Update of Food Authority Auditors Forum

In August, the Food Authority held an auditor’s forum for all TPA’s (Third Party Auditors), this is an opportunity for auditors to ask questions that have come up during the previous years’ audits.

One of the issued discussed was the use of ready to eat (RTE) sliced meat by facilities and whether a “use by” date applied to the product is an appropriate control (to use before the use by date), for the food or whether the “7 days from packaging” that people may have heard of is more appropriate.

The answer form the Food Authority is to use the “7 days from packaging” control for RTE sliced meats, this is to control any Listeria that may be present within the food and due to the type of people that the food is being served to, for example, vulnerable persons.

Listeria Monocytogenes (commonly referred to as Listeria) is bacteria that is present in the general environment and may also be present in food manufacturing premises, the properties of Listeria include: -

·      Listeria is a facultative anaerobe, which means it can grow under aerobic, (with oxygen), microaerobic and anaerobic (without oxygen), conditions and in the presence of CO₂ (carbon dioxide) – which means it can grow in vacuum packaging;

·      Listeria is Psychotrophic, which means it can grow at temperatures of 4⁰ C and lower, it can even grow at -1⁰ C;

·      Listeria can develop flagella for motility when grown at 20⁰ C to 25⁰ C;

·      Will typically grow in a pH range of 4.5 to 9.7;

·      Is salt tolerant for growth up to 10% salt, (as a comparison the ocean is approximately 3.8% salt), it can also survive in high salt environments (16% salt) for up to 12 months;

·      Can survive in environments with a low water activity such as straw and soil;

·      Listeria is a biofilm producer, this means that the bacteria is difficult to dislodge during cleaning and provides a protection against sanitisers for internal cells in the biofilm;

·      Listeria has a growth “lag phase” (how long it takes to start to grow/multiply), of 120 to 148 hours (approximately 6 days) – this is the reason for the “7 days from packaging” precaution.

When it comes to the mortality rate for Listeria, although it is not a leading cause of foodborne illness, L. monocytogenes is among the leading causes of death form foodborne illness, it is estimated: -

·      There are 255 deaths in the U.S annually;

·      The severe form of the infection has a case-fatality rate of 15% to 30%;

·      For Listerial meningitis this is 70%, for septicaemia 70% and for perinatal/neonatal infections >80%;

With an onset time or incubation period of between 3 days to 3 months, determining what has been eaten when sick with Listeria is very difficult. For food businesses serving food to vulnerable persons, there must be adequate precautions in place, such as: -

·      Only purchase RTE sliced meat from an approved supplier with a Listeria management program in place;

·      Only accept high risk food into the business that is at the correct temperature, has intact packaging and appropriate use by/packed on dates;

·      Only use RTE sliced meat within 7 days from packaging.

*Some information taken from Food Authority publications regarding the control of Listeria Monocytogenes.