Development of an in-vitro mouth model to quantify salt release from gels

In the present study, an in-vitro mouth model to quantify salt release from food structures has been developed. In this instance biopolymer gels were used as model food systems. The model aimed to reproduce key phenomena occurring during oral processing, such as diffusion through the sample and compression. Salt release profiles from different gels (gelatin, gellan and alginate), under quiescent conditions and compression, were determined at temperatures of 25 and 37 °C. In-vitro results indicated that salt release is affected both by the type of gelling agent and by temperature. When melting took place, release occurred within seconds. However, when diffusion through the biopolymer matrix was the controlling parameter, the time scale was in the order of hours. It has been shown that compression of the gel only affects release when fractures occur. This is believed to be a consequence of increased surface area. Finally, a mathematical model has been compiled to predict release profiles when diffusion is the controlling mechanism.