Why does freshly squeezed orange juice appear lighter in color at different times of the year while the appearance of the carton juice is consistent?
The color of orange juice depends on the variety of orange used and when in the season it was harvested. The earliest juice is virtually clear, while late-harvest juice has that familiar deep-orange color of carton juice. Though color doesn’t necessarily have anything to do with taste or sweetness, manufacturers of carton juice (like Tropicana) try to ensure their juice always looks the same. They squeeze and store juice from the early, mid-, and late-season harvests in super-chilled vats that preserve flavor, then mix the juices together to make them consistent from carton to carton. To further enhance color, manufacturers add up to 10 percent vividly colored mandarin orange juice as well as pigment from orange peels.
When you buy freshly squeezed orange juice, you’re getting the juice direct from harvesting, with no mixing and matching, so the color may change as the season goes on. You may notice another difference with freshly squeezed juice: It tends to separate, while carton juice doesn’t. Carton juice is pasteurized at a high temperature (over 190 degrees) to extend shelf life and to deactivate an enzyme called pectinesterase that causes the juice to separate upon standing. Freshly squeezed juice is “flash pasteurized” at a lower temperature that doesn’t impact this enzyme.
In a nutshell: Any variance in a natural, minimally processed product like freshly squeezed orange juice is, well, natural.