Salt is released gradually during the in-mouth process when eating solid foods, that results from both chewing and salivation, which enables food breakdown and taste component release. This paper deals with the development of two sensors for the in-mouth monitoring of temperature and conductivity during mastication for the in-line analysis of electrolytes extracted by the saliva. This strategy saves a considerable amount of time, as it does not require at-line sampling and analysis using time-consuming techniques, such as high performance liquid chromatography. Sensors are developed specifically to be of a certain size, and be made up of materials compatible with in-mouth applications that would ensure a high degree of safety for panelists. These techniques for the in-line monitoring of salt release during the chewing of different types of foods displayed a rapid response, no lag time, and consistent results as a function of the differences between food samples and individuals.