Fructofin® fructose sweetness

Sweetness Intensity

Crystalline fructose is the sweetest naturally occurring sugar. The sweetness of fructose is 1.2 to 1.8 compared with 1.0 of sucrose. The sweetness of fructose can vary depending on the type of food or beverage in which it is used.

With Fructofin® fructose, the onset of a sweet taste is immediate and it rapidly reaches a sweetness intensity greater than that of sugar (sucrose) and all other bulk sweeteners. This relatively high and quick sweetness of Fructofin® fructose allows for smaller quantities to be used to obtain the desired level of sweetness. Therefore, at 4 kcal per gram and used in smaller quantities, Fructofin® fructose contributes fewer calories to the finished product compared to sucrose, which is  also 4 kcal/g.

Sweetness synergy

Fructofin® fructose is proven to have a sweetness synergy with other bulk and intense sweeteners. For example, a 50/50 blend by weight of fructose and sucrose has a relative sweetness of 128 at 10% dry substance. Equivalent solutions of sucrose and fructose alone have a relative sweetness value of 100 and 117 respectively at the same concentration.

The actual value of sweetness intensity depends on conditions of use such as temperature, pH (see mutarotation) and concentration. As the concentration of fructose is increased, the perceived relative sweetness decreases due to a condition known as sweetness saturation. This means that the sweetener receptor sites on the tongue and palate are fully laden or saturated with molecules and can no longer accept or recognise additional stimuli.

Combinations of fructose and intense sweeteners also behave more synergistically than the same combination with sucrose. For example, a mixture of 3% fructose and 0.188% saccharin (theoretically isosweet with a 5% sucrose solution) will produce a solution equal in sweetness to that of a 7.9% sucrose solution at 5°C. Therefore, less fructose is required to achieve the same sweetness when compared to sucrose.

Mutarotation

In its crystalline state, fructose exists only as D – fructopyranose. When dissolved in water, rapid mutarotation occurs and results in the formation of four and possibly five fructose tautomers. The relative sweetness of the fructose solution is dependent upon the equilibrium between the sweeter pyranose and markedly less sweet furanose tautomers.

This mutarotational equilibrium is influenced mainly by temperature and to a lesser degree by pH. In cold, slightly acidic fructose solutions, mutarotation occurs slowly and the sweeter pyranose tautomers predominate, increasing perceived sweetness.

At higher temperatures, mutarotation occurs rapidly and an increased amount of the less sweet furanose tautomers is formed, resulting in a relative decrease of perceived sweetness.