Does repeated exposure and ad libitum consumption of food and beverages influence consumers’ preferences and sensory perceptions? A systematic review
Conventional sensory analysis methods present some limitations in accurately predicting consumers’ behaviours and product success in the real world. They lack elements of real-life consumption experiences, such as contextual cues and consumption moments (e.g., single-session evaluations with restricted sample sizes). Regarding consumption moments, resorting to repeated exposure (RE) and ad libitum (AL) consumption broadens the dimensions of time and quantity and offers more genuine evaluations of consumption experiences. The absence of a synthesised approach incorporating RE and AL methodologies in existing literature prompted this research, which consisted of a systematic review following the PRISMA methodology. The review aims to assess the impact of these methods on product evaluations and determine the experimental conditions involved. For studies to be included, the following inclusion criteria were defined: evaluation of food products or beverages by consumers (studies only assessing intake or physiological/biochemical responses were not included); RE was only considered when the same group of participants was exposed to the same samples in the same conditions (if experimental conditions differed between exposure session the study was not included); AL studies were only included when consumers performed evaluations on the target food/beverage. AL studies mainly focused on evaluating satiety-related measures and assessing the impact of diet modifications on consumers’ behaviours. Very seldom was AL consumption compared to limited portion sizes in terms of its effect on sensory perception. As for RE, most studies focused on novel foods or foods with lower acceptance (e.g., children exposed to fruits and vegetables), and the exposure was consistently associated with a more positive evaluation of the targeted product. Considering experimental conditions, in most cases, exposure was performed at home, with its effects being evaluated at the laboratory. The duration of exposure varied according to the studies’ goal, ranging from a few sessions up to several months.
Acknowledgements: João Pedro Marques acknowledges Non-Academic Doctoral grant no. 2023.03845.BDANA, funded by the Foundation for Science and Technology (FCT) and supported by Sense Test, Lda. Authors acknowledge support from the Mobilizing Agenda “VIIAFOOD” from the Portuguese PRR (Aviso Nº 02/C05-i01/2022) with No. C644929456-00000040, under the R&D project “HIT-C - High Integration Technology for Consumer Insights”. Authors Marques, J., Rocha, C., Ribeiro, J.C., and Cunha, L.M. are thankful to national funds via FCT through GreenUPorto’s Strategic Projects UIDB/05748/2020 (https://doi.org/10.54499/UIDB/05748/2020) and UIDP/05748/2020.
Publish date 2024-09-07
Author(s) João Pedro Marques, José Carlos Ribeiro, Célia Rocha, Rui Costa Lima, Luís Miguel Cunha
