into fructose. This process is known as isomerization.
- The mixture is then filtered and the fructose is separated from the glucose using a series of chromatography columns.
- The resulting fructose syrup can then be further processed to produce high-fructose corn syrup (HFCS), which is commonly used as a sweetener in many processed foods and beverages.
HFCS is produced by treating the fructose syrup with another enzyme called glucose syrup solids (GSS), which converts some of the remaining glucose molecules into fructose, resulting in a higher concentration of fructose in the syrup.
Fructose can also be produced from other sources, such as sugar beets and sugarcane, through a similar process of hydrolysis and isomerization. However, corn starch is the most commonly used source of fructose for commercial production due to its abundance and low cost.