Discrimination of beef dark cutters using visible and near infrared reflectance spectroscopy.

Prieto, N., López-Campos, Ó., Zijlstra, R.T., Uttaro, B., and Aalhus, J.L. (2014). "Discrimination of beef dark cutters using visible and near infrared reflectance spectroscopy.", Canadian Journal of Animal Science, 94(3), pp. 445-454. doi : 10.4141/CJAS-2014-024  Access to full text

Abstract

To evaluate the use of residual feed intake (RFI) models measured in mid-to-late gestating beef cows, a dataset was used combining data from five experiments containing nine treatment and/or replicate groups for a total of 321 animal records. Investigations of RFI models included the effects of age, ultrasound measures of body composition, pregnancy corrected gain, and dietary treatment group. A subset of animals had serum analyzed for circulating metabolites (glucose, non-esterified fatty acids, urea, beta-hydroxybutyrate; {i}n{/i}=227) and/or linear body measures (hip This study examined the potential of visible and near infrared reflectance spectroscopy (Vis-NIRS) to segregate dark cutters from normal beef. One hundred and twenty beef carcass sides were selected from a slaughter plant by experienced graders according to their carcass grade: 60 A grade carcasses (normal) and 60 B4 grade carcasses (dark cutters). At approximately 48 h post mortem, a 2.5-cm-thick steak (at ∼7/8th thoracic vertebrae) was removed, vacuum packaged and frozen at −25°C until spectra collection. Four Vis-NIRS analyses were performed with different instruments and sample presentation. Partial least squares discriminant analysis based on Vis-NIR spectra correctly classified 95% of the intact non-oxygenated beef samples from both A and B4 grade carcasses using a portable LabSpec®4 spectrometer, and 88 and 93% of the intact beef samples from A and B4 grade carcasses, respectively after 20 min of exposure to atmospheric oxygen. When a bench top NIRSystems 6500 monochromator was used, 90% of the bloomed intact beef samples were correctly assigned to both A and B4 grading categories, and 90 and 91%, respectively, of the bloomed homogenized samples. Further work remains to be carried out to develop robust Vis-NIRS models to be implemented on-line in the abattoir, where portable equipment applied directly on the carcass could objectively assist in dark-cutting carcass segregation.

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