Green juice was a beverage in the Federation.
In December 2256, Cadet Sylvia Tilly ordered "green juice, extra green" from a food synthesizer after exercising with Michael Burnham. Burnham cancelled her order in favor of a more nutritious alternative, but they soon joined Ash Tyler, who was also drinking a green juice. (DIS: "Lethe")
Since green juice was referenced twice during the same meal, it's possible it was listed on Discovery's menu for the day.