Free amino acids and dipeptides in dry-cured ham

Six types of dry-cured hams were chemically profiled for proximate composition and low molecular weight nonprotein nitrogen (NPN) fr actions including free amino acids (FAA) and two dipeptides (carnosine and anserine). Results indicate that FAA were present in the six classes at different (mg/100g protein) 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. Within 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 moisture in the dried muscle, indicating limited saltiness and greater muscle shrinkage as two major determinants in developing of nonprotein fractions, hence of free amino acids.