All colors, both synthetic and natural, will eventually fade if exposed to sufficient light. Colorants especially susceptible to light include Red No. 3 and turmeric, while annatto, carmine and some anthocyanins have moderate to good light stability. “Caramel colors have good light stability, plus they absorb UV light, which helps to prevent the degradation of UV-sensitive ingredients in a product, like some nutraceuticals.
Approaches to minimizing light degradation include color encapsulation or emulsions, packaging materials with UV barriers, and shelf-life management. While the color turmeric can fade in days or weeks in the presence of light, an encapsulated form of turmeric can have a shelf life of a year or more.
Red No. 3 is widely used in products like cereals and candies that are packaged in opaque metalized films or other light inhibiting materials.
Anthocyanins are often used in clear-pack beverages with a short turnaround time, as consumers will likely drink the product before noticeable fading or color change occurs.