Back in grade school, Louis Pasteur was one of those names attached to some long-ago discoveries, the explanation of which you just knew was going to re-appear on the final exam. But when you’re 10 years old, it’s pretty tough to appreciate the incredible quantum leap forward that a long-ago dead guy contributed to the progress of humanity, even as you were sucking down a carton of milk at lunch time that wouldn’t have been safe to drink without Pasteur’s ground-breaking research.
He was truly a legend in the long, 1,000-year war by which science finally supplanted superstition as the explanation for infectious disease, a remarkably gifted researcher who —literally — wrote the book on microbial pathogens: “Germ Theory and Its Applications to Medicine & On the Antiseptic Principle of the Practice of Surgery,” for which his co-author was Joseph Lister, the British physician who pioneered the concept of antiseptic surgery in the 1890s, using carbolic acid to sterilize surgical instruments and cleanse wounds.
Are you kidding me? That would be like Robert DeNiro and Al Pacino collaborating on a book titled, “How to Create Effective Characterization in Cinematic Productions.”
Pasteur's phenomenal contributions to microbiology also included the discovery that weakened forms of a microorganism could be used to immunize people against virulent forms of the pathogen, and he developed techniques to vaccinate dogs against rabies,as well as treat humans bitten by rabid dogs.
All that was accomplished in additionto developing pasteurization, the process by which harmful pathogens in perishable foods are inactivatedby using heat below the boiling point, which destroys the microbes without destroying the food product itself.
Being French, of course, Pasteur first applied his theory to wine, demonstrating that heating it to about 130 °F for a few minutes preserved the flavor while ridding the wine of spoilage organisms.His process was soon applied to milk and remains to this day the keyto the production and marketing of the dairy products that we simply take for granted are totally safe to consume without any food-safety concerns beyond occasionally sniffing that expired carton of 2% in the back of the fridge and realizing that its time has come and gone.
The advent of new technology
Why is all this relevant? Because pasteurization, with its incredible potential to impact food safety, may soon be coming to the meat and poultry industries.
Just this week, the North American Meat Processors Association petitioned USDA to allow the term “Pasteurized” to be used for labeling qualified meat and poultry products, according to NAMP’s science advisor, Jim Marsden, Ph.D., a Kansas State University Distinguished Professor of Meat Science and Associate Director of the National Agriculture Biosecurity Center at KSU.
But how is it possible to pasteurize non-liquid foods, since the primary method of treatment has always been the use of heat?
“The idea behind pasteurization is not to sterilize a food, but to eliminate the risk of most pathogenic bacteria,” Marsden wrote on his Meatingplace blog.“Many other food products are pasteurized, including crab meat, shell fish and eggs, which is possible because of advances in antimicrobial and packaging technologies.”
In fact, meat products such as ham, turkey breasts and roast beef can be cooked — pasteurized — in the bag in which they’re packaged or cooked and then reheated in consumer packages to eliminate microbial contaminants. Those products become pasteurized exactly the same as pasteurized milk, Marsden stated.
Of course, beginning about 20 years ago, the meat industry embarked on an ill-fated attempt to re-define post-processing irradiation as “pasteurization,” a marketing concept that was gunned down by a coalition of food and consumer group activists who managed to portray the technology as an offshoot of the deadly and dangerous nuclear power industry.
Their campaign didn’t discredit the concept of pasteurization, but it certainly “de-linked” Pasteur’s wonderfully effective process from the possibility of appearing on the labels of raw meat and poultry products treated with gamma irradiation.
However, that was then, and now other useful technologieshave emerged, including ultraviolet light, steam and hot water treatments, microwaving, ultrasