Psychophysical Tracking Method to Measure Taste Preferences in Children and Adults

Summary

Sweet taste has powerful hedonic appeal among people of all ages, particularly children. Described herein is a reliable and valid method that can be used to determine the level of sweetness most preferred, making it a valuable psychophysical tool for scientists.

Abstract

The Monell two-series, forced-choice, paired-comparison tracking method provides a reliable measure of sweet taste preferences from childhood to adulthood. The method, which is identical for children, adolescents, and adults, is of short duration (< 15 min), does not rely on sustained attention or place demands on memory (which would yield spurious age differences), and minimizes the impact of language development, making this method amenable to the cognitive limitations of pediatric populations. In this whole-mouth tasting method, subjects are asked to taste (without swallowing) pairs of solutions of different sucrose concentrations and to point to the solution they prefer. Each subsequent pair contains the participant's preceding preferred concentration and an adjacent stimulus concentration. The procedure continues until the subject chooses either a given concentration of sucrose when paired with both a higher and a lower concentration, or the highest or lowest concentration two consecutive times. Subjects are prevented from reaching response criteria on the basis of first or second position bias by the two-series design of the method, which counterbalances the order of solution presentation within each pair between the series (the weaker concentration is presented first in Series 1, second in Series 2). The geometric mean of the two sucrose concentrations chosen in Series 1 and 2 is an estimate of the participant's most preferred level of sucrose. Sucrose preference as determined with this laboratory-based measure has been shown to be associated with preference for sugars in foods and beverages and with taste receptor genotype, family history of alcoholism, and race/ethnicity, as well as depressive symptomatology among pediatric populations. The method has real-world relevance and has been applied to determine most preferred level of other tastes (e.g., salt), making it a valuable psychophysical tool.

Introduction

The sense of taste controls one of the most important decisions we make: whether to eat something or not. From birth, humans show a strong liking for sweet taste¹-it attracts the newborn to mother's milk and signals the presence of calories from nutrient-dense foods (e.g., fruits)². Although this inborn trait confers an advantage for survival in an environment of scarcity, an individual's liking for sweet coupled with a food environment that supplies sugar in abundance has resulted in overconsumption of sweetened foods³. Current estimates suggest that 13.1-17.5% of children's and 11.2-14.5% of adults' total ene....

Protocol

This method has been approved by the Office of Regulatory Affairs at the University of Pennsylvania. For the research studies described herein, informed consent was obtained from each adult and informed assent from each child seven years of age or older.

1. General Considerations

1. Conduct the preference test in a comfortable, private room that ideally has a sink for subjects to expectorate solutions during testing. If a sink is not available, give subjects a cup into which to expectorate.

2. Test Materials

1. Obtain 1-L volumetric flasks, 1-L amber glass bottles, and 100 ml amber glass bottles for the prepa....

Results

Figure 2 contains the tracking grid results from one representative subject. This subject's most preferred level of sucrose, 4.2% w/v, was determined by calculating the geometric mean of the sucrose concentrations chosen in Series 1 (6% w/v) and Series 2 (3% w/v). In cases where the subject only completes one of the series, the geometric mean obviously cannot be calculated. Further analysis can focus on data obtained from Series 1 separately from Series 2¹⁵.

Discussion

The Monell two-series, forced-choice, paired-comparison tracking technique detailed here has been consistently used to determine sweet taste preference among nearly 2,000 racially and ethnically diverse subjects as young as 5 years of age. The preference test, which for children is embedded within the context of a game, is sensitive to the cognitive limitations of children and is a much-needed method to fill the gap in age-appropriate psychophysical research methods for pediatric populations. If completed as described, w.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Sucrose	Spectrum Chemical Mfg Corp	SU103
Distilled water
Corning Pyrex 1000 ml Class A Volumetric Flask	Spectrum Chemical Mfg Corp	988-24433
Boston Round 1000 ml Amber Glass Bottle	Spectrum Chemical Mfg Corp	842-17040
Boston Round 125 ml Amber Glass Bottle	Spectrum Chemical Mfg Corp	842-17031
Heathrow Scientific Multi-Function Stopwatch	Spectrum Chemical Mfg Corp	140-75046
McKesson Medi-Pack Medicine Cups	Amazon	46941200
Solo drinking cups	Amazon	SCCP16RLR