Ophidine (β-alanyl-L-3-methylhistidine, 'balenine') and other histidine dipeptides in pig muscles and tinned hams

The amounts of anserine (β‐alanyl‐L‐1‐methylhistidine), carnosine (β‐alanyl‐L‐histidine) and ophidine (β‐alanyl‐L‐3‐methylhistidine) were determined in various muscles and other tissues of pigs. The amount of the histidine dipeptides varied with age and muscle type. Ophidine accumulated in the longissimus dorsi at a rate of 25 nmol g−1 protein day−1 while the anserine concentration remained relatively constant. Thus, an estimate of the age of a pig can be obtained from the anserine: ophidine ratio in a sample of its skeletal muscle. Because the histidine dipeptides are unaffected by cooking, it is possible from an analysis of the dipeptides to monitor the type of lean pig meat used in preparing tinned hams. As the anserine:carnosine:ophidine ratio in pig meat is quite different from that in other species it is possible to distinguish between genuine and imitation hams.