Nitrogen factors for beef: a reassessment

Abstract

Nitrogen factors (the percentage of nitrogen on a fat-free basis) for beef were estimated using a total of 43 clean beef carcases and 30 cull cow carcases from six commercial abattoirs. The sample included carcases representative of the European Community classification ranges for fatness and conformation. The nitrogen factors for the lean meat with intermuscular fat for the whole sides of clean beef and cull cow beef were 3.65 and 3.70, respectively. For beef generally, a nitrogen factor of 3.65 is recommended for use in the analysis of beef and beef products. Nitrogen factors for different commercial joints differed significantly and the appropriate joint value should be used where the nature of the joint is known. Those for cull cow beef were generally higher than those for clean beef. All factors estimated were higher than 3.55, the value recommended for beef by the Analytical Methods Committee in 1963. Fat, moisture, ash, hydroxyproline and nitrogen contents in each joint and also in the side are reported in this paper.