Microbiology of Meat Curing

In contrast with earlier curing methods, the commercially produced modern American ham is subjected to a relatively light cure of short duration. The hams are pumped vascularly to approximately 10 per cent of their weight with a curing solution containing sucrose or glucose, sodium nitrate, sodium nitrite, and sodium chloride. The concentration of these constituents may vary within limits from one establishment to another, but in most instances the sodium chloride concentration ranges from 60 to 70 per cent of saturation. After pumping, the hams are generally submerged in a curing brine of similar composition and held at 3 to 4 C for a time ranging from a few days to 4 weeks. The hams are then removed, washed, trimmed, placed in stockinettes, and smoked and thermally processed to an internal temperature of 60 C or higher. Because of the relatively rapid methods of commercial curing of the modern ham, a study was initiated to determine what role microorganisms might play in the development of the characteristic ham flavor. In the course of this study, a unique, motile species of Lactobacillus was recognized as comprising a major proportion of the bacterial flora in ham curing brines toward the end of the curing period. The characteristics and significance of the motile Lactobacillus species are presented in this paper.