DIFFERENCE TASTE THRESHOLDS FOR SUCROSE IN WATER AND IN ORANGE JUICE: AN INTERLABORATORY STUDY

Difference taste thresholds, expressed as jnd values or Weberratios, were determined for sucrose in water and in orange juiceat laboratories in Sweden, U.S.A., Poland and Switzerland usinga method of constant stimuli. The following total arithmeticmean values of all 172 individual jnd values were obtained:0.266 and 0.400% sucrose at 2 and 5% sucrose in water, respectively;0.977 and 1.19% sucrose at 1.5 and 3.75% sucrose in orange juice,respectively. The frequency distributions of the individualvalues were asymetrical and showed a large variation among subjects.The results of some additional experiments at 2 and 5% sucrosein orange juice, performed only by the Polish laboratory, arereported also. Significance analyses performed according to one parametricmethod (t-test), using pooled data of groups of subjects, andone non-parametric method (Mann-Whitney's U-test), using individualthreshold values, gave the same conclusion in practically allcases. The data indicated that females had slightly lower average discriminationthresholds than males. There was a significant degree of correlationbetween subjects' discriminatory ability at different concentrationsof sucrose in each of the two media. Few significant differences between the laboratories were foundfor sucrose in water, whereas for sucrose in orange juice thefollowing rank order, from lowest to highest average jnd value,among the laboratories was obtained for both concentrationstested: Poland < U.S.A. < Sweden = Switzerland. Some speculationswere advanced as partial explanation for the differences amongthe laboratories. ^*Formerly Johansson