The fluorometric determination of 3‐methylhistidine in meat and meat products

A fluorometric procedure for the determination of 3‐methylhistidine in meat and meat products has been developed. Acid hydrolysates are neutralised and treated with fluorescamine; the products are then heated in acid at 80°C for 1 h. Histidine and 3‐methylhistidine are two of the few amines giving acid‐stable fluorescent derivatives: these are separated by high‐performance liquid chromatography and determined fluorometrically. The method is simple, rapid, specific and sensitive. Levels of protein‐bound 3‐methylhistidine in different meat species are constant at about 5 mg g−1 non‐collagen nitrogen, and correspond with literature values, though high values for chicken are not observed. Recoveries of 3‐methylhistidine added to the meats are satisfactory (98–109%) and the method has been applied to a complex soup powder which has hitherto defied analysis.