What comes to mind when a flavor is described as refreshing? Some people think of mint’s cooling sensation; others think of acidity or a light, fluid mouthfeel. In a 2009 study, 160 people rated how refreshing model foods felt. They largely agreed on the less refreshing samples but differed over which were the most refreshing.
The study explores how a sensation described by a single word can combine several cues: aroma, taste, cooling, and texture.
Nine gels varying in aroma, cooling, acidity, and thickness
The researchers wanted to identify the characteristics behind the sensation of being refreshing, here understood as a refreshing or invigorating feeling in the mouth. Rather than merely asking about product impressions, they compared combinations of sensations using model foods with different formulations.
The gels had a sugar-and-water base and contained peach or mint flavoring, the cooling agent WS-3, citric acid, and xanthan as a thickener. Flavoring, cooling agent, acid, and thickener were combined at low and high levels to prepare 32 formulations. Preliminary sensory testing identified nine samples with large sensory differences.
Detailed sensory evaluation in the main study was performed by a trained panel of 12 women with an average age of 45, none of whom had taken part in the preliminary tests. They assessed cooling, cooling persistence, sweetness, acidity, bitterness, thickness, astringency, salivation, and other attributes.
Separately, 160 French consumers aged 18–35, comprising 80 women and 80 men, rated how refreshing the nine samples felt. Eligibility was restricted to people who used gum or confectionery for breath refreshing to some extent. Numbered samples were presented in a balanced order. For the trained-panel evaluation, samples were served at 22°C. The study therefore examined sensations created by the formulations, including the cooling agent, rather than differences in refrigeration temperature.
Samples perceived as sweet felt less refreshing
Across the 160 consumers, mean refreshing ratings ranged from approximately 2.8 to 6.6 on a ten-point scale. The two highest-rated samples contained high levels of mint flavoring and cooling agent and a low level of thickener.
The four samples with relatively consistent low ratings were those the trained panel perceived as sweetest. They had low levels of flavoring and cooling agent, but their flavor type, acid content, and thickener content were not uniform.
The study did not progressively reduce the amount of sugar itself. Instead, perceived sweetness varied with combinations of ingredients such as acid. The findings therefore do not provide a direct recipe in which removing a certain amount of sugar necessarily makes a product refreshing.
Three rating patterns among the higher-rated samples
The researchers focused on the five relatively refreshing samples and explored how the 160 consumers’ rating patterns clustered. Three groups emerged.
- Mint-and-cooling group: approximately 36%. These consumers rated mint samples as more refreshing than peach samples. Across samples, cooling was strongly positively associated with refreshing, while sweetness was negatively associated.
- Group giving a low rating to the low-acid sample: approximately 26%. One sample with little citric acid was rated particularly low among the five. The authors interpreted this group as placing importance on acidity. However, the correlation with acidity calculated across the five samples was not itself statistically significant, so the interpretation had less clear correlational support than that for the mint-and-cooling group.
- Low-thickness group: approximately 38%. These consumers rated the three low-thickener samples as more refreshing than the two high-thickener samples. Perceived thickness was significantly negatively associated with refreshing.
These proportions describe the participants in this study, classified using five particular samples. They are not a fixed personality test dividing everyone into three types. The analysis was intended to uncover sensory differences concealed by an overall product average.
What roles might bitterness and food habits play?
In the mint-and-cooling group, more bitter samples were also rated as more refreshing. However, the authors did not attribute the refreshing sensation to bitterness itself. Samples with more cooling agent were also more bitter, making it impossible to separate the influence of these jointly varying attributes.
In this group, 25% used breath-refreshing confectionery several times a day, compared with 12% and 15% in the other two groups. The authors suggest that repeated experiences pairing mint with cooling may have strengthened the association with refreshing.
However, this was not an experiment that changed food habits and followed subsequent ratings. The reverse explanation is also possible: people who already find mint refreshing may use those products more often.
The most refreshing sample was often the favorite
At the end of the test, participants also chose their favorite of the nine samples. For 69%, the favorite was the sample they had rated as most refreshing. In the group interpreted as emphasizing acidity, this agreement was 53%, compared with 74% and 73% in the other two groups.
Refreshing and liking were related, but they were not the same thing. The authors also note that focusing on refreshing throughout the preceding evaluation could have influenced the final preference response.
The study measured an impression felt in the mouth. It did not measure whether body temperature fell, hydration improved, or breath odor decreased.
Summary
Participants agreed relatively well on the sweet-tasting samples that felt less refreshing. Among the more refreshing samples, however, different rating patterns emphasized mint and cooling, more acid, or less thickness. The interpretation of the acidity group remains qualified by its weaker correlational support.
Many participants preferred the sample they found most refreshing, but that relationship also varied between people. Creating a refreshing flavor is not simply a matter of intensifying one aroma or adding acidity. It also requires considering which sensations different people associate with refreshing.
At the time of the study, all authors were affiliated with Nestlé Research Center. Givaudan and CP Kelco supplied ingredients. No separate research-funding section or conflict-of-interest statement was found in the publicly available author manuscript examined.
References
Labbe D, Gilbert F, Antille N, Martin N. Sensory determinants of refreshing. Food Quality and Preference. 2009;20(2):100–109. doi:10.1016/j.foodqual.2007.09.001
