Quantitaive and qualitative changes associated with heat treatments in the carotenoid content of paprika oleoresins.

Quantitative changes in the red and yellow carotenoid pigment fractions of four paprika oleoresins were studied at four storage temperatures. At all four temperatures, there was an overall loss of pigmentation, which was more marked with increasing temperature. However, pigmentation loss was not qualitatively uniform. At temperatures below 60 degrees C, the rate of destruction of the yellow pigment fraction was higher than that of the red pigments. Above 60 degrees C, the order of lability of the two fractions was inverted and the red pigment fraction became the more unstable. Thus, treatments above this temperature increase the proportion of yellow pigments. Any heat treatment results in a decrease in the total pigment concentration, with the initial proportion of red and yellow pigments switching in favor of one or the other depending on the temperature used.