The primary functions of sugar in food products are to provide sweetness and energy.
Our sense of taste can identify four basic tastes: sweet, sour, salty and bitter. The first taste that we encounter (breast milk) is sweet, which may be why a sweet taste is appreciated and interpreted positively.
Our inherent affinity for sweetness may also be explained by the fact that, in nature, sweet products are rarely poisonous, in contrast to many bitter substances.
The only definition of a sweet taste is that it “tastes like sugar”. Sugar has a uniquely clean sweetness that is entirely free from extraneous tastes or aftertastes.
We cannot measure sweetness. In other words, it is a subjective sensation that is transferred via the gustatory nerves in the taste buds on the tongue and passed on to the brain.
Several factors affect the sensation of sweetness. The concentration of sweetener, temperature, pH value, other ingredients, and the sensitivity of the individual. Subjective factors such as appearance and colour can also affect the sensation of taste.
In order for a substance to taste sweet, it must be water-soluble and its concentration must exceed the taste threshold. In the context of food, sweeteners are often present in concentrations well above the threshold value. To specify the intensity of a sweetener, we therefore calculate the substance’s “relative sweetness”.
Relative sweetness is a measure of how sweet a specific substance is in relation to sugar. We compare different concentrations of a sweetener with a reference solution consisting of saccharose (usually 5-10%). Ordinary sugar has a comparison figure of 1.
All natural varieties of sugar have a low relative sweetness compared with high-intensity sweeteners, which are often several hundred times sweeter than ordinary sugar.