The taste, odor and hedonic quality of polyglycerols

Abstract

Twenty subjects judged the taste and odor intensity and the taste and odor pleasantness/unpleasantness of five concentrations of sucrose, glycerol, a commercial triglycerol, a synthetic linear diglycerol and a synthetic linear triglycerol. Judgments of intensity were made using the method of magnitude estimation; judgments of pleasantness/unpleasantness were made using a graphic line scale. Only the two linear polyglycerols had appreciable odor intensity. Both were described as having an ‘acrid’ or ‘burnt caramel’ quality. The odor exponent for the linear triglycerol was extremely high (1.44) and may be attributed to its intensely unpleasant quality. Sucrose was characterized solely by sweet taste, glycerol and the commercial triglycerol by sweet and bitter tastes, the linear diglycerol by sweet, bitter and sour tastes, and the linear triglycerol by bitter and sour tastes. The relationships between perceived taste intensity and concentration were well described by power functions, although the slope of the psychophysical function for the linear triglycerol was markedly lower than that for the other compounds. The relative order of taste intensities was: linear triglycerol > sucrose > glycerol = linear diglycerol > commercial triglycerol. Judgments of taste (and odor) pleasantness/unpleasantness showed only sucrose and glycerol to have positive hedonic qualities. All the polyglycerols were judged unpleasant at all concentrations. Differences in the taste and odor characteristics of the commercial and synthetic triglycerols were attributed to the commercial product being a mixture of over 20 compounds. Although the synthetic linear di- and triglycerols are effective in lowering water activity, these data suggest that more purified crystalline forms must be synthesized before they can be used effectively as humectants for intermediate moisture foods.