Improvement of the sensory properties of dry-fermented sausages by the addition of free amino acids

The addition of free amino acids in the manufacture of dry-fermented sausages, as a method to enhance their flavour, was evaluated. For this purpose, three batches of dry-fermented sausages were manufactured: a control batch (C), and the same formula treated with 0.159% (g/100 g sausage) of a mixture of valine, isoleucine and leucine (58/35/66) (w/w) (batch L1) or treated with 1.01% of a "pool" of free amino acids (batch L2) (gly/asn/his/arg/ihr/ala/pro/tyr/val/met/ile/leu/phe/trp/lys/asp/glu/ser /gln/cys) (19/19/105/41/55/ 69/90/10/58/27/35/66/35/62/110/56/106/18/19/10) (w/w). The pH values, dry matters and water activities of experimental sausages did not show significant differences (p < 0.05) among different batches. However, an increase in the microbial counts (lactic acid bacteria and micrococci) and in the level of free amino acids and ammonia was observed in batches L1 and L2. A higher amount of volatile compounds was also detected in both experimental batches (L1 and L2), particularly those compounds derived from amino acid breakdown, such as branched aldehydes and their corresponding alcohols. In the sensory analysis, bach L1 showed a better overall quality than the control and batch L2. (C) 2004 Elsevier Ltd. All rights reserved.