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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].

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