Methylamino acids as indices in meat products

Abstract

SummaryA method is suggested for determining the 3‐methylhistidine and N′‐methyllysine content in meat and meat products using an ion exchange chromatography technique. 3‐methylhistidine tires showed less variation within a sample than titres of N′‐methyllysine. Concentrations of both 3‐methylhistidine and N′‐methyllysine in beef, lamb, pork and whale hydrolysates are given. In beef and lamb, the 3‐methylhistidine concentrations have a mean value 6–0 (±0.7) mg/gN. the concentrations in pork varied between 5 and 56 mg/g N, an increase in concentration being related to an increase in age, whilst those of whalemeat were consistently high (° 300 mg/gN), A dipeptide of 3‐methylhistidine and β‐alanine, as found in whalemeat extracts, appears to be present in pork and can readily be removed from both pork and whale by a prior washing procedure. the levels of the residual, protein‐bound 3‐methylhistidine are then similar to those found in beef and lamb. Interspecies variation in N′‐methyllysine is less marked. 3‐methylhistidine and N′‐methyllysine were absent from the non‐meat proteins analysed.The similar interspecies value for the 3‐methylhistidine bound to actin and myosin is tentatively suggested as an index of meat content in meat products.