Does orange juice spoil if left unrefrigerated for one day?

Orange juice contains nutrients and sugars that bacteria easily break down. When left unrefrigerated, bacteria multiply rapidly, causing orange juice to spoil. Additionally, the warm temperature allows for faster chemical reactions that deteriorate the flavors and vitamins in the juice.

Even though pasteurization removes most microorganisms at higher temperatures, once opened, bacteria still find easy access once in contact with air. Keeping orange juice properly refrigerated prevents or slows this from happening and helps retain its flavors and nutritional benefits.