Study on the mechanism of non-covalent interaction between rose anthocyanin extracts and whey protein isolate under different pH conditions

•The non-covalent interaction between rose anthocyanin extracts (RAEs) and whey protein isolate (WPI) occurred in both systems.•RAEs and WPI had two different and mutually influencing binding sites.•The forces between RAEs/pure anthocyanin (PC) and WPI were both hydrogen bonds and van der Waals forces.•Both RAEs and PC had similar changes in the secondary structure of WPI at different pHs.•The anthocyanins in RAEs may play a key role in the interaction between RAEs and WPI.