* Saliva: Saliva is a watery secretion in your mouth that helps to moisten food, break it down (through enzymes like amylase and lipase), and facilitate swallowing. Its watery nature helps to wash away oils and residues from the food you eat.
* Swallowing: The act of swallowing clears food particles and oils from your mouth and throat.
* Enzymatic Breakdown: Although primarily in the stomach and small intestine, some fat digestion begins in the mouth with lingual lipase (secreted from glands at the base of the tongue). While not a complete breakdown, it can start the process of emulsifying fats, making them less "oily."
* Absorption (Limited): While the mouth is primarily for mechanical and initial enzymatic breakdown, some absorption of certain substances (including small amounts of fat) can occur through the oral mucosa.
* Type of Fat: Saturated fats tend to feel more solid or waxy, especially when cooled, which can lead to a more noticeable oily or greasy sensation. Unsaturated fats are liquid at room temperature and might not leave as strong of a greasy feeling.
* Food Composition: The overall composition of the food matters. If a food has a high water content, it might dilute the oily components, making them less noticeable. Also, other ingredients in the food might bind with the fats or help wash them away.
* Individual Variation: Some people naturally produce more saliva than others, or their saliva may have a slightly different composition. This can affect how oily their mouth feels after eating.
* Our perception and expectation: Also our taste receptors might be affected by various food contents. Depending on the condition it might mask oily taste after some food
In summary: Our mouths have a natural cleaning system that involves saliva production, swallowing, and some enzymatic activity. While you may still experience an oily sensation after eating certain foods, this system typically prevents your mouth from feeling consistently oily after every meal.