Monosaccharide of fructose

It is a monosaccharide component of sucrose present in fruits as fruit sugar (laevulose). It is used in beverages, fruit juices, pulps. Fructose is also found in ‘table sugar.’

It provides similar amount of energy as sucrose. Fructose is termed a ‘slow sugar’ as it is metabolized slower than sucrose. In a well-controlled diabetic, the fructose metabolic pathway demonstrates a positive flux towards formation of glycogen from fructose i.e. glycogenesis.

Sources of dietary fructose include agave, the richest natural source of fructose, with 85% of carbohydrate in this form; honey, with approximately 50%; and fruit juices.

Fructose is very sweet and is often made into high fructose corn syrup, used in soft drinks and processed foods. HFCS is made from acid- or amylase-treated corn starch and contains 42–55% fructose. The most popular HFCS formulations used for food applications are the HFCS-42 and HFCS-55. HFCS-55 consists of ~55% fructose and ~45% glucose. HFCS-55 is mainly found in soft drinks and other sweetened beverages.

A 16-ounce bottle of apple juice may have more than 30 grams of fructose and a 20-ounce bottle of soda can have up to 40 grams.

Fructose is associated in epidemiologic studies with greater weight, triglyceride, blood pressure, and insulin resistance levels and in animal and human feeding studies with small dense LDL cholesterol, nonalcoholic fatty liver disease, and greater levels of protein glycation. An increased intake of fructose may cause hypertriglyceridemia, especially in patients with uncontrolled diabetes.

Hereditary fructose intolerance is a very rare genetic disorder. This is when the liver is not able to help the body break down fructose. Symptoms can be more serious. This disorder requires more than just limiting fructose.

Monosaccharide of fructose

Glucose Syrups or High Fructose Syrups

Glucose syrups, also known as corn syrups in the United States, are defined by European Commission (EC) as ‘a refined, concentrated aqueous solution of D(+)-glucose, maltose and other polymers of D-glucose obtained by the controlled partial hydrolysis of starch.

Glucose syrups were first manufactured industrially in the nineteenth century by acid hydrolysis of starch.

Hydrochloric acid was normally used, because sulphuric acid cause haze in syrups due to insoluble sulphates.

The source of starch can vary; in United States corn is widely used, whereas in other part o the world wheat, potato and cassava starch also employed.

The method is non specific, but of conditions are tightly controlled, it is possible to make products with a reasonably consistent carbohydrate profile.

Enzymes are also use to hydrolyze starch to glucose syrups, and these give a greater degree of control over the sugar profile of the resulting syrup.

The availability of commercial isomerizes enzymes in the 1970s, which are capable of converting glucose to fructose, allowed significant development of the production of high-fructose corn syrups with fructose levels of 42% an a sweetness level equivalent to sucrose.

Use of separation technology allowed further refinement of these products to give 55% fructose syrups.

These types of syrups are used extensively in the soft drinks, particularly in the United States.

In soft drinks, glucose, syrups are used to provide sweetness and mouthfeel to products and occasionally specific physiological properties in sports and energy drinks.
Glucose Syrups or High Fructose Syrups

Fructose as Sweetener in Soft Drinks

The term ‘bulk sweeteners’ is used for sugars who normal usage level in beverages places them as the second ingredient, behind carbonated water as the product declaration.

Today the list of commercial food products sweetened entirely with fructose or with a fructose and glucose mixture is long and varied and this includes soft drinks.

Most fructose used to sweetened commercial products is obtained from corn, not squeezed from fruit a process that is impractical for mass production.

Increasing the fructose content reduces viscosity; the level of sweetness increases. High levels of fructose limit the crystallization risk of the syrups, because fructose crystallizes only with difficulty.

Fructose syrups prevent the cap locking of food and pharmaceutical syrups in bottles.

The sweetener in commercial products is usually not fructose alone but a combination of fructose, glucose and other sugar.

In the mid 1980s, 55% high fructose corn syrup was adopted by the carbonated beverage industry and became prominent sweetener in soft drink. It was developed thirty years ago as a cheap alternative to sucrose, or table sugar.

The sweet taste in many soft drinks comes from a mixture of 55% fructose and 43% glucose.

Its cheap to make, tastes sweeter than sugar so manufacturer can use less of it.
Fructose as Sweetener in Soft Drinks

Fructose

Fructose
Fructose can also used as a sugar substitute in crystalline or syrup form.

It is present naturally in many fruits and in honey, but commercially it is manufactured using sucrose as a starting material.

Sucrose is first hydrolyzed to a glucose-fructose mixture.

The monosaccharides glucose and fructose are separated using chromatography and the fructose is then crystallized.

Fructose has some interesting physiological properties. It is monosaccharide sugar with an energy content of 4 kcals/g (17 kJ/g) but due to its increased sweetness can be used at lower levels than sucrose.

Fructose is slowly absorbed and metabolized by the body, independent of insulin production, and does not cause rapid rises in blood glucose after ingestion.

It is therefore, suitable for diabetics and also for use in drinks intended to act as a lower more sustained energy source.

Owing it to limited effect on blood glucose, it is a low glycaemic index sweetener (compared with glucose).

This is an area of increased nutritional interest and may be a stimulus to the greater use of fructose in drinks.

Fructose has also been shown to have a increase satiety effect, compared with other sweeteners.

Mineral absorption (iron and calcium) has also been shown to be positively affected by the incorporation of fructose into the diet.

Chemically, fructose is very active and it readily takes part in maillard reactions, which may cause browning in some products.

It is available in crystalline anhydrous form and also in high concentrations syrups.
Fructose