Behavior of Staphylococcus aureus in sucuk with nettle (Urtica dioica L.)

The behavior of Staphylococcus aureus was studied in sucuk (Turkish dry fermented sausage) with different levels of nettle (Urtica dioica L.). Sucuk batters containing different levels (1, 3 and 5%) of nettle were prepared and contaminated with S. aureus at approximately 10(4) cfu/g. Sucuk batter not inoculated with S. aureus and not containing nettle addition was set as the control lot. Lactobacillus sakei Lb 706 was used as a starter culture. During ripening period, S. aureus, Micrococcus/Staphylococcus and lactic acid bacteria counts were determined. pH and water activity (a(w)) values were also analyzed. The S. aureus count was under detectable levels in the control lot, and the pH level dropped below 5.0 after the first 24 h of fermentation. Initial pH values increased gradually in all three lots (1, 3 and 5%). At the end of the first 24 h of fermentation, a significant increase in S. aureus counts was determined in all lots of sausage except for the control lot. The pH value of the sucuk sample containing 1% nettle was under 5.0 on the second day. However, pH values for sucuk samples containing 3 and 5% nettle did not drop below 5.0 during the ripening period, including the fermentation phase. Nettle usage had no effect on the lactic acid bacteria count; however, it had significant effects on the Micrococcus/Staphylococcus count and a(w) value.