Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2019 May 15;9(1):7437.
doi: 10.1038/s41598-019-43944-7.

Oral somatosensatory acuity is related to particle size perception in chocolate

Scott P Breen  1   2 , Nicole M Etter  3 , Gregory R Ziegler  2 , John E Hayes  4   5
Affiliations

Oral somatosensatory acuity is related to particle size perception in chocolate

Scott P Breen et al. Sci Rep. .

Abstract

Texture affects liking or rejection of many foods for clinically relevant populations and the general public. Phenotypic differences in chemosensation are well documented and influence food choices, but oral touch perception is less understood. Here, we used chocolate as a model food to explore texture perception, specifically grittiness perception. In Experiment 1, the Just Noticeable Difference (JND) for particle size in melted chocolate was ~5 μm in a particle size range commonly found in commercial chocolates; as expected, the JND increased with particle size, with a Weber Fraction of ~0.17. In Experiment 2, individual differences in touch perception were explored: detection and discrimination thresholds for oral point pressure were determined with Von Frey Hairs. Discrimination thresholds varied across individuals, allowing us to separate participants into high and low sensitivity groups. Across all participants, two solid commercial chocolates (with particle sizes of 19 and 26 μm; i.e., just above the JND) were successfully discriminated in a forced-choice task. However, this was driven entirely by individuals with better oral acuity: 17 of 20 of more acute individuals correctly identified the grittier chocolate versus 12 of 24 less acute individuals. This suggests phenotypic differences in oral somatosensation can influence texture perception of foods.

PubMed Disclaimer

Conflict of interest statement

N.M.E. has no potential conflicts to report. S.P.B. was a graduate student when the work was performed; he is now employed by Rich Products Corporation, who has no interest or involvement in this work. J.E.H. and G.R.Z. have each received speaking and/or consulting fees from the food industry for work unrelated to this project. Also, the Sensory Evaluation Center at Penn State conducts applied taste tests for the food industry to facilitate experiential learning for students. None of these organizations have had any role in study conception, design or interpretation, or the decision to publish these data.

Figures

Figure 1
Figure 1
Stylized example of a particle size distribution obtained for chocolate using laser diffraction, with several commonly used summary parameters indicated.
Figure 2
Figure 2
Proportion of times each experimentally produced chocolate was judged “grittier than the reference stimulus”. The D90 particle size of the reference for each series is shown in the legend. For context, the gray shaded box indicates the range of particle size for commercially available dark chocolates analyzed via laser diffraction. The commercial products were: (a) Lindt Dark; (b) ChocoLove Strong Dark; (c) Wegmans Supermarkets Dark; (d) Ghirardelli Dark 72%; (e) Cacao Godiva Dark; (f) Hershey’s Special Dark; (g) Ghirardelli Dark 60% Cacao; (h) Scharffen Berger Bittersweet Dark; (i) Cavalier Dark.
Figure 3
Figure 3
Measures of oral somatosensory function collected from young, nominally healthy adults in Experiment 2. In each panel, the x-axis is the nominal pressure applied, and the y-axis is the number of participants. Detection threshold estimates are shown on the left-hand column for the anterior lateral edge of the tongue on the participant’s right (top row), midline center of the tongue tip (middle row) and the anterior lateral edge of the tongue on the participant’s left (bottom row). Discrimination threshold estimates are shown in the right-hand column, at the same locations. The detection thresholds are from 51 participants while the discrimination thresholds are from 47 of the same individuals.
See this image and copyright information in PMC

References

    1. Szczesniak AS. Texture is a sensory property. Food Qual Prefer. 2002;13:215–225. doi: 10.1016/S0950-3293(01)00039-8. - DOI
    1. Hudspeth, A. J., Jessell, T. M., Kandel, E. R., Schwartz, J. H. & Siegelbaum, S. A. Principles of neural science. (McGraw-Hill, Health Professions Division, 2013).
    1. Jeltema M, Beckley J, Vahalik J. Model for understanding consumer textural food choice. Food Sci Nutr. 2015;3:202–212. doi: 10.1002/fsn3.205. - DOI - PMC - PubMed
    1. Bourne, M. Food Texture and Viscosity: Concept and Measurement. 2nd edn, (Academic Press, 2002).
    1. Watt, A. Report: Dark Chocolate leads global market. (Candy Industry, 2015).