Currently, they are still preparing the food at the same facility as Atatürk Airport and taking the food with large trucks every they and store it in the Istanbul Airport facility until the flight is subject to depart. This might be the issue

Also, the chicken seems similar to the grilled chicken that they serve in the lounges.

However, the meal above is definitely not suitable for a Business Class meal. It seems like an Economy Class meal served in a Business Class tray. I've noticed that TK started cost-cutting at Y meals earlier this year ( before the movement ), however, it seems that they are also cutting costs at J.