Review unravels importance of texture for aroma release and perception
The research, published in Flavour and Fragrance Journal, explained that the acceptability of food products by consumers “is governed to a considerable extent by their organoleptic properties, and mostly by aroma perception.”
“As food is consumed, the overall sensory perception that includes texture, taste and aroma occurs simultaneously and/or consecutively and is then integrated by the brain to produce a global and complex sensation,” said the authors, led by Helene Laboure, from the University of Burgundy, France.
The authors said that in order to control aroma perception, knowledge of the main factors which influence in-mouth aroma release “is of major importance.”
“Indeed, two mechanisms (physicochemical and cognitive) may be pertinent to explaining the influence of structural modifications on aroma perception,” added Laboure and colleagues.
“In order to be perceived, aroma compounds need to be released in the mouth during food breakdown and then transferred into the nasal cavity to reach the olfactory receptors,” said the authors.
They explained that the amount of aroma compounds released during food consumption depends on the composition of the food matrix, its structure, and also on masticatory (chewing) behaviour – which can lead to different modes of food breakdown.
Laboure and co-workers noted that previous research on the impact of aroma, taste, and texture interactions on flavour perception has highlighted that although the physicochemical and cognitive mechanisms underlying taste-aroma interactions are mainly understood, “those determining the impact of texture on flavour perception still need to be unravelled.”
Earlier studies have suggested that aroma perception is influenced “not only by the amount of aroma compounds released, but also the rate of release and the shape of the release curve during mastication,” said the authors.
They explained that most studies to date have shown that an increase in viscosity or firmness leads to reductions in aroma perception. However reasons for this reduction may differ; “being due either to a modification of aroma release or to a perceptive interaction,” they said.
Laboure and colleagues noted that three relationships have been found between aroma perception and aroma release, “(i) aroma perception decreases but aroma release remains stable, (ii) aroma perception follows aroma release curves, and (iii) aroma perception and aroma release display opposite behaviours.”
“If a modification of aroma perception is related to aroma release, we can hypothesis a physicochemical mechanism,” they added.
In other cases, cognitive interactions may also be involved, meaning that two different mechanisms can be proposed: firstly, taste-aroma interactions may be responsible for modifying aroma perception, or secondly a modification of aroma perception could result from the direct impact of the change in the texture or structure.
The reviewers explained that product composition (interactions between macromolecules and aroma compounds), the texture (liquid or semi-solid) and structure of the matrix (type of network) all have important effects on the way aroma compounds are released.
However they added that consumer physiology, and particularly chewing behaviour, velum mobility, saliva composition and the nature of the oral mucosa also have an influence in how consumer perception of aroma.
Laboure and co-workers said their review emphasises that the relationship existing between in vivo aroma release and perception in products “is strongly dependent on the type of texture relative to two mechanisms; physicochemical mechanisms based on the modification of aroma release and a cognitive mechanism based on aroma–taste–texture interactions.”
They added that whilst the two mechanisms exist simultaneously, one may have more or less impact on aroma perception depending on the texture of the food.
Source: Flavour and Fragrance Journal
Published online ahead of print, doi: 10.1002/ffj.2036
“Aroma perception in dairy products: the roles of texture, aroma release and consumer physiology”
Authors: I. Gierczynski, E. Guichard, H. Laboure