Salt release and perception in model cheeses are influenced by salt/fat contents, microstructure and salt mobility

Introduction and objectivesThe health authorities recommend a reduction in salt (NaCl) and fat contents of foodstuff. Reducing such components without affecting acceptability is a major challenge, particularly because of the interactions with other ingredients such as aroma compounds. This study consisted in a multimodal approach to understand the effect of changes in composition of model cheeses on the mobility and release of sodium chloride, masticatory behaviour and saltiness perception.MethodologySix model cheeses have been formulated (three fat/protein contents, two NaCl contents). The rheological properties were analysed using uniaxial compression tests. Microstructure and homogeneity were characterized by confocal laser scanning microscopy. At molecular level, sodium mobility in model cheeses was studied by 23Na Nuclear Magnetic Resonance (NMR) spectroscopy [1] through measurement of the relaxation and the creation times. At macroscopic level, the kinetics of in vivo sodium release were determined by high pressure liquid chromatography (HPLC) [2]. Masticatory behaviour was recorded by electromyography during cheese consumption. Saltiness perception of the cheeses was assessed with a trained panel [3].Results and discussionAn increase in salt content increases the fat droplet size, decreases the firmness, increases the maximum release intensity for hydrophobic compounds and increases saltiness perception. For a same amount of salt, a lower fat content increases the firmness of the cheeses, decreases sodium ions mobility, rate and total amount of sodium release, saltiness perception. These effects can be explained by differences in fat/protein repartition observed by confocal laser scanning microscopy, a later swallowing time of these products and a higher chewing activity.ConclusionUnderstanding the effect of cheese formulation on both salt release and saltiness perception could be useful for formulation of low-salt and low-fat dairy products.