An installation for helping to determine the quality of pieces of meat originating from previously slaughtered animals, characterized by the fact that it includes: - at least one information medium, this information medium carrying, for each piece of meat (V; V 1; V 2; V 3), an information called "post-mortem time" information, i.e. an information characteristic of the time elapsed since the slaughter of the corresponding animal; - at least one tool for reading and recording this "post-mortem time" information; - at least one reading probe, linked to an infrared spectrometer, the latter being arranged to measure the infrared absorption spectrum of said pieces of meat (V; V 1; V 2; V 3); - at least one computer equipment (4, 5) which records each measured spectrum, which equipment is linked or connected to a database containing a predetermined number of "reference spectra", i.e. infrared absorption spectra of associated pieces of meat at different post-mortem times, this database containing also among the reference spectra, a certain number of "aberrant spectra", namely spectra which do not respect predefined parameters, this computer equipment (4, 5) being configured to: firstly, and for each tested piece of meat (V; V 1; V 2; V 3), associate the "post-mortem time" information read by said reading tool with the associated measured infrared spectrum, secondly, compare this measured spectrum with the spectrum of the database that presents the same or substantially the same post-mortem time and, thirdly and only in the event that the measured spectrum is not considered itself as being an "aberrant spectrum", associate with the piece of meat (V; V 1; V 2; V 3) a predetermined quality criterion according to the comparison performed secondly, - means for displaying the information obtained, thirdly, by said computer equipment (4, 5), even if the spectrum has been considered as aberrant. - at least one information medium, this information medium carrying, for each piece of meat (V; V 1; V 2; V 3), an information called "post-mortem time" information, i.e. an information characteristic of the time elapsed since the slaughter of the corresponding animal; - at least one tool for reading and recording this "post-mortem time" information; - at least one reading probe, linked to an infrared spectrometer, the latter being arranged to measure the infrared absorption spectrum of said pieces of meat (V; V 1; V 2; V 3); - at least one computer equipment (4, 5) which records each measured spectrum, which equipment is linked or connected to a database containing a predetermined number of "reference spectra", i.e. infrared absorption spectra of associated pieces of meat at different post-mortem times, this database containing also among the reference spectra, a certain number of "aberrant spectra", namely spectra which do not respect predefined parameters, this computer equipment (4, 5) being configured to: firstly, and for each tested piece of meat (V; V 1; V 2; V 3), associate the "post-mortem time" information read by said reading tool with the associated measured infrared spectrum, secondly, compare this measured spectrum with the spectrum of the database that presents the same or substantially the same post-mortem time and, thirdly and only in the event that the measured spectrum is not considered itself as being an "aberrant spectrum", associate with the piece of meat (V; V 1; V 2; V 3) a predetermined quality criterion according to the comparison performed secondly, firstly, and for each tested piece of meat (V; V 1; V 2; V 3), associate the "post-mortem time" information read by said reading tool with the associated measured infrared spectrum, secondly, compare this measured spectrum with the spectrum of the database that presents the same or substantially the same post-mortem time and, thirdly and only in the event that the measured spectrum is not considered itself as being an "aberrant spectrum", associate with the piece of meat (V; V 1; V 2; V 3) a predetermined quality criterion according to the comparison performed secondly, - means for displaying the information obtained, thirdly, by said computer equipment (4, 5), even if the spectrum has been considered as aberrant.