186 ◾ Fundamental Food Microbiology
Fermented Meat Products
Types
Fermented meat products are produced by first mixing meat, fat, salt, sugar, curing agents, and
spices; filling the mixture in a casing; and fermenting it either naturally or by adding (during mixing) selected starter-culture bacteria. 3 The acids produced by the starters during fermentation and
the curing agents used help control the growth of pathogenic and spoilage bacteria that might be
present in the meat. Depending on the type, the fermented products may be dried to reduce A W
or smoked or heated to ensure the safety and shelf life of the products.
Meat fermentation probably originated in the Mediterranean countries and later spread to
European countries and North America. In the United States, semidry sausages are the most
popular although some dry sausages are also produced. Following fermentation, semidry sausages
are heated (also sometimes smoked) before consumption. For dry sausages, following cooking,
the products are dried to reduce the A W . Even now, fairly large amounts of fermented sausages in
the United States are produced by natural fermentation, especially those produced by small processors. However, more processors now use selected starter cultures and controlled fermentation.
Commercial starter cultures are available as both frozen and freeze-dried concentrates for direct
inoculation in the meat mixture.
Semidry and dry sausages include many types, such as pepperoni, Genoa salami, hard salami,
summer sausage, beef sticks, beef logs, thuringer, cervelat, and Italian salami. Most are made with
beef and pork, but in recent years, some have been made with meat from chicken and turkey. The
microbiology of semidry sausages is described here.
Microbiology of Semidry Sausages
Characteristics
Semidry sausages include summer sausage, thuringer, and semidry salami. The average composition is approximately 30% fat, 20% protein, 3% minerals (salts), and 47% water. They have a
tangy taste with a desirable flavor imparted by the combined effect of lactate, acetate, and diacetyl
and some breakdown components from proteolysis and lipolysis. The use of spices also contributes to the flavor. Those containing nitrite have a pinkish color in contrast to the grayish color in
products without it.
Processing
1. Meat, salts, glucose, cure, spices, and starter mixed uniformly.
2. Stuffed in casings, fermented at 85°F–110°F (29.4°C–43.3°C) with 80%–90% relative
humidity.
3. Incubated until the pH drops to ca. 5.2–4.6, cooked to 140°F (60°C) internal temperature,
and cooled to 50°F.
4. Stored at 40°F–50°F (4.4°C–10°C) for 3–4 days, vacuum-packaged, and consumed directly.
5. Cures contain nitrite to give a final concentration of ca. 100 ppm. Fermentation can be
carried out in a smokehouse. Fermentation time is usually 8–12 h, during which the pH is
dropped to the desired level.
Fermented Meat Products
Types
Fermented meat products are produced by first mixing meat, fat, salt, sugar, curing agents, and
spices; filling the mixture in a casing; and fermenting it either naturally or by adding (during mixing) selected starter-culture bacteria. 3 The acids produced by the starters during fermentation and
the curing agents used help control the growth of pathogenic and spoilage bacteria that might be
present in the meat. Depending on the type, the fermented products may be dried to reduce A W
or smoked or heated to ensure the safety and shelf life of the products.
Meat fermentation probably originated in the Mediterranean countries and later spread to
European countries and North America. In the United States, semidry sausages are the most
popular although some dry sausages are also produced. Following fermentation, semidry sausages
are heated (also sometimes smoked) before consumption. For dry sausages, following cooking,
the products are dried to reduce the A W . Even now, fairly large amounts of fermented sausages in
the United States are produced by natural fermentation, especially those produced by small processors. However, more processors now use selected starter cultures and controlled fermentation.
Commercial starter cultures are available as both frozen and freeze-dried concentrates for direct
inoculation in the meat mixture.
Semidry and dry sausages include many types, such as pepperoni, Genoa salami, hard salami,
summer sausage, beef sticks, beef logs, thuringer, cervelat, and Italian salami. Most are made with
beef and pork, but in recent years, some have been made with meat from chicken and turkey. The
microbiology of semidry sausages is described here.
Microbiology of Semidry Sausages
Characteristics
Semidry sausages include summer sausage, thuringer, and semidry salami. The average composition is approximately 30% fat, 20% protein, 3% minerals (salts), and 47% water. They have a
tangy taste with a desirable flavor imparted by the combined effect of lactate, acetate, and diacetyl
and some breakdown components from proteolysis and lipolysis. The use of spices also contributes to the flavor. Those containing nitrite have a pinkish color in contrast to the grayish color in
products without it.
Processing
1. Meat, salts, glucose, cure, spices, and starter mixed uniformly.
2. Stuffed in casings, fermented at 85°F–110°F (29.4°C–43.3°C) with 80%–90% relative
humidity.
3. Incubated until the pH drops to ca. 5.2–4.6, cooked to 140°F (60°C) internal temperature,
and cooled to 50°F.
4. Stored at 40°F–50°F (4.4°C–10°C) for 3–4 days, vacuum-packaged, and consumed directly.
5. Cures contain nitrite to give a final concentration of ca. 100 ppm. Fermentation can be
carried out in a smokehouse. Fermentation time is usually 8–12 h, during which the pH is
dropped to the desired level.