OJ is not so bad. The acidity helps slow the funk. I had carrot juice in a waterbottle once and it went bad by the next morning. The only thing I have found besides water that is safe to leave in a bottle (camelback) is wine. The combination of acidity, around 3.0 to 3.4 pH, and ethanol, 12% to 19% acts as a preservative. I left some grape juice in a water bottle for a week and had fizzy wine for the next ride.