FACTORS AFFECTING LIGHT-INDUCED PINK DISCOLORATION OF ANNATTO-COLORED CHEESE

The effects of light type, exposure and intensity, storage temperature, pH, fat content, and age and source of colorant were evaluated on stability of annatto colorants in cheese. Exposure to cool white fluorescent lighting resulted in a decrease in Hunter b values and hue throughout storage. Decreased temperature reduced the loss of a and b values after 2 days of light exposure. As time of exposure increased, reduction of a and b also increased. As pH changed from 5.4 to 4.8, b values were reduced at a faster rate than a values resulting in an intense pink color. Commercial cheese colorants extracted from annatto seeds were variable in color stability.