Staphylococcus aureus survival, staphylococcal enterotoxin production and shelf stability of country-cured hams manufactured under different processing procedures

Fresh hams were inoculated with Staphylococcus aureus, cured, equalized, cold smoked or non-smoked, and aged. Initial S. aureus populations of 8.57 and 8.12 Log₁₀ CFU/cm² for salt and salt + NO₂hams decreased to below the levels of detection after the fourth month of aging. S. aureus was detected following enrichment for 75% of the inoculated and 62% of the control hams at the end of the aging period. Staphylococcal enterotoxin was detected in 40% of the inoculated and 50% of the control hams following the aging period. The NaCl content of these hams with or without nitrite were 4.45/3.37% and a_w values 0.94/0.91. Country-cured ham products obtained from retail stores in Kentucky were all negative for S. aureus enterotoxin. These results indicate that higher salt content and lower a_w values on country-cured hams play an important role in controlling the growth and toxin production of S. aureus.