Changes in nitrogen fractions and free amino acids during ripening of Spanish dried beef "cecina"

The changes in nitrogen fractions (total nonprotein nitrogen -NPN-, amino acid nitrogen, peptide nitrogen and volatile basic nitrogen) and free amino acids during the ripening of "cecina" (a Spanish dried beef product) were tracked The amount of fetal NPN, amino acid nitrogen and volatile basic nitrogen increased during processing, while peptide nitrogen decreased in the last stage. An increase was observed in all amino acids except taurine. In final product, the most abundant free amino acids were leucine-isoleucine mixture, lysine and proline-methionine mixture. Taking into account the concentrations of the most abundant amino acids detected in cecina and the taste threshold; described for L-amino acids in water, it appears that several amino acids ie. lysine, alanine, valine and glutamic acid, could contribute to the flavor of this meat product.