Impact of sex and age on sensory evaluation of sugar and fat in dairy products.

Ratings of sugar/fat mixtures were examined in eight groups (2 sexes x 4 age categories) of healthy, normal-weight subjects (N = 226). The subjects were tested immediately before and after a standard lunch. Stimuli were 20 semisolid mixtures of soft white cheese or heavy cream containing between 0 and 30 grams of fat per 100 g, and sweetened with 1, 5, 10, 20 or 40% sucrose (wt./wt.). The subjects briefly tasted the samples; they rated stimulus sweetness, fat content and pleasantness, using 9-point scales. Sweetness ratings were a direct function of sucrose concentration. Rating of fat content was more accurate in older subjects. While palatability was nearly synonymous with sugar content in young boys, most groups showed inverted U-shaped preference functions, with optimal sucrose level at 10% in females and 20% in males. Stimuli were rated very slightly but significantly fatter and sweeter after than before lunch; taste preference ratings in the fed condition were sometimes reduced.