Salt intensity does not affect ad libitum intake of similar pleasant tomato soup

Abstract

The aim of the present study was to investigate the effect of salt intensity on ad libitum intake of tomato soup. Secondly, the perceived salt intensity before and after ad libitum intake of tomato soups with varying saltiness concentrations was assessed. Subjects (n = 48) ate in duplo ad libitum from an individually determined low intense salt (LS) and high intense salt (HS) tomato soup using a self-refilling bowl. Before and after ad libitum intake, LS and HS soups were sampled and judged on salt intensity and pleasantness. The results showed no difference in intake between the two soups (LS 375 ± 172 g vs HS 388 ± 154 g). After intake of the LS soup, salt intensity for the HS soup was perceived as more intense salt and the pleasantness of HS soup decreased significantly more than the pleasantness of the just eaten LS soup (−22 ± 23 vs −9 ± 22 P < 0.05). After intake of the HS soup, the LS soup was perceived as less intense salt and the pleasantness of LS soup tended to be more decreased than the pleasantness of the just eaten HS soup (−20 ± 24 vs −14 ± 21 P = 0.2) In conclusion, we did not find an effect of salt intensity on ad libitum intake of tomato soup. Unexpectedly, the decrease in pleasantness for the ‘uneaten’ soup was more than for the just eaten soup, which is opposite to the “sensory specific satiety” effect. Subjects may obtain a new “reference point” of salt intensity after eaten a LS or HS soup. Therefore, they find the LS soup after intake of the HS soup too bland and the HS soup after intake of the LS soup much too salty. This could explain the higher decrease in pleasantness of the uneaten soup instead of the eaten soup.