A multisensory approach to study texture and flavour perception in low-fat yogurts

Abstract

Texture and flavour are crucial for low-fat yogurts acceptance and consumer pleasure. Taking into account the dynamic dimension of perception is essential to understand texture-flavour interactions occurring in complex foods and achieve desirable sensory characteristics for consumers. This work aims to study the impact of texture modifications on the perception of flavour in low-fat set-type yogurts enriched with tailored Whey Protein Aggregates (WPA). Two complementary sensory methods were performed: the reference method for static evaluation (Quantitative Descriptive Analysis (QDA)) and an original approach of dynamic evaluation (Temporal Dominance of Sensations (TDS)). Low-fat set style yogurts prepared by adding three concentrations (0.5%, 1.0%, 1.5%) of extra WPA or whey protein isolate (WPI) were flavoured with a model strawberry flavour. WPA were obtained from WPI through a controlled process. Two trained panels (n=15) evaluated texture and flavour properties of the yogurts using respectively QDA and TDS by sensory modality (texture and flavour) with a multi-intake approach. For the same protein concentration, yogurts enriched with WPI were perceived as firm and brittle whereas yogurts enriched with WPA were perceived as viscous and melting. These differences evidenced by the QDA panel were complemented by the TDS results which provided information about the sequence of attributes that were dominant during consumption. Texture differences impacted aroma perception not only by changing the intensity perceived, but also by modifying the sequence of sensory attributes perceived as dominant throughout consumption. Thanks to the complementarity between QDA and TDS it was evidenced that the use of WPA has an impact on both texture and aroma perception, which was confirmed by instrumental measurements. Combination of static and dynamic methods allows a complete characterization of yogurts which is very useful to improve the texture and/or flavour of yogurts during consumption in order to offer a better food experience for consumers