Acquired hedonic and sensory characteristics of odours: Influence of sweet liker and propylthiouracil taster status

Abstract

Repeated pairings of novel food-related odours with sweet tastes can result in enduring changes in sweetness of the odour alone, but have less consistent effects on odour liking. Variation in ability to taste propylthiouracil (PROP) might account for this, since PROP supertasters (ST) have been reported both to experience stronger sweetness intensity and to be more likely to dislike sweetness than do PROP nontasters (NT). Alternatively, individual differences in liking for sweetness may transfer to sweet-paired odours independently of PROP sensitivity. To explore this, evaluations of sucrose, saccharin, and PROP solutions were used to classify 92 volunteers as either sweet likers or dislikers and as PROP ST, NT, or medium tasters (MT). Changes in pleasantness of odours that had been paired with the taste of saccharin increased in sweet likers but decreased in dislikers. Odour sweetness increased regardless of PROP taster or sweet liker status. PROP ST rated saccharin as more bitter than did other taster groups and also showed greater increases in acquired bitterness of the saccharin-paired odour. Overall, these data suggest that individual differences in evaluation of saccharin reliably predict subsequent changes in evaluation of saccharin-paired odours, with hedonic changes corresponding with liking for sweet tastes and sensory changes reflecting differences in sensory quality between PROP taster groups.

Keywords:

• Olfaction
• Taste
• Flavour–flavour learning
• PROP

Acknowledgments

This work was funded by a grant from the UK Biotechnology and Biosciences Research Council (Grant BB/D521622/1). We would like to thank International Flavours and Fragrances and Firmenich for supplying the odours, and Margaret Leitch, Marianne Maalouf, Sarah Robins-Hobden, Emma Bertenshaw, and Khanya Price-Evans for assistance with running the study.