Botulism, Trichinosis, etc.

The Case for Curing

Introduction: These days, we read a lot about "uncured" products, especially sausages and bacon. Read on for some writings about what's REALLY going on here! There was a scare about carcinogens being formed by curing additives. The FDA looked into it, set standards, and determined that the only problems appeared to be caused by nitrate content in bacon which has been over-cooked. I'll reference a few publications below, adding some of Barry Bryner's writings, and hope you'll feel better about meat curing. There's not only a good reason for correctly curing meats, it's absolutely essential.

An aside, here, but not really- - commercial meat processors have found that they can dose their products with celery juice, which can run the nitrate content up to 4000 ppm. It's "organic," though, so they can get away with calling their product "uncured" while socking the hell out of the nitrate content! Canada regulates this. The USA does not. (...still in favor of rolling back federal regulations? What were you thinking? Write your congressman.)

We have a couple of bad guys to worry about: botulism and trichina. We have weapons, though- - cures, salt, heat treatment (to include cooking), and freezing. The FSIS, a division of the USDA, gives specific guidelines about this sort of thing. (See references and specific quotes below.) Used in controlled amounts, these cures and techniques work well in controlling the "bad guys." If you intend to make sausages, you need to know about them:

  • Nitrites
  • Nitrates
  • Salt
  • Heat
  • Freezing
  • Cleanliness

What follows are a few items discussing control of botulism and trichinella, pls some background on the USDA and the FSIS.

Want to read up on federal requirements? The FSIS puts out an excellend summary. Check the internet for "FSIS Processing Inspectors Calculation Handbook 7620-3" which is available in PDF format, available at:

Botulism Story, A Baffling Mystery:

by Barry Bryner

In Sweden during the 1970's, a single case of food-borne bolulism completely baffled medical authorites for more than a week. A father had been out with his 7-year old son hunting roe deer and since they lacked a freezer, they made meatballs and preserved them in jars. Experienced as they were, they followed all safety rules with sterilization of the jars etc. After a couple of months, the son opened a jar to have a taste and ate ONE meatball. He fell sick with botulism and was admitted to the emergency room at a hospital. Only because of quick diagnosis and treatment, the boy finally recovered following several weeks in a hospital, as authorities investigated every possible clue for answers. (In Sweden, the law requires an investigation regulated by their bureau for Infectious Disease Control).

The contents of all the jars were examined by specialists, though only one jar in particular seemed to be the only one infected! Investigators were completely puzzled! What had caused the infection of merely one jar? Following further investigation, it eventually turned out that when the deer was shot, the bullet had slightly grazed against the trunk of a tree before killing the game. A few spores from the tree had obviously followed the bullet into the wound to eventually end up in the preserved meat. Boiling the jars killed LIVING bacteria, but not the spores that found ideal growth conditions during the subsequent storage.

Do you know how the rod-shaped pathogenic bacterium was first isolated? It has only been a little over a hundred years ago. Yup, some crazy home-sausage makin’, cow biscuit kickin’, dude with a bad comb-over just like mine… made a “bad” ham. (Meaning no curing agent was used). That was in 1896. Several people consumed the bad ham and it was later discovered that due to the enzyme superoxide dismutase, the bacterium actually tolerated very small traces of oxygen. All fell victim of the bad ham and died! Scientists finally identified and named clostridium botulinum.

Now, get this! Botulinum spores are extremely persistent and will survive heating up to 250°F. (121°C), freezing, smoking, and drying. When the right conditions occur they become active but give no foul smell or taste, making the bacteria even more treacherous.

In non-cooked fermented sausages, the microorganism must be destroyed using a combination of salt, sodium nitrate cure, a drop beyond 5.0 pH, and a minimum drop in Aw water activity to 0.97 or less. (We'll discuss water activity later. Suffice it to say that tying up water limits bacterium activity. That's why dried foods can be shelf-stable.)

Destroying Trichinella Spiralis in Pork:

by Barry Bryner

In 2003, Dr. M. Ellin Doyle at the University of Wisconsin in Madison wrote that trichinella spiralis is so resistant to salt that it takes 8 to 9 percent to kill the larva. Levels above about 4 per cent are not palatable to humans. Many dry-cured (raw) sausages are prepared with salt levels nearing 3-1/2 per cent because the higher salt volume controls pathogenic bacteria by "binding" the water (Aw) until the lactic acid bacteria has had a chance to work by competing with the pathogenic bacteria for sugar.

