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

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.