Impact of capsaicin on salt release and salt perception during consumption of salt and salt-capsaicin solutions

The mechanism on how capsaicin could affect salt release in the mouth and its saltiness perception was unknown. This is the first study designed to investigate the impact of capsaicin on salt release in the tongue and correlate with its perception during and after consumption. A simple 1% NaCl solution was used without or with 5 ppm capsaicin as CTR or CAP solution, respectively. Thirty panellists were recruited and trained to score salt and spicy intensity when holding the sample in the mouth for 10 s, then for every 10 s after swallowing till 60 s. Swab analysis was used to investigate the level of salt released after consumption of CTR or CAP solution every 10 s till 60 s. The results indicated that the saltiness rating was significantly reduced by 13% as the result of capsaicin (P < 0.05), which could be due to the dilution effect by extra capsaicin-stimulated saliva. Individual panellists varied on their saltiness and spiciness scores, but there was a positive Pearson’s correlation between saltiness and spiciness scores (P < 0.05), that is, the higher the spiciness ratings, the higher the saltiness ratings. This indicated a potential multimodal interaction between trigeminal and taste sensation.