A couple of years ago, a new sausage maker wrote in and asked:

Do you guys freeze your pork to kill any possible trichinae before making salami or just take a chance and not worry about it?

Absolutely we freeze pork to kill any possible trichinae. But simple freezing will not destroy the microorganism. We must "Deep" Freeze meat - BELOW ZERO! Although the FSIS has done much to eradicate the disease by enforcing modified laws, especially after the mid 1970’s, there yet remain about 40 cases of trichinosis each year in the U.S. alone. Most of these cases stem from smaller farms yet feeding their stock the entrails of previously slaughtered pork and because it has not yet been completely alleviated and we must never take a chance or take it for granted that it couldn’t yet possibly affect our sausage making.

In North America, there are five known species of Trichinella. They are Trichinella spiralis, T. nativa, T. pseudospiralis, Trichinella T-5, and Trichinella T-6. The one we deal with most often in pork is trichinella spiralis. The other four occur mostly in game animals. Species T-5 is found mostly in bears and other wildlife in the eastern United States, while species T-6 is mostly in bears and other wildlife in the Northwestern United States. Species T. nativa is found in Alaska. Both T. nativa and Trichinella T-6 are resistant to freezing. Trichinella pseudospiralis has been reported infrequently from birds, but can infect pigs also.

You would be surprised at just how many people believe that simple freezing will destroy trichinella spiralis. Actually, the majority of people believe it, and that frightens me. I often think of the folks who shoot javelinas and think simply freezing the carcass will take care of trichinella spiralis. It absolutely will not! In fact, The Division of Infectious Disease, Department of Medicine, at Massachusetts General Hospital has concluded that “Smoking, salting, or drying meat are not reliable methods of killing the organism that causes this infection”. Further, "Only freezing at subzero temperatures (Fahrenheit) for 3 to 4 weeks will kill the organism". If folks ever gazed into a microscope and saw the round nematode worm embedded far into human muscle tissue, they would surely think twice about proper sub-zero temperatures. The first time I saw the living microorganism beneath the microscope, I thought I'd lose my lunch! The thing that alarms me is that most people do not have the means of freezing meat at these cryogenic temperatures - so, they take the chance. Yet, if the pork has come from a reliable grocer rather than an "independent small farmer", you will be pretty much safe.

'Wanna get' really scared? Here's how the little buggers work: Trichinella cysts break open in the intestines and grow into adult roundworms whenever a person eats meat from an infected animal. These roundworms produce other worms that move through the stomach wall and into the bloodstream. From here, the organisms tend to invade muscle tissues, including the heart and diaphragm, lungs and brain. At this point, trichinosis becomes most painful.

But we can get rid of it right? Wrong! The medications Mebendazole or albendazole may be used to treat infections in the intestines, but once the larvae have invaded the muscles, there is no specific treatment for trichinosis and the cysts remain viable for years. Complications of the disease include encephalitis, heart arrhythmias, myocarditis, (inflammation), and complete heart failure. Pneumonia is also a common complication. So, what do we do? Purchase pork from a known, reliable, suppliers who conform to USDA and FSIS rules and imports commercially-grown pork. Or, you can cryogenically treat your own if you are a small producer of hogs and insist on feeding your piggies the entrails of other animals.

Employing FSIS rules, hog producers have come so far since the mid 1970's that trichinella spiralis isn't much of a threat any longer in commercial pork. However, about 40 people a year are still infected by pork that has been "home grown" by local hog raisers who will not comply. When the animal's feed is infected, the cycle starts all over again. One of these days, small producers will "get it" and adhere to modern feeding practices recommended by the USDA.

For your reference, here are the rules of the United States Department Of Agriculture - Meat Inspection Division for destroying trichinae:

The Meat Inspection Division of the United States Department Of Agriculture arranges the size, volume, and weight of meat products into “groups” to specify handling instructions.

Group 1 “comprises meat products not exceeding 6” (inches) in thickness, or arranged on separate racks with the layers not exceeding 6” in depth, or stored in crates or boxes not exceeding 6” in depth, or stored as solidly frozen blocks not exceeding 6” in thickness”.

