I agree, there's some decline. Here's the breakfast "eggs" from my trip from ICN to IST:




It was really disgusting, full of oil. When I complained about it, the "chef" was like "this is how it's done".

I even sent a feedback to TK customer service, and they only said "oh sorry about that".

Granted this was ICN-IST, not departing IST, but still it looks like they don't really care about it anymore. Very sad to see this for an airline that is known for its spectacular food.