Technological and safety characteristics of Staphylococcaceae isolated from Spanish traditional dry-cured sausages

Abstract

The aim of this study was to determine the technological properties (nitrate reductase, proteolytic and lipolytic activities; and the ability to grow at the temperature and pH values of fermenting sausage, and at high NaCl concentrations) and safety characteristics (amino acid decarboxylase and enterotoxigenic activities) of 38 strains of Staphylococcaceae (11 of Staphylococcus epidermidis, 15 of Staphylococcus equorum, 5 of Staphylococcus pasteuri and 7 of Staphylococcus saprophyticus) isolated from Androlla and Botillo, two Spanish traditional sausages, in order to evaluate their suitability as potential starter cultures in the manufacture of these sausages. Most strains were able to grow at 10 °C, in the presence of 10% and 15% NaCl and at pH values of 5.5 and 5.0, except for S. equorum strains, growth of which was reduced at these pH values. The proteolytic activity assessed by the agar plate method showed that 89.5% and 52.6% of the strains were able to hydrolyze sarcoplasmic and myofibrillar proteins, respectively. These results were not confirmed by electrophoretic assays as only 47.2% of the strains changed the SDS-PAGE profile of actin, myosin and/or sarcoplasmic protein extracts. The assessment of the lipolytic activity by titration showed that only 21.0% of the strains can hydrolyze pork fat to any extent; whereas the profiles of the freed fatty acids were different in the different strains. Most of the strains showed decarboxylase activity against histidine, lysine, ornithine and tyrosine, but the quantities of biogenic amines produced were in most cases <25 ppm and <5 ppm for putrescine and cadaverine, respectively. Only four strains (10.5%), of S. epidermidis, produced enterotoxin C.