Résumé
The health authorities recommend a reduction in salt (NaCl) and fat contents of foodstuff. But reducing such components without affecting acceptability is a major challenge, particularly because of the interactions with other ingredients, such as aroma compounds. One way could be to increase the mobility of both sodium ions and aroma compounds in food matrix and their release during consumption. This study consists in a multimodal approach to understand the effect of changes in composition of model cheeses on the mobility and release of flavour molecules (NaCl, aroma compounds). Six flavoured model cheeses have been formulated (three fat/protein contents, two NaCl contents). The rheological properties were analyzed using uniaxial compression tests. Microstructure and homogeneity were characterized by confocal laser scanning microscopy. At molecular level, sodium mobility in model cheeses was analysed by 23Na Nuclear Magnetic Resonance (NMR) spectroscopy. At macroscopic level, the kinetics of sodium release were followed in an aqueous phase and aroma release was investigated in the expired air during cheese consumption by Atmospheric Pressure Chemical Ionization-Mass Spectrometry (APCI-MS). In cheeses with a lower fat content and without NaCl added, sodium ions were less mobile, rates of sodium release were lower and times to reach maximum intensity of aroma release were longer. These effects can be explained by differences in fat/protein repartition observed in microscopy, later swallowing time of these products and a higher chewing activity. These data were put in relation with the perception of salt and aroma in the model cheeses. Understanding the effect of cheese formulation on both flavour release and flavour perception could be useful for formulation of low-salt and low-fat dairy products.