What foods have DAO enzyme?

Could you elaborate on which foods contain DAO enzyme? I'm particularly interested in understanding which natural sources provide a significant amount of this enzyme, as I've heard it plays a crucial role in histamine metabolism. Are there any specific fruits, vegetables, or other food groups that are known to be rich in DAO? I'd also appreciate any insights you could provide on how DAO enzyme levels may vary depending on the freshness or processing of these foods. Thank you for your assistance in clarifying this matter.