Understanding the role cross-modal sensory interactions play in food acceptability in younger and older consumers

Chemosensory acuity decreases with increasing chronological age, although not all senses decrease in acuity to the same extent. Through an improved understanding of the perceptual capabilities of the residual senses and the relative contribution each makes to an acceptance decision, it is possible to understand the sensory limitations of older consumers and devise compensation strategies to combat chemosensory loss. A commercially available orange juice was modified using aspartame, orange cells and capsaicin to provide varied levels of "sweetness", "pulpiness" and "prickle/heat". Perceptual differences for each attribute were established through studying concentration response functions using psychophysical techniques with a panel (N = 20) of objective sensory assessors. These results were used to produce 18 orange juice samples, using a 3 x 3 x 2 factorial design of variations to the three stimuli, which were assessed using descriptive analysis by a panel (N = 6) of trained sensory assessors. The resulting perceptual map of the product differences was used to select eight orange juice samples varied in "sweetness" (50, 400 ppm), "pulpiness" (0, 10% w/v) and "prickle" (0, 0.02 ppm) for acceptability testing with younger (N = 48) and older (N = 52) consumers. All participants were first tested for their sensitivity to sensory stimuli (taste, smell, irritation and texture perception). Participants were then requested to provide an overall measure of liking using a labelled affective magnitude scale. The acceptance measures -showed differences between the two age groups as the younger assessors based their liking decisions on the predominant chemosensory attributes while the older assessors were more heterogeneous with some incorporating textural influences into their liking decision. To understand the attributes driving the liking the older assessors were divided into three groups based on their distribution on the preference map and partial least squares regression (PLS) was used to relate the sensory profile of the juices to the liking measures. Comparison of the groups revealed that the younger assessors selected against high aspartame and capsaicin levels, while the older assessors were more heterogeneous in their liking. Some of the older consumers that preferred higher levels of sensory stimulation ("sweetness" and "prickle") tended to have lower sensitivity than the other groups across a range of sensitivity measures. The results show the diverse nature of the older consumer segment and demonstrate a possible role for increased textural and irritant sensation in compensating for chemosensory loss. (C) 2004 Elsevier Ltd. All rights reserved.