Group 2 “comprises products in pieces, layers, or within containers, the thickness of which exceeds 6” but not 27” and products in containers including tierces, barrels, kegs, and cartons, having a thickness not exceeding 27”. The product undergoing such refrigeration or the containers thereof shall be spaced while in the freezer to insure a free circulation of air between the pieces of meat, layers, blocks, boxes, barrels, and tierces, in order that the temperature of the meat throughout will be promptly reduced to not higher than 5 degrees F., -10 degrees F., or -20 degrees F., as the case may be”.

Item 1: Heating & Cooking

“All parts of the pork muscle tissue shall be heated to a temperature of not less than 138° F.” Whenever cooking a product in water, the entire product must be submerged for the heat to distribute entirely throughout the meat. Always test the largest pieces since it always takes longer to reach the 138°F temperature in thicker pieces. Always test the temperature in a number of places.

Item 2: Refrigerating & Freezing

“At any stage of preparation and after preparatory chilling to a temperature of not above 40° F., or preparatory freezing, all parts of the muscle tissue of pork or product containing such tissue shall be subjected continuously to a temperature not higher than one of these specified in Table 1, the duration of such refrigeration at the specified temperature being dependent on the thickness of the meat or inside dimensions of the container.”

Table 1: Required Period Of Freezing At Temperature Indicated

Temperature Group 1 (first number of days) Group 2 (second number of days)

+05° F. 20 days / 30 days-10° F. 10 days / 20 days-20° F. 6 days / 12 days

Item 3: Curing Sausage

“Sausage may be stuffed in animal casings, hydrocellulose casings, or cloth bags. During any stage of treating the sausage for the destruction of live trichinae, these coverings shall not be coated with paraffin or like substance, nor shall any sausage be washed during any prescribed period of drying. In preparation of sausage, one of the following methods may be used:

Method No. 1:

“The meat shall be ground or chopped into pieces not exceeding ¾” in diameter. A dry-curing mixture containing not less than 3-1/3 lbs. of salt to each hundredweight of the unstuffed sausage shall be thoroughly mixed with the ground or chopped meat. After being stuffed, sausage having a diameter not exceeding 3-1/2” measured at the time of stuffing, shall be held in a drying room not less than 20 days at a temperature not lower than 45 degrees F., except that in sausage of the variety known as pepperoni; if in casing and not exceeding 1-3/8” in diameter at the time of stuffing, the period of drying may be reduced to 15 days. In no case, however, shall the sausage be released from the drying room in less than 25 days from the time the curing materials are added, except that the sausage of the variety known as pepperoni, if in casings not exceeding the size specified, may be released at the expiration of 20 days from the time the curing materials are added. Sausage in casings exceeding 3-1/2” but not exceeding 4” in diameter at the time of stuffing shall be held in a drying room not less than 35 days at a temperature not lower than 45 degrees F., and in no case shall the sausage be released from the drying room in less than 40 days from the time the curing materials are added to the meat.

Method No. 2:

“The meat shall be ground or chopped into pieces not exceeding ¾” in diameter. A dry-curing mixture containing no less than 3-1/3 lbs. of salt to each hundredweight of the unstuffed sausage shall be thoroughly mixed with the ground or chopped meat. After being stuffed, the sausage having a diameter not exceeding 3-1/2” measured at the time of stuffing, shall be smoked not less than 40 hours at a temperature of not lower than 80 degrees F. and finally held in a drying room not less than 10 days at a temperature not lower than 45 degrees F. In no case, however, shall the sausage be released from the drying room in fewer than 18 days from the time the curing materials are added to the meat. Sausage exceeding 3-1/2”, but not exceeding 4” in diameter at the time of stuffing, shall be held in a drying room following the smoking as above indicated, not less than 25 days at a temperature not lower than 45 degrees F., and in no case shall the sausage be released from the drying room in less than 33 days from the time the curing materials are added to the meat.

The USDA and the FSIS

by Barry Bryner

Listeriosis, the infection of listeria monocytogenes (sometimes called “the hot-dog disease”) was responsible for killing twenty-three Canadians during a single incident of food contamination just four years ago! Four separate class-action lawsuits were filed in three provinces. In Ontario alone, the suit is claiming damages of $350 million dollars.

