Staphylococcus

Apathogenic strains of Staphylococcus are used as starter cultures, and, thus, the environmental conditions in dry and semidry sausages also allow S. aureus to compete successfully and grow. This organism is resistant to nitrite and salt and is capable of growing under anaerobic conditions. It has a minimum water activity for growth of 0.86, and the high fermentation temperatures used in the U.S. manufacturing process favor its rapid multiplication. At fermentation temperatures of 24 to 26°C, it has been demonstrated that the risk of food poisoning, resulting from the ingestion of enterotoxin produced by S. aureus, appears to be minor, provided the initial staphylococci count is low and provided an acidifying agent is used to ensure proper fermentation (44). Recent reports discuss pathogenicity of coagulase negative staphylococci, to which group the meat starter cultures belong (45). Hemolysins are demonstrated in strains of S. carnosus and S. xylosus, for example. In addition, enterotoxin production has been demonstrated in S. xylosus. Currently, there is no information available on the biological effect of hemolysins and enterotoxins. Neither is information available on parameters and factors affecting or controlling enterotoxin production (45).

Listeria monocytogenes

Studies have shown that L. monocytogenes may survive the combination of low pH, low water activity, and nitrite, which are the built-in hurdles in dry-cured sausages (46). Consequently, listeriosis should be regarded a potential health hazard in fermented meats, although no outbreaks so far have been associated with meat (47). L. monocytogenes has been shown to survive well in European as well as American-type sausages (41,48), the decrease in initial numbers being only one log unit. The survival of L. monocytogenes in stored, dry-cured sausages is better at chill than at ambient temperature. In situ produced pediocin, a bacteriocin effective against L. monocytogenes is, however, able to control the development of this pathogen in fermented sausages (48). Recently, a bacteriocin-producing starter culture, capable of controlling L. monocytogenes, has been launched for fermented sausages (49).

Yersinia enterocolitica

Y. enterocolitica is associated with pork and, as such should be regarded a potential health hazard in dry-cured meat products. No outbreaks or recalls have been associated with the organism. A reason for this could be that the nitrite level typically employed inhibits Y. enterocolitica, particularly in conjunction with a rapid decrease in pH. For example, Y. enterocolitica was eliminated in dry-cured sausages with added 80 ppm nitrite and fermented with a fast-acidifying starter culture (50).

Fantastic Organic Food Facts

Fantastic Organic Food Facts

Get All The Support And Guidance You Need To Be A Success At Utilizing Organic Foods. This Book Is One Of The Most Valuable Resources In The World When It Comes To Getting The Right Information About Eating Healthy With Organic Food.

Get My Free Ebook


Post a comment