COLORIMETRY OF ANTHOCYANIN PIGMENTED PRODUCTS: CHANGES IN PIGMENT COMPOSITION WITH TIME

ABSTRACT Pigment composition and color of a dark red Burgundy‐type wine, strawberry preserves and canned strawberries were followed with time at a storage temperature of 37.7° Celcius. From thin‐layer transreflectance measurements at two pH values, the normal pH of the products, 3.4, and on acidification to < 1.0, the course of anthocyanin degradation and brown polymer formation was followed. Experimental results suggested that on processing and during storage, anthocyanin pigment becomes incorporated into the pH nonresponsive polymeric moiety, resulting in a retardation of pigment degradation and thus, an increase in color stability.