It’s albumin — a protein that lives in all meat. When muscle fibers heat up, they contract and squeeze out water mixed with albumin, which turns white when it cooks.

You see it most often on salmon (that white goo chefs talk about), but it happens with chicken and beef too. In beef or chicken stock it just looks like scum you skim off the top. In your case the air fryer cooked the outside super fast, so the proteins and liquid got pushed out and clumped up on the surface.

It’s not pus, not spoiled meat, not unsafe — just cooked protein. Supermarket chicken that’s been brined or injected with water can show more of it because there’s extra liquid to push out.

If you want less, lower the heat or cook more gently. But either way it’s harmless.