They then searched the man and seized 69 gift cards and a pair of earrings, which had allegedly been stolen.
The man was taken to Parramatta police station and charged with shoplifting, goods in custody, use knife in public place - cause person to fear for safety, and intimidate police officer in execution of duty.
He was refused bail and will appear at Parramatta Local Court today.
Scentre Group, which operates 42 Westfield shopping centres in Australia, launched a review of its security processes earlier this year, after a man killed six people and injured more with a knife at Westfield Bondi Junction on April 13.
The company has since increased the number of security staff and rolled out stab-proof vests for security officers.
Scentre group has been contacted for comment.