Factors affecting pink discoloration in annatto-colored pasteurized process cheese

The effects of cooking temperatures, cooling rates, pH, types of emulsifying salts, age of cheese, and sources of colorant were evaluated. Annatto emulsions showed less stability during continuous heating than annatto solutions or suspensions. Increased cooking temperatures resulted in slight decreases in Hunter a and b values, and overall decreases in hue angles. Emulsifying salt blends with increased amounts of sodium citrate resulted in decreased hue angles. Process cheeses made with more than 25% colored cheese showed lower hue angles than those samples made with uncolored cheese only. Whey powder as a source of added solids in process cheese food promoted discoloration, with acid whey resulting in the most pinking.