A pressure sensor device and its use for confirming achievement of a selected pressure in a high pressure process (HPP) for sanitizing food is disclosed. The device includes at least a base and a sheet, each of which is substantially impermeable to the working fluid of the HPP and is deformable at the selected pressure. Microcapsules interposed between flat overlapping portions of the base and sheet contain a color former and burst upon pressurization of the environment surrounding the device. Release of the color former is detected to confirm that the pressurization occurred. The device can be associated with one or more foodstuffs (e.g., a packaged food product or a group of such packages) and remain associated therewith to continuously indicate that the foodstuff(s) have been subjected to the selected pressure and are therefore sanitized.