Perception of sugar-acid mixtures in lemon juice drink

Acid was removed from lemon juice by selective adsorption on to a weak-base resin. Four levels each of sucrose and citric acid were combined factorially and dissolved in the low-acid juice, providing sixteen stimulus combinations. Using graphic-rating scales, assessors evaluated the stimuli for intensities of overall flavour, sweetness, and acidity; the relation of each of these intensities to ideal; and general acceptability. The various acceptability responses proved to be internally consistent, and the experiment suggested an optimum sugar-acid blend from the sixteen combinations. Ratings of overall flavour strength followed a compressed pattern in a factorial plot, with increasing concentrations of sugar and acid exerting a diminishingly small effect. In the perception of individual components, sucrose clearly suppressed the perceived intensity of citric acid, but only the highest concentration of acid unequivocally suppressed sweetness. There was a striking similarity between each set of intensity responses and the corresponding ideal-relative responses, suggesting a link between intensity and hedonics.