Effect of repeated exposure on consumer preferences for sports drinks containing different acidulants
M. Kinnear, H.L. de Kock
Dept. of Food Science, University of Pretoria, South Africa; riette.dekock@up.ac.za
The assumption that brief, once-off laboratory consumer sensory evaluation can predict long-term product perception may not be true. Repeated exposure to specific food stimuli may lead to either an increase or a decrease in acceptance/preference ratings
1. Repeated exposure testing provides an improved reflection of a real-life situation in which consumers repeatedly consume a product over a period of time
2. We predict that time and several exposures to products with subtle differences could change acceptance ratings and/or preference ranking of those products.
Consumers (n=128) ranked five samples of a sports drink according to preference in a sensory laboratory. All five samples were made up using the same drink base but with different acidulants added. The acidulants (citric, malic, tartaric, fumaric and fruitaric acid) were added at equi-sour concentrations. The laboratory ranking exercise was repeated weekly for three weeks. At the end of the first and second laboratory session participants received sports drinks (250 ml each) to drink daily at home until the next laboratory session. Consumers were divided in six experimental groups, each group consuming drinks with a different acidulant added during the home-use phases. One group served as a control group and received no sports drinks to evaluate at home.
At the beginning of the trial the consumers (n=128) significantly preferred (p<0.05) the sports drink with citric acid to the sports drinks with fumaric acid and fruitaric acid, respectively. Repeated exposure resulted in a significant preference for sports drinks with tartaric, fumaric, and fruitaric acids compared to the sports drink with citric acid. A clear shift in preferences occurred. Repeated home-use exposure to the sports drink with citric acid resulted in that group regarding the citric acid sports drink, after three weeks, to be the least preferred (p<0.05) compared to the other samples, while there was no significant preference for a specific sports drink at the beginning of the trial. The consumers that were exposed to fumaric acid showed no significant preferences at first for any of the five sports drink samples. At the end of the trial this groups indicated the sports drink with fumaric acid to be one of the least preferred samples. Home use exposure to the rest of the samples did not result in any clear shift in preferences.
Although repeated exposure resulted in preference ratings to change over time for some samples, exposure to others did not result in clear shifts in preferences.
References:
1. PORCHEROT, C. & ISSANCHOU, S. 1998. Dynamics of liking for flavoured crackers: test of predictive value of a boredom test. Food Quality and Preference 9, 21 – 29.
2. ZANDSTRA, E.H., WEEGELS, M.F., VAN SPROUSEN, A.A. & KLERK, M. Scoring or boring? Predicting boredom through repeated in-home consumption. Food Quality and Preference (in press)