Sweetness

Sweetness is one of the five basic tastes detected by taste receptor cells in the tongue and other parts of the oral cavity. It signals the presence of energy-rich nutrients in foods and beverages and is elicited by a variety of chemical compounds, most notably sugars.

In mammals, sweetness is primarily detected by a heterodimeric G-protein–coupled receptor formed by the T1R2 and T1R3 subunits on the apical membrane of taste buds. Activation triggers signal pathways that stimulate nerve fibers connected to the brain, producing the perception of sweetness. Some non-sugar compounds evoke sweetness via alternative mechanisms or act as taste modifiers.

Common sweetening substances include natural sugars such as glucose, fructose, and sucrose; sugar alcohols like sorbitol and xylitol; and synthetic or high-intensity sweeteners such as aspartame, saccharin, acesulfame potassium, and sucralose. Plant-derived sweeteners such as steviol glycosides and thaumatin are also used.

Sweet taste has ecological and nutritional significance, guiding animals toward energy-dense foods. Individual sensitivity to sweetness varies with genetics, age, and prior exposure. Cultural preferences influence preferred sweetness levels in foods and beverages.

Excessive intake of added sugars is linked to dental caries and overweight, prompting public health recommendations to limit sugar consumption. Artificial sweeteners provide little or no energy but remain controversial regarding long-term health effects and appetite regulation.

In culinary contexts, sweetness balances sour, salty, and bitter flavors and is a key feature of baked goods, desserts, and beverages. Some compounds can modify sweetness or sweetness perception, such as taste-modifying proteins like miraculin, which can alter the perception of sour foods.