Food Protection Connection: Hamming It Up for the Holidays?

(reprinted from Dietary Manager, October 2007)

Each Food Protection Connection column is approved for 1 CPE hour (level 1) for RDs and DTRs.

With holidays coming up soon, many dietary managers are already planning some special celebrations featuring a holiday classic—ham. Like any potentially hazardous food, ham can pose risks, and its unique characteristics sometimes cause confusion. So here’s your chance to “bone up” on making your ham entreés safe and wholesome for your clients.

Types of Ham

What makes a ham a ham, rather than just a cut of pork, is the curing process, which gives the meat its deep pink color. Yet this color does not necessarily mean the ham is already cooked. A ham may be ready-to-eat or not. The clue is in the labeling; a ham will be marked “fully cooked” or it will say “cook thoroughly”.

What exactly is curing? This is processing with salts and sometimes sugar and other chemicals to help preserve the meat and bring out flavor. There are many methods of curing meat. Some involve cooking and some do not, which is why not all cured meat is necessarily safe to eat as purchased. A popular curing method involves injecting the pork with a brine solution that contains salt, sugar, sodium nitrite (which gives the pink coloring), other salts, and flavorings, including smoke flavoring. This is called a “wet cure”.

Country-style ham is cured without water, by rubbing the salt mixture into the meat surface and then aging the meat. This makes for a more concentrated and saltier ham that tends to resist bacterial growth because there is so little moisture present. Whole, dry-cured ham is typically cured and stored at room temperature. Nevertheless, the USDA recommends cooking country-style hams to ensure food safety. The Italian specialty, prosciutto, is also a dry-cured ham product that may be coated with pepper. It is often served cold.

Ham Hazards

To keep ham safe and implement your HACCP plan for ham this holiday season, take a quick look at some of the foodborne hazards:

Trichinella: Beyond curing, some hams are treated specifically to kill any possible larvae of trichinella parasites (worms). Freezing or cooking generally accomplishes this. Although uncommon in pork products today, trichinella spiralis parasites can infect humans, causing foodborne illness characterized by nausea, digestive problems, and muscle aches. (The worms settle in muscles.) The illness is treatable.

An outbreak in Iowa in 1990 affected about 90 people who ate uncooked pork sausage. Most cases now relate to eating wild game rather than domestic meat, or to cultural habits that involve eating undercooked meat. Commercial hogs used to be fed a diet that included raw meat, and were thus exposed to the parasite. However, this is no longer true. US government officials say that presence of trichinella in commercial pork in the US is zero or near-zero—but still considered a hazard in isolated instances.

Clostridium: A hazard more frequently associated with ham is Clostridium perfringens bacteria, which the CDC estimates causes about 10,000 illnesses in the US each year. This is an anaerobic bug (growing without oxygen). Spores of the bacteria are a hazard on many foods, and with improper temperature control they can grow on food, be eaten, and then release toxins inside the human body. Temperature control throughout the flow of food is the best prevention. According to the FDA, “Small numbers of the organisms are often present after cooking and multiply to food poisoning levels during cool down and storage of prepared foods.” Most common occurrences are in quantity food production, as in school cafeterias, hospitals, or nursing homes. A relative, Clostridium botulinum, has also been associated with ham.

Staphylococcus aureus: These bacteria produce both an infection and a toxin. Although routine processing of “wet-cured” ham products would eliminate this hazard, the USDA says it is easy to re-introduce in food preparation. Meanwhile, dry-curing may not eliminate all of the pathogen to begin with. However, bacteria on the surface of the ham do not have favorable growing conditions. After ham is sliced, the story changes. Moisture inside the ham can get these germs started. Once a dry cured ham has been sliced, it should be refrigerated.

Mold: Mold on the exterior of a drycured ham is common. Generally, the advice is to scrub it off with a vegetable brush while washing in hot water, according to the USDA.

A focus on food products and associated hazards forms the basis for your ham HACCP plans this holiday season. An awareness of the pathogens that can follow ham through your operation and careful attention to procedures can help ensure food-safe holidays for your clients.

HAM PREPARATION TIPS

The most important step to take in developing purchasing specifications and reading package labels is to distinguish a “thoroughly cooked” ham from one that requires cooking to destroy pathogens. Vacuum-packed ham has been heat-treated to kill pathogens. Recipe procedures should match the product you purchase. Whether you are just heating ham or thoroughly cooking it, a few food-safe tips can be helpful:

• Ensure proper refrigeration for perishable ham products (at or below 41°F).
• Use fresh, cured ham within 5-7 days or before the “use-by” date on the package.
• Use opened canned ham and spiral-cut hams within 3-5 days.
• Heat ham at an oven temperature of at least 325°F.
• Allow adequate time for cooking the style of ham, e.g., 10 minutes per pound for a spiral-cut ham; up to 20 minutes per pound for a whole, bone-in, smoked ham; or up to 40 minutes per pound for an uncooked, fresh ham.
• Cook to an endpoint temperature of at least 140°F for ready-to-eat hams or 155°F for hams that must be cooked (follow the temperature standards in your local health code and/or corporate procedures).
• If ham has been re-packaged outside a USDA-inspected packing plant, heat it to an endpoint temperature of at least 165°F.
• Take the endpoint temperature by inserting the thermometer probe into the deepest part of the meat, away from bone.
• Ensure proper holding of ham products during service—at or above 135°F for hot entreés, or at/below 41°F for cold.
• Promptly cover, date, and chill any leftovers. If you will later be serving them hot, reheat to a temperature of at least 165°F.

By Sue Grossbauer