McCormick Science Institute

MSI Funded Research: Enhancing consumer liking of lower salt tomato soup over repeated exposure by herb and spice seasonings

Ghawi SK, Rowland I and Methven L


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MSI Team

May 2015-- Researchers in the United Kingdom investigated consumer liking of lower salt tomato soup with herbs and spices. Link to the full text.


In this study, herb and spice blends were used to enhance consumer acceptability of a reduced sodium tomato soup (0.26% w/w). The first aim was to establish whether incorporation of herbs and spices into lower salt tomato soup would give an immediate improvement in the hedonic liking. The second aim was to repeatedly expose the participants to the tomato soup sample over three days and record the change in soup's acceptability, familiarity and consumed volume over exposure time. Finally, the third aim was to compare participant's liking of tomato soup pre- and post- repeated exposure to determine whether repeated exposure improved acceptability and familiarity of the low salt tomato soup with herbs and spices inclusion.


Subjects (n=148) scored their liking of tomato soup samples over five consecutive days. The first and last days were pre-and post-exposure visits where all participants rated three tomato soup samples; standard, low salt and low salt with added herbs and spices. The middle 3 days were the repeated exposure phase where participants were divided into three balanced groups; consuming the standard soup, the low salt soup, or the low salt soup with added herbs and spices.


Reducing salt in the tomato soup led to a significant decline in consumer acceptability, and incorporating herbs and spices did not lead to an immediate enhancement in liking. However, inclusion of herbs and spices enhanced the perception of the salty taste of the low salt soup to the same level as the standard. Repeated exposure to the herbs and spice-modified soup led to a significant increase in the overall liking and liking of flavour, texture and aftertaste of the soup, whereas no changes in liking were observed for the standard and low salt tomato soups over repeated exposure. Moreover, a positive trend in increasing the post-exposure liking of the herbs and spices soup was observed.

The findings suggest that the use of herbs and spices is a useful approach to reduce salt content in foods; however, herbs and spices should be chosen carefully to complement the food as large contrasts in flavour can polarise consumer liking.


Ghawi SK, Rowland I and Methven L. Enhancing consumer liking of low salt tomato soup over repeated exposure by herb and spice seasonings. Appetite. In Press. Available online 28 May 2014. Link to the full text.
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