Washington—The US Codex Office is sponsoring a public meeting on Jan. 27, 2022, to provide information and receive public comments on agenda items and draft US positions to be discussed at the 52nd session of the Codex Committee on Food Hygiene (CCFH).
The CCFH of the Codex Alimentarius Commision will meet virtually Feb. 28-Mar. 4, 2022, with the report adoption on Mar. 9, 2022.
Among the items on the agenda for the 52nd session of the CCFH that will be discussed during next month’s US Codex Office meeting, which
will take place via video teleconference only, is proposed draft
guidelines for the control of Shiga toxin-producing Escherichia coli
(STEC) in beef, raw milk and cheese produced from raw milk, leafy
greens, and sprouts.
The
guidelines build on general food hygiene provisions already established
in the Codex system and propose potential control measures specific for
STEC strains in raw milk and raw milk cheeses and the other listed
foods. The guidelines provide information to industry and governments on
the control of STEC.
One
annex of the guidelines concerns specific control measures for raw milk
and raw milk cheeses. The objective of the annex is to provide
science-based guidance for the control of STEC related to raw drinking
milk and raw milk cheeses; the guidance focuses on control of STEC
during raw milk production (cows, buffaloes, goats and sheep), raw milk
cheesemaking, storage, distribution and consumer use of these products.
There
are no interventions shown to be consistently effacacious in
significantly reducing or eliminating STEC in ruminant intestines, the
annex explained. In addition, no interventions specific for small
ruminants are suggested.
Control
measures should be implemented to minimize spread between animals and
their environments. The following are examples of measures that may be
useful: maintain animal health and, where possible, minimize animal
stress; keep litter and bedding as dry as possible; apply pest control
practices; if possible, limit fecal contact with newborn or young
animals; keep young cattle in the same groups throughout rearing without
introducing new animals; and apply hygienic practices for manure and
slurry management.
STEC
can also potentially persist on milking equipment and pipelines if
these are not adequately cleaned, the annex noted. All equipment that
may come in contact with milk, such as tubes and pipes used for
transferrring milk to larger containers, pumps, valves, storage
containers and tanks, etc., should be thoroughly cleaned and disinfected
before every use.
STEC
can rapidly multiply in raw milk if the milk is at the temperature of
STEC growth, so temperature control of the milk post-harvest is crucial.
Milk should be maintained cold during its storage on the farm and
throughout the collection route to prevent microbial growth.
Temperatures
of 6 degrees C or above, extended storage of raw milk, and initial
bacterial counts in raw milk during collection, storage and
transportation have been associated with increased counts of E. coli in
raw milk. Milk temperature should be monitored during storage and
checked before it is unloaded, if possible.
As
far as raw milk cheeses are concerned, the different processing steps
applied, and the raw milks used for different species, can influence the
behavior and survival of STEC strains, the annex explained. The
behavior of STEC (survival, growth or inactivation) can also be
influenced by temperature, by the intrinsic physico-chemical properties
(pH, water activity, percent lactic acid) and by other microflora
present specific to different cheeses during their manufacture.
At
the initial stages of cheesemaking, the temperature and water activity
value of milk provide favorable conditions for the growth of STEC.
During the first hours of cheesemaking (transition from milk to curd),
an increase in STEC level by 1-3 log can be observed for some
cheesemaking technologies.
This
increase in number is due to the multiplication of the cells in the
liquid milk and then in the curd where cells are entrapped.
“Cooking”
of curd, and rapid acidification (when pH decreases to under 4.3)
coupled to the increase of non-dissociated lactic acid, were associated
with a range in STEC or E. coli log reductions. The magnitude of
reduction varied by STEC serotype and type of cheeses, depending on
their intrinsic physico-chemical characteristics.
During
the ripening step, the microbial stability of cheeses is determined by
the combined application of different hurdle factors (low pH, water
activity values, salt, non-dissociated lactic acid, starter cultures,
Penicillium mold). These hurdles make the cheese become an increasingly
challenging environment for STEC during the manufacturing process and
ripening, the annex noted.
The
contamination of dairy products with STEC during processing in
manufacturing plants is rare if appropriate hygiene practices are
followed, the annex stated.
The
food business operator should analyze the risks associated with its
manufacturing process regarding the potential growth or decline of STEC.
Based on this assessment, the FBO should adapt the process and/or
implement controls to reduce any identified risks for STEC contamination
and growth.
Jenny
Scott, US delegate to the 52nd session of the CCFH, is inviting US
interested parties to submit their comments to her via email at: [email protected].