oleogustus

Oleogustus is the proposed basic taste corresponding to fatty acids, particularly long-chain fatty acids, detected by taste cells in the mouth. The term, derived from “oleo” (oil, fat) and “gustus” (taste), is used to describe the possibility of a distinct gustatory modality for fats, separate from the traditional tastes and from olfactory or textural cues. The status of oleogustus as a true basic taste remains a topic of ongoing research and debate.

Biological basis: Several fatty-acid receptor mechanisms have been implicated in oral fat detection. CD36, a fatty-acid transporter/receptor, is expressed on taste receptor cells and has been linked to fatty-acid detection in humans and animals. Additional receptors, such as GPR120 (FFAR4) and GPR40 (FFAR1), are also expressed in taste buds and may contribute to fatty-acid signaling. The relative contributions of gustatory (taste bud) versus chemesthetic routes (trigeminal fibers) are still being clarified.

Evidence and interpretation: Behavioral studies show that people can perceive differences in fatty-acid concentrations and that fat-related cues can influence preferences and intake. Some studies report associations between fat-taste sensitivity and dietary fat consumption or body adiposity, though findings are not consistent across populations. Cross-cultural differences and methodological variations in testing fatty-acid taste complicate interpretation.

Controversy and status: Not all researchers accept oleogustus as a distinct basic taste; critics emphasize that fat perception can arise from illusory texture, aroma, or trigeminal sensations related to pungency or irritation. The concept remains debated, with ongoing work aimed at standardizing measures of fatty-acid taste sensitivity and clarifying the neurobiological substrates.