Could be the fork blades compressing unevenly when turning, causing the rotor to rub on the brake pad momentarily. This isn't uncommon, especially with QR wheels. Try riding the bike and leaning it to one side and then other while maintaining a straight line to see if you can replicate the noise. IMO, the occasional 'ting' when turning or leaning just sort of comes with the territory when using a suspension fork, QRs, and discs.