Acceptable limits for Listeria Mono in Raw Meat
Does anyone have any legislation on acceptable limits of listeria mono in raw meat?
Does anyone have any legislation on acceptable limits of listeria mono in raw meat?
Hi rosanna,
•There is no set limit for Listeria monocytogenes in raw meat as the expectation is that the meat will be cooked prior to eating, which destroys the Listeria organism. Limits in ready to eat (RTE) is 100cfu/g (Codex).
Thank you Charles.
Listeria monocytogenes is a bacterium that causes listeriosis, a disease that can have severe consequences for particular groups of the population. It can cause miscarriages in pregnant women and be fatal in immunocompromised individuals and the elderly. In healthy people, listeriosis generally only causes a mild form of illness. L. monocytogenes can be found throughout the environment. It has been isolated from domestic and wild animals, birds, soil, vegetation, fodder, water and from floors, drains and wet areas of food processing factories.
Now,
The growth and survival of L. monocytogenes is influenced by a variety of factors.In food these include temperature, pH, water activity, salt and the presence of preservatives.
The temperature range for growth of L. monocytogenes is between -1.5 and 45°C, with the optimal temperature being 30–37°C.
Also
Temperatures above 50°C are lethal to L. monocytogenes.
Freezing can also lead to a reduction in L. monocytogenes numbers
Even if L. monocytogenes is absent in ready-to-eat meat and poultry products after processing, or found at very low prevalence and levels, additional contamination can occur after the packs are opened - especially when the meat is handled.
Although L. monocytogenes can grow while refrigerated, growth is very slow at temperatures below 4ºC. In ready-to-eat foods stored at higher temperatures, for example above 7ºC, growth occurs more rapidly, increasing the risk that L. monocytogenes will reach levels more likely to cause human illness. Both safe food handling and maintaining proper refrigeration temperatures are critical to minimizing the risk of listeriosis.
COOKED MEAT – Listeria is killed by cooking. Thoroughly cooking product to 165ºF/74ºC will kill the bacteria. Consumers at high risk for contracting listeriosis (e.g. pregnant women and the elderly) should reheat deli meats immediately before consumption.
FREEZING – Listeria is not killed by freezing. Growth is arrested altogether, but normal growth will be resumed after thawing.
How many bacteria are needed to cause an infection? As with all disease-causing micro-organisms there is no threshold below which there is a true “zero” risk for human illness.
The quantity of bacteria on food is expressed as the number of colony-forming units per gram (CFU/g). Levels of 100 CFU/g in food at point of consumption are regarded as safe, meaning that people consuming foods with low levels of L. monocytogenes have an extremely low risk of contracting listeriosis.
Estimates based on US data suggest though that less than 0.2% of the 2,500 listeriosis cases that occur annually in the US are caused by foods contaminated with 100 or less CFU per serving. By contrast, more than 80% of these cases are caused by foods contaminated with more than one million CFU per serving.
Thus foods that contain extremely high levels of L. monocytogenes represent the main risk for consumers.
How many bacteria are needed to cause an infection? As with all disease-causing micro-organisms there is no threshold below which there is a true “zero” risk for human illness.
The quantity of bacteria on food is expressed as the number of colony-forming units per gram (CFU/g). Levels of 100 CFU/g in food at point of consumption are regarded as safe, meaning that people consuming foods with low levels of L. monocytogenes have an extremely low risk of contracting listeriosis.
Estimates based on US data suggest though that less than 0.2% of the 2,500 listeriosis cases that occur annually in the US are caused by foods contaminated with 100 or less CFU per serving. By contrast, more than 80% of these cases are caused by foods contaminated with more than one million CFU per serving.
Thus foods that contain extremely high levels of L. monocytogenes represent the main risk for consumers.
^^^^ (red) I'm afraid that the USA will definitely not agree.
Out of genuine curiosity, why are you testing raw meat for this specific pathogen? Regulatory requirement?