More importantly, the feeling of pepper is actually not the taste experienced by taste buds, but the burning feeling in the brain caused by the stimulation of the tongue. Capsaicin activates pain receptors in the mouth and skin, so when you take a bite of Chili, your mouth will feel burning immediately, but your nose will not feel it. The unique taste of mustard comes from organic compounds called isothiocyanates. Isothiocyanate is an oily or low melting point solid with a pungent smell.
Allyl isothiocyanate is the reason why mustard oil and horseradish irritate sinuses and cause pungent (burning) sensation. Unlike sour, sweet and bitter, spicy is painful. Pepper and mustard have different compositions. The heat of pepper comes from its active ingredient capsaicin, which is irritating to mammals including humans and can cause burning sensation in the mouth. Because of its low melting point, its temperature is enough to evaporate in the mouth, but because it only stimulates the sinus, the mouth can't interact with it. The gas mustard gas will go up the nasal cavity and stimulate the sinuses.
The above is Xiaobian's detailed explanation of the problem, and I hope it will help you. If you have any questions, you can leave me a message in the comment area. If there is anything wrong, you can also interact with me more. If you like the author, you can also pay attention to me. Your praise is the greatest help to me. Thank you.