Factors to consider when planning sensory testing with children
Hannah Jilani, Research associate at the University of Bremen at the Institute for Public Health and Nursing Sciences – IPP and at the Leibniz-Institute of Prevention Research and Epidemiology – BIPS, Bremen in Germany
Children are a valuable group of consumer with specific needs and preferences. Therefore, consumer test results from adults cannot be transferred to children. When conducting consumer tests with children many factors have to be taken into account since physical and cognitive abilities of children are less developed than those of adults (Doty RL & Shah M, 2008). Thus, feasibility needs to be considered when planning sensory testing with children.
- Tests have to be easy to understand and quick to conduct as children have short attention spans. The whole test procedure should be short and the way of explaining the test to the children has to motivate them to participate and complete the whole test (Knof et al., 2011).
- The decision making process of children is strongly influenced by adult approval and reaction. Children tend to affirmatively respond to positively phrased questions or change their opinion immediately if asked by an adult (Guinard JX, 2000). A simple question like “Are you sure?” can easily turn a “yes” into a “no”.
- It should also be considered that parents need to give written informed consent for their children, whilst adolescents who are 12 years and older are allowed giving written informed consent. All children should be orally informed and give their oral consent to participate in the study.
- Food intolerances in terms of food allergies and food sensitivities are highly prevalent in Europe. Especially sensitivity to monosodium glutamate and gluten (celiac disease) is widely spread in Europe. Therefore, parents need to be asked regarding particular food allergies of their children before the start of the tests.
- Performing examiners should not use fragrance or perfumed hand cream nor consume cigarettes, coffee, or bubble gum prior to or during the tests. It should be ensured that participating children were neither hungry nor satiated. Ideally, the children had their last meal one hour prior to the test sessions. Moreover, peppermint chewing gum or sweets with a strong taste are not allowed one hour prior to the tests.
- Test environments are most suitable if these are familiar to the children such as a preschool or school environment. In addition, test environments are supposed to be bright, cosy, friendly, and colourful rooms where children would feel comfortable. However, decoration should not be too colourful to avoid distraction. Furthermore, there should be no undesired odours like strong smell from kitchens or disinfectants.
Further, if sensory tests are performed on a multicentre level within one country or even across countries there are more issues to be considered. Procedures for application within the framework of a multicentre study have to provide comparable results. All survey teams need to be trained in a central training session previous to the survey to assure standardised test performance and preparation of test solutions in each survey centre. The training should be attended by at least one representative of each participating survey centre. This central training should include lessons on behaviour, used vocabulary, and phrasing of questions, as well as lessons on handling the equipment for preparation of test solutions and setting up the test environment. Detailed standard operating procedures (SOPs) should be provided to each survey centre.
Even simple test substances, such as sucrose or sodium chloride, can be standardised through a central supply for all test material: Food samples, test substances and equipment for preparation of test-solutions, as well as equipment such as drinking cups can be purchased centrally and shipped to the survey centres. As an example, to avoid anti-caking and flow-regulating agents which are commonly applied by industry, food samples can be purchased centrally without additives and provided to the survey centres pre-packaged and ‘ready-to-use’ for the preparation of the test solutions.
Taking into consideration that tap water quality differs substantially, demineralised water should be used for all test samples and procedures. Accordingly, the selection of appropriate food samples on a multicentre level can also be very challenging. For example, apple juice which is well accepted in most places can be unfamiliar in some other places. Even for common foods the food industry is known to adapt regional food recipes according to the population’s preferences; thus a standardised recipe is needed in all study centres.
Doty RL, & Shah M. (2008). Taste and Smell. In Marshall MH & Janette BB (Eds.), Encyclopedia of Infant and Early Childhood Development (pp. 299-308): San Diego: Academic Press.
Guinard JX. (2000). Sensory and consumer testing with children. Trends Food Sci Technol, 11(8), 273-283.
Knof, K., Lanfer, A., Bildstein, M. O., Buchecker, K., Hilz, H., & Consortium, I. (2011). Development of a method to measure sensory perception in children at the European level. International Journal of Obesity (2005), 35 Suppl 1, S131-136. doi:10.1038/ijo.2011.45
Written by: Hannah Jilani
You can contact me anytime for more information: Jilani@uni-bremen.de