olfaction

olfaction, the sense of smell, contributes noticeably to perceptions of sweetness. Sweet is generally considered to be one of the five principal qualities of the sense of taste—or gustation—along with sour, salty, bitter, and umami (umami refers to the savory taste, associated with glutamates, whether naturally occurring or synthetic). Sweet taste sensations arise primarily from the activation of specialized receptors on cells located in taste buds on the tongue. Yet people also perceive sweet notes in certain odors: in the fragrances of flowers and perfumes, and, significantly, in the aromas of foods. Many food aromas seem distinctly sweet—consider, for instance, the sweet scent of a ripe banana. So how does olfaction contribute to the sweet flavors of foods and beverages?