Psychophysical Relationship between Sweetness and Redness in Strawberry-Flavored Drinks.

A consumer-like taste panel of 10 men and women, ages 22-50, evaluated the sweetness, pleasantness and color acceptability of five sweetened, strawberry-red colored beverages, containing 3.2% to 4.8% sucrose, using magnitude estimation. Five intensities of strawberry colors were formulated using increasing volumes of FD&C Red 40 and a constant volume of both FD&C Yellow 6 and imitation strawberry flavoring. Color measurements from the Gardner XL-23 colorimeter and the G. E. Recording Spectrophotometer were converted to L*, a*, b*. Sensory responses were evaluated against the value arctan (a*/b*), representing color intensity, and sucrose concentration, as percent sugar. Sweetness perception increased with increasing sucrose concentration, producing a slope greater than 2.00 (r≥0.87) but produced an exponent less than 1.0 (r<0.91) when evaluated against arctan (a*/b*). Sweetness increased approximately 2 to 12% with increasing color intensity in 4% sucrose solutions. Perceived sweetness was influenced by pleasantness effects and color acceptability. Color 3 samples were rated as the sweetest, most pleasant-tasting drinks and had the most acceptable color. The color-sweetness function was linear over a narrow color range.