Stability of Color in'Concord'Grape Juice and Expression of Color

The experiment was designed to determine the influence of chemical additives, ascorbic acid and storage time on‘Concord’grape juice color. Adding low concentrations of CaSO₄ and SnCl₂ increased retention of color as measured by Color Difference Meter (CDM) L, a and b values and by color expression a/L, aL and ab/L. Rapid color changes occurred during storage after 3 months except in juice with added CaSO₄ and SnCl₂. Ascorbic acid fortification accelerated color loss in some of the treatments. The highest correlations between sensory quality and instrumental color were those between sensory ratings for browning, flavor and hue and CDM L values, anthocyanins and absorbancíes at 535/430 nm.