I have to be one of the few people who seem to think that our USDA and FSIS are performing an incredibly difficult task very well. And believe me, I’ve watched them for some time. I've talked to them on the phone and check with them regularly for new rules and innovations. In my opinion, they are performing a remarkable task very well. But, it hasn’t always been that way.

Renown author Upton Sinclair described the filthy conditions of a Chicago meatpacking house in nauseating detail in 1905. His novel clearly defined the safety hazards that the germ-infested, foul, and unsanitary conditions posed to meat consumers everywhere. Sinclair’s publication caused public furor and soon consumers were demanding changes in meat handling and meat products production. Sinclair urged President Theodore Roosevelt to support legislation requiring not only the clean-up of the industry, but the presence of federal inspectors inside all meat-packing houses. The public also insisted that a set of legal guidelines be established for the industry. One year later, both the Food and Drug Act and the Meat Inspection Act were passed. Note that this was not big government pushing legislation down the throats of the consumer. The two new federal acts were the result of public response! The new laws and regulations put many meat packers out of business. Others cleaned up their act. It was an expensive and unparalleled step in the history of the US meat industry.

The United States Department of Agriculture’s “Bureau of Chemistry” enforced the two federal acts until 1927, when the old 1906 Food and Drug Act was reorganized becoming the Food, Drug, and Insecticide Administration. Four years later it became the Food and Drug Administration. Just before World War II, the FDA was transferred from the USDA to the Federal Security Agency – which became the Department of Health and Human Services in 1953. Under the Eisenhower administration, many positive changes were made and new procedures were established, further insuring the health of the public by eliminating many unsanitary practices responsible for meat contamination. Then during the 1950s and 1960s, something totally unprecedented took place. Legally required routine inspection increasingly focused on wholesomeness and visible contamination. At last, the prevalence of animal disease as a food safety problem began to decrease. However, there was yet no legislation protecting the consumer from mislabeling and something we know as “economic adulteration”. And believe me, back then there was plenty of “economic adulteration” in the meat industry. Again, the public spoke up. Again the government responded. I was there and I lived through it. In 1958 the “Food Additive Amendment” was established and for the first time in our history, inspectors had the “teeth” to enforce laws regarding the addition of questionable chemicals including animal drug residues found in meat and poultry products and sausages.

During my college years, the 1967 Wholesome Meat Act was passed. Laws became clearly defined and each state in the Union was required to conduct adequate inspections of America’s meat. Rytek Kutas was very excited about the new legislation and remarked how it made “sloppy meat houses and packing plants finally clean-up”. Throughout the 1970’s, the names of the various inspection agencies were scrambled around a bit and even placed beneath new divisions of the USDA. Finally, in 1977 the Food Safety And Quality Service was established and assigned to the Animal And Plant Health Inspection Service (APHIS) which had been established in 1972. Then on June 17, 1981, the Food Safety And Quality Service was renamed the “Food Safety and Inspection Service” (today’s FSIS).

In 1993, an outbreak of E. coli O157:H7 occurred in the Pacific Northwest. It killed four persons and caused the illness of another 400! Again the public rallied and demanded change for safer ground beef products – including hot dogs! The FSIS responded by increasing more “science-based” testing rather than relying upon the old organoleptic methods of inspection (involving sight, touch, and smell). The FSIS established the first HACCP or “Hazard Analysis and Critical Control Point” system of meat inspection and during the summer of 1996, new laws regarding the prevention and reduction of microbial pathogens in raw meat products took effect. In 2000, further legislation beefed up the enforcement of these new laws. Today more than 9,000 meat processing plants in the United States are regularly inspected for microbial pathogens in meat - (6,500 federally-inspected and 2,550 state-inspected meat and poultry slaughtering and processing plants). Our national Center For Disease Control has attributed the implementation of the new laws as the primary factor responsible for the decline of bacterial food-borne illness in our country since 1996. Incredible as it seems, all pork found in retail stores is either USDA inspected for wholesomeness or inspected by state systems which have standards equal to the federal government. Each animal and its internal organs are inspected for signs of disease. Now that’s something that simply has not taken place historically – especially using today’s microbial detection savvy and equipment.