Caramel odor: Contribution of volatile compounds according to their odor qualities to caramel typicality

Odor of food constitutes one of the main drivers of the consumers' acceptance. Its characterization thus represents a main challenge for the food industry. Gas chromatography/olfactometry (GC/O) constitutes an intersection between physico-chemical and sensory studies by using the human nose as a detector to evaluate the odor properties of volatile compounds. As GC/O does not make possible the evaluation of mixture of odorants, we propose an original approach to evaluate the impact of compounds on the typicality of caramel aroma by considering their odor qualities in mixtures. Indeed, the present study relies on the main hypothesis that the qualitative properties are as important as quantitative one with regard to the typicality. First, previously identified odorant compounds were distributed into eight odor categories using a classification wheel established from our GC/O descriptors. Each category was reconstituted separately and then a Whole Mixture was obtained by mixing all categories in specific proportions and validated by sensory analyses. Second, the impact of specific odor notes on the caramel typicality was studied individually by omission and addition tests and a 2(4) factorial design was built to investigate their interactions in complex mixtures. The caramel typicality results from a complex balance between fruity, vegetal, sharp, nutty and caramel notes arising from the presence of carboxylic acids, aldehydes, oxygenated heterocyclic compounds, ketones and carbocyclic compounds. This study brings new clues to understand the contribution of the caramel volatile compounds to its odor while proposing a promising experimental approach to understand the contribution of volatile compounds to the odor of complex products