Udisha
Paprika and red chilli powder
Paprika and red chilli powder are very sensitive to heat and light. Keeping them close to the stove dries the natural oils out and the flavour becomes dull, with the smoky taste noticeably out.
Dried oregano
No matter how airtight a jar containing dried oregano is, the steam from the stove get through them. This causes the oregano to lose their aroma, which is its signature.
Garlic and onion powder
If you garlic and onion powder forms clumps easily, the humidity and the heat from the stove is to blame. Extremely moisture sensitive, even a lit bit of moisture from the air can erode their flavour and form stone-hard clumps that render them useless.
Ground cinnamon
Cinnamon dust contains a lot of oils which are volatile to temperature fluctuations. Storing it near the stove makes the oil evaporate and the strong fragrance is completely gone.
Whole peppercorns
Whole spices are usually more resistant to adversities, but whole peppercorns are rich in oil which can go rancid if it is kept close to heat. The spice then turns bitter with a weird aftertaste.