j. Odor and Slime. The main conditions of microbial spoilage in poultry are off-
odor (which appears at a bacterial load between 106 to 108 per cm2) and slime formation
(which occurs soon after off-odor is noted). Slime is the descriptive term which
describes the massive accumulation of microbial cells on the product surface as the
result of extensive growth. Species of Pseudomonas are the principal spoilage
organisms of poultry. Some of the chemical compounds found on spoiled chicken
included H2S (hydrogen sulfide), acetone, methanol, and many other odoriferous
compounds.
k. Gas Formation. The development of gas in cured meats is occasionally
encountered, especially in the manufacture of fermented sausages. Lactic acid bacteria
(lactobacilli and leuconostocs) and yeasts produce copious quantities of carbon dioxide
from the fermentation of the added sugar. This gas produces large numbers of pinholes
in sausage and a constant swelling of the product. Burst casings are often
encountered. Gassiness in hams and frankfurters is also observed. Among
frankfurters, the effects become dramatic when vacuum packages are used. The
packages retain the gas as it diffuses from the product and may become inflated.
l. Summary of Microbial Conditions. The various microbial conditions seen
in meat and meat products are summarized in figure 2-1.
PRODUCT
CONDITION(S)
Off-odor, Sliminess (stickiness), Discoloration, Moldiness,
Fresh red meats
Whiskers, White spot, Black spot, Bone taint, Gassiness,
Souring
Vacuum packaged
Acidity, Sweetness, Rancidity
(fresh)
Cheesy texture, Souring, Rancidity, Discoloration, Slime
Bacon
formation
Vacuum packaged
Cabbage odor Taint
(cured)
Surface slime, Gassiness or puffiness, Green discoloration
Ham
Bone and meat sours
Sausages
Slime on surface, Gas production, Greenish discoloration
Fermented sausage
Slime Spots (discoloration)
Canned meats
Gas, Putrefaction, Souring, Discoloration
Poultry
Off-odor Slime
Vinegar-pickled meats
Cloudy or ropy brine
Figure 2-1. Microbial conditions of meat and meat products.
MD0723
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