Free amino acids and dipeptides in dry-cured ham

Six types of dry-cured hams were chemically profiled for proximate composit ion and low molecular weight nonprotein nitrogen (NPN) fr actions including free amino acids (FAA) and two dipeptides (carnosine and anserine). Result s indicate that FAA were present in the six classes at different (mg/100g p rotein) concentrations, with Iberian and Serrano containing greater (P<0.05 ) amounts of most FAA. However, when analyzed as percentage (mg/100g total FAAs) values, FAA contents of Iberian and Serrano hams exhibited lower (P<0 .05) tyrosine and greater (P<0.05) aspartic acid and threonine values. With in each class, large variation coefficients (>10%) for nonprotein nitrogen paralleled inconsistent values of salt content, to which NPN and FAAs were negatively correlated (P<0.01). NPN was also negatively affected by moistur e in the dried muscle, indicating limited saltiness and greater muscle shri nkage as two major determinants in developing of nonprotein fractions, henc e of free amino acids.