Nelson Cheung and his wife Winnie, 57, had been driving along the Caddy Road, near Randalstown, on Wednesday when their car was forced off the road.
The couple, from the Ballymena area, were attacked and had money stolen. Mr Cheung died from stab wounds.
Police have renewed their appeal for information. A 30-year-old man is being questioned about the murder.
A 31-year-old woman and a 29-year-old man who were arrested on Thursday have been released unconditionally.
Det Ch Insp Eamonn Corrigan said: "Mr Cheung was a well-liked and well-known man who ran a Chinese restaurant in Randalstown."
He said that while Mrs Cheung had been discharged from hospital, she was "understandably anguished following the murder of her husband".
After their car was forced off the road by two other vehicles, Mrs Cheung had managed to raise the alarm at a nearby house just after midnight on Thursday.
When police arrived at the scene a short time later, they discovered Mr Cheung's body. Police have said a hate crime is not suspected.
The detective said: "I would appeal for information from the public, specifically anyone who saw vehicles moving along Caddy Road between 11:30pm on Wednesday night and 1pm on Thursday morning.
"I am also interested in speaking with anyone who may have noticed a black Seat Toledo car, registration number OE62 FRF, in the Randalstown area from around 9pm to midnight on Wednesday 7 January."
The Caddy Road has now been reopened following the murder.
Police have released the name of a 65-year-old Chinese restaurant owner murdered in County Antrim.