There is a need to reduce the amounts of salt in food products to avoid the incidence of health problems. The aim of this study was to investigate the influence of composition and structural characteristics of food matrices on the mobility and release of salt.
Gels composed of protein (gelatin or milk protein), fat (oil-in-water (O/W) emulsion) and salt were used as the model system. The concentration of these ingredients was varied to obtain gels with different compositions and structural characteristics. The kinetics of sodium release from gels to an aqueous phase, the water/gel partition coefficient of sodium and the sodium ions mobility (measure by NMR spectroscopy) were determined.
The type and concentration of protein affected the water/gel partition coefficient of sodium. Gels with milk protein had a lower partition coefficient than gels with gelatin. Increasing the protein concentration increased the partition coefficient. In gels with a constant concentration of protein, the partition coefficient increased with increasing the fat concentration and decreased with increasing the salt concentration. No effects of protein and fat were observed on the kinetics of sodium release from gels to an aqueous phase. The release rate of sodium decreased as the concentration of salt increased. The mobility of sodium ions, which was measured by NMR spectroscopy, was also affected by the composition of the gels. Sodium ions mobility increased with increasing the protein and salt concentration. Gels with milk protein had a higher sodium ions mobility than gels with gelatin.
These findings suggest that the composition and the structural characteristics of food matrices can be modulated in order to maximize the release of salt in the mouth during oral processing. As a consequence, saltiness perception could be enhanced and the amounts of salt could be reduced without affecting the taste quality of food products.
Dr. Ana Carolina Mosca Ana-Carolina.Mosca@dijon.inra.fr
