A method for the non-intrusive determination of an indication of wholesomeness of an unopened item of packaged aliment comprising the steps of: illuminating an unopened item of packaged aliment with electromagnetic energy at a plurality of different infrared wavelengths through a suitably transparent region of the packaging so as to interact with the packaged aliment; obtaining spectral information regarding the interaction of the plurality of different infrared wavelengths with the unopened item of packaged aliment as subsequent spectral information; characterised in that the method further comprises: interrogating a machine readable tag attached to the packaging, which machine readable tag is associated with original spectral information regarding a previous interaction of the plurality of infrared wavelengths with the same unopened item of packaged aliment, to access the original spectral information; comparing some or all of the subsequent spectral information with some or all of the original spectral information to obtain a measure of spectral deviation; and determining the indication of wholesomeness based on an application of an empirical relationship to the spectral deviation, which empirical relationship links spectral deviation to a degree of wholesomeness of the unopened item of packaged aliment. illuminating an unopened item of packaged aliment with electromagnetic energy at a plurality of different infrared wavelengths through a suitably transparent region of the packaging so as to interact with the packaged aliment; obtaining spectral information regarding the interaction of the plurality of different infrared wavelengths with the unopened item of packaged aliment as subsequent spectral information; characterised in that the method further comprises: interrogating a machine readable tag attached to the packaging, which machine readable tag is associated with original spectral information regarding a previous interaction of the plurality of infrared wavelengths with the same unopened item of packaged aliment, to access the original spectral information; comparing some or all of the subsequent spectral information with some or all of the original spectral information to obtain a measure of spectral deviation; and determining the indication of wholesomeness based on an application of an empirical relationship to the spectral deviation, which empirical relationship links spectral deviation to a degree of wholesomeness of the unopened item of packaged aliment. interrogating a machine readable tag attached to the packaging, which machine readable tag is associated with original spectral information regarding a previous interaction of the plurality of infrared wavelengths with the same unopened item of packaged aliment, to access the original spectral information; comparing some or all of the subsequent spectral information with some or all of the original spectral information to obtain a measure of spectral deviation; and determining the indication of wholesomeness based on an application of an empirical relationship to the spectral deviation, which empirical relationship links spectral deviation to a degree of wholesomeness of the unopened item of packaged aliment.