Résumé
Health authorities recommend food industries to reduce salt and fat in food products. But reducing such. components in food is a main challenge, particularly because of the interactions with other ingredients,. such as aroma compounds. Indeed, a change in salt or fat content can lead to a change in texture and. structure which can affect food oral processing, aroma release1 and thus perception. The aim of this. project was to study the consequences of a change in salt (NaCl) or fat contents on the aroma release. during eating (chewing behaviour, swallowing). Therefore, six model cheeses have been formulated. (three lipid/protein ratios, with and without salt added). They were flavoured with a mixture of aroma. compounds (diacetyle, butanoic acid, heptan-2-one, ethyl butanoate, octan-3-one, nonan-2-one and ethyl. hexanoate). Differences in cheese texture parameters were measured by uniaxial compression test and. were related to differences in microstructures observed by image analysis on confocal laser scanning. micrographs. In vivo aroma release was followed during cheese consumption by Atmospheric Pressure. Chemical Ionization-Mass Spectrometry (APCI-MS) on ten subjects. Chewing behaviour was. simultaneously followed by surface electromyography (EMG) and swallowing events were recorded. during consumption. Variations in cheese composition induced variations in texture and then in oral processing. The chewing. behaviour, in particular the number of bursts, the time of mastication and the chewing work increased for. the products with the lower lipid/protein ratio. Increasing salt level induced a decrease in time before. swallowing and an increase in the number of swallowing events for harder products. In addition, the. nature of aroma compounds modified both the maximum intensity of release (Imax) and the time to reach. the maximum intensity (Tmax). Imax increased and Tmax decreased from ketones to esters and from high. to low hydrophobicity. Moreover, both the lipid/protein ratio and the salt content influenced the kinetics. of aroma release during the consumption of the model cheeses and these effects were mainly explained by. differences in eating behaviours. A shorter release (Tmax) in cheeses with salt added was explained by a. faster swallowing of these products. Tmax also decreased when the lipid/protein ratio increased because. the products required a less important chewing activity. Finally an increase in the number of swallowing. events during consumption led to an increase in global aroma release. Although this study also showed. important inter-individual differences, they do not hide differences between products. The results point. out the fact that salt and fat reduction not only changes the textural properties of model cheeses but also. modifies the oral processing and the kinetics of in vivo aroma release. These conclusions are important to. take into account for the formulation of low-salt and low-fat foodstuff.