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The effect of the partial NaCl replacement by other salts (potassium, calcium, and magnesium chloride) on the formation of volatile compounds through the processing of dry-cured ham was studied using solid-phase microextraction (SPME). Three salt formulations were considered, namely, I (100% NaCl), II (50% NaCl and 50% KCl), and III (55% NaCl, 25% KCl, 15% CaCl(2), and 5% MgCl(2)). There was an intense formation of volatile compounds throughout the processing of dry-cured hams, particularly during the "hot-cellar" stage. The differences between treatments were found to be more remarkable at the end of the curing process. Hams from formulations I and II had significantly higher amounts of lipid-derived volatiles such as hexanal than hams from formulation III, whereas the latter had significantly higher amounts of Strecker aldehydes and alcohols. Plausible mechanisms by which salt replacement may affect the generation of volatile compounds include the influence of such replacement on lipid oxidation and proteolysis phenomena. The potential influence of the volatiles profile on the aroma of the products is also addressed in the present paper.

Lactobacillus casei CRL 705 was screened, among other meat isolates, for its proteinase and aminopeptidase activities toward synthetic substrates and, according to that, selected for specific assays on muscle proteins. The hydrolytic effects of whole cells, cell free extracts (CFE), and the combination of both on muscle sarcoplasmic and myofibrillar protein extracts was evaluated by SDS-PAGE and reverse phase HPLC analyses. The proteinase activity of whole cells caused the degradation of a great number of sarcoplasmic protein bands. A partial hydrolysis was also associated with CFE that when combined with whole cells showed an important additional degradation. Peptide profiles from sarcoplasmic protein extracts were greatly modified regardless of the addition of whole cells or CFE, although their combination intensified these changes. The generation of free amino acids was remarkable when whole cells and CFE were incorporated together to sarcoplasmic protein extracts.