Dairy Foods Symposium: Microbiology and flavor of cheese: Impact of Lower Salt-In-Moisture Content of Low Fat and Reduced Sodium Cheeses

To limit the impact of food on health issues as obesity, hypertension, or coronary diseases, the reduction of salt or fat content in food products without modifications of organoleptic properties remains a real industrial challenge. A better understanding of the mechanisms involved in release and perception could lead to a better formulation of diet dairy products. In this context, model dairy products with different contents of ultrafiltration retentate milk powder, milk fat and rennet were studied to better understand and quantify the role of texture and structure on physicochemical and sensory properties. The characterization of dairy products was performed by sensory methods (profile, time-intensity and temporal dominance of sensations) and by rheological (small amplitude oscillation tests, compression and texture profile analysis), structural (confocal microscopy) and physicochemical methods (determination of aroma and salt partition properties and diffusion coefficients). Salt and aroma releases in mouth (in vivo conditions) were also followed respectively by in-nose measurement (proton transfer reaction-mass spectrometry) or by measuring the evolution of saliva conductivity during consumption. A preponderant effect of fat on aroma and salty perceptions was observed, in agreement with aroma compounds and salt behaviour during in vitro and in vivo measurement. However, relating sensory perception and food product properties is a complex issue, because of the variety of phenomena occurring in the mouth during consumption (dilution with saliva, break-down during mastication etc.). To identify main mechanisms explaining release in mouth, mechanistic models, based on the description of mass transfer of salt and aroma compounds in the mouth and taking both physiological and physicochemical parameters into account, have been developed. From the predicted release kinetics of stimuli (in agreement with experimental data), the respective roles of physiological parameters and of product properties can be established.