How to know if lamb is spoiled? (3 easy ways)

In this brief guide, we are going to answer the question “How to know if lamb is spoiled”, discuss the different methods of identifying the spoiled lamb and the potential side effects of eating spoiled lamb.

How to know if lamb is spoiled?

To know if lamb meat is spoiled, you should be able to identify possible signs of spoilage. Some possible signs of spoilage in lamb meat are:


The detection of a greenish color accompanied by softening of the tissue may indicate the degradation by enzymatic actions of proteolytic enzymes (1).

The green-like or grayish color can be also due to the contamination of the bacteria Brochothrix (2). Discoloration and loss of red pigment may be a result of lipid oxidation and also the contamination by aerobic microorganisms. 

Discoloration may also be a result of chemical agents in the meat. Therefore, it is always necessary to evaluate the sum of the indications to determine if the meat is spoiled, as the traces are not isolated. 


The formation of off-odors in meat is a result of many factors involved in its spoilage. Off-odors such as putrid, rancid, sour, ammonia-like, and others may be signs of spoilage in meat (2)

Ammonia-like odors are the result from the action of Pseudomonas, a pathogenic bacteria. The odor of sweaty socks are due to the action of Brochothrix bacteria, while lactic acid bacteria produce acidic off-flavors. 

Oxidation of lipids results in the generation of oxidative products, such as aldehydes, acids and ketones, and free fatty acids, which characterize the rancid odor in meats (1,3). 

Fruity and sweet odors may be also due to the microbial metabolism, which generates fatty acids, ketones and alcohols, resulting in off-odors.


The softening of the tissue in meat results from the action of both enzymatic reactions or of microbial spoilage. The meat compounds, including proteins, carbohydrates and lipids, are degraded in the autolysis process (by proteolytic or hydrolytic enzymes) or by the metabolism of bacteria (2,3).

Other signs:

The formation of a slimy surface on the meat is a sign of spoilage, caused by microbial action, such as from Gram-positive organisms like Micrococcus spp (3).

Generation of gas, which is noticed by the bloating of the package, is also resulting from the action of microorganisms.

The altered flavor is also a sign of spoilage. Rancid soapy and sour taste are possible indications of microbial action or of oxidized fats. However, if you consider the possibility of spoilage, do not taste the meat, as it is not safe.

What are the possible risks of eating spoiled lamb meat?

The possible risks of eating spoiled lamb meat are of experiencing foodborne illnesses as a short term effect (1). As a long-term effect, possible negative effects are the increased risks of developing an inflammatory disease (4)

As mentioned earlier in the article, the spoilage of meat is related to microbial action. Some of these microorganisms are pathogenic, such as f E. coli O157:H7 and Salmonella, Yersinia enterocolitica, Staphylococcus aureus increased and Listeria monocytogenes which causes symptoms such as diarrhea, fever, vomiting, stomach cramps and others (5).

Fungi, virus and protozoa may also affect meat and cause negative health effects (2).

In the long term, persistent consumption of spoiled (oxidized) meat can lead to the increase of oxidized compounds in the body. Oxidized fatty acids and their degradation products can be toxic and affect the metabolism of cells. 

These compounds generate free-radicals and can be cytotoxic, leading to diseases such as cancer, atherosclerosis and early aging (4). In addition to the bad odor and flavor, rancidity in meat can be unhealthy and should be avoided.

How to prevent the spoilage of lamb meat?

To prevent the spoilage of lamb meat, follow the instructions (2,6):

  • Store meat right after purchase, avoid unrefrigerated transport of meat
  • Always check the best-by date indication to consume the product. If no date is given, cook or freeze within 3 days after purchase
  • Store meat in the refrigerator for 3 days or in the freezer. In the case of minced lamb meat, consume it in 2 days. For best quality, use frozen lamb roasts, steaks, and chops within 6 to 9 months; ground lamb, 3 to 4 months
  • Thaw the frozen meat in the refrigerator overnight
  • Use clean utensils and wash hands properly to handle and prepare lamb meat, avoid cross-contamination with other foods and do not use the same utensils used in preparing meat to prepare other foods
  • Cook all organ and variety meats (such as heart, kidney, liver and tongue) to 160°F and lamb steaks, chops, and roasts to a minimum internal temperature of 145°F 
  • Cooked lamb meat should be stored in the refrigerator for a maximum period of 4 days
  • Do not store partially cooked lamb meat


In this article, we discussed possible signs to identify whether or not lamb has gone bad. By checking the color, texture, odor and the presence of slime or gas you can know that the meat is spoiled and avoid its consumption. is slimy or you experience some kind of rotten smell, this indicates that the lamb has been spoiled. Eating rotten lamb can cause health problems, notably nausea, vomiting, abdominal pain, and stomach pains.


  1. Berruga, M. I., H. Vergara, and L. Gallego. Influence of packaging conditions on microbial and lipid oxidation in lamb meat. Small Ruminant Res, 2005, 57, 257-264.  
  2. Dave, D., and Abdel E. Ghaly. Meat spoilage mechanisms and preservation techniques: a critical review. Am J Agric Biol Sci, 2011, 6, 486-510.  
  3. Sun, Xiang Dong, and Richard A. Holley. Antimicrobial and antioxidative strategies to reduce pathogens and extend the shelf life of fresh red meats. Comprehen rev food sci food safe, 2012, 11, 340-354.  
  4. Vieira, Samantha A., Guodong Zhang, and Eric A. Decker. Biological implications of lipid oxidation products. J Am Oil Chem Soc, 2017, 94, 339-351.
  5. Foodborne illness and disease. United States Department of Agriculture  
  6. Lamb from farm to table. United States Department of Agriculture 

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