Evaluation of a rapid protein analyzer as a research tool for lean beef composition: Effects of storage time and freezing

•Sprint is a potential alternative protein determination method in research.•Storage and handling protocols do not appear to affect Sprint protein values.•New calibrations are necessary for compositional range of specific products.•Properly calibrated, it may be ok for protein content determination in lean beef.•Where accuracy is critical, better options are still Dumas or Kjeldahl methods.

The Sprint Rapid Protein Analyzer (CEM Corporation) has introduced a novel method for protein content determination. Dairy and meat industries are adopting this technology, as it is easily integrated in commercial plants; however, its application as a valid tool for meat research requires further evaluation. Using the Dumas method as a reference, the Sprint Rapid Protein Analyzer was tested to evaluate the accuracy, precision and repeatability of the machine, under a variety of different beef muscle sample storage and handling conditions. The samples analysed using the Sprint Rapid Protein Analyzer showed an average within-day relative standard deviation (RSD) of 0.812% and an average inter-day RSD of 1.39%. For samples stored at 4 °C for 24, 48 or 72 h, the RSD ranged between 0.02 and 4.50%. In samples frozen at −35 and −80 °C for 2, 4, 6, 8, 10 and 12 months, the average RSD compared to fresh samples was 2.89%. Thus, the Sprint method, once properly calibrated over the compositional range encountered, may be suitable for use to determine protein content in lean beef research.