Sensory Physiology

2. Types of stimuli

These sensations are not taste, but "pain" sensations.

1. Temperature sensitivity

We perceive things as lukewarm if they are around our body temperature @ 36°C up to 43°C.

Above 43°C food is perceived as warm up to a temperature of 52°C

and as hot above 52°C.

The stimulus of hot food triggers a reaction of sweating and increased breathing.

Food is perceived as cold if it has a temperature below 17°C.

Cold food triggers an increased blood flow.

Outside the normal temperature range very cold or very hot food is perceived as painfully uncomfortable.

2. Trigeminal impressions

These sensations are caused by certain chemical properties of food. They play an important role in protecting the mouth from potential tissue damage.

We differentiate different such stimuli into:

Burning heat sensation, caused by contact with chili; perceioved by the capsaicin receptor

Burning cold sensation, caused by mustard oil; perceived by the wasabi receptor

Cooling sensation, caused by mint or eucalyptus; perceived by the menthol receptor

Pungent sensation caused e.g., by onions, vinegar and alcohol

Sharp, stinging sensation caused e.g., by pineapple or cigarette smoke

Sparkling, tingling sensations, caused e.g., by sparkling beverages (CO₂) or Sichuan pepper

Astringent sensations, caused e.g., by pomegranate, red wine or black tea.