Flight 136 was diverted to JFK Airport in New York early on July 3, a spokesperson for the U.S. carrier was quoted as saying by The Daily Mail.
Medical staff met the A330 aircraft, which had 277 passengers on board, and provided first aid to 14 passengers and 10 crew members, all of whom declined treatment.
All were provided with hotel rooms and transport, and will be rebooked to continue to their destination.
One frustrated passenger took to social media, asking how the airline was "going to get me to Amsterdam today" after the flight had to divert "because you served passengers ‘contaminated’ food."
The spokesperson added: "Delta teams will immediately work to gather information on how this incident occurred. This is not the service Delta is known for, and we sincerely apologize to our customers for the inconvenience and delay in their travels."
Another Delta airplane made an emergency landing in New York in April after an emergency slide fell off.
No injuries were reported on the Boeing 767, which was carrying 176 passengers.
Airlines serve thousands of meals a day to customers, and such incidents are rare, Henry Harteveldt, a travel consultant and founder of Atmosphere Research Group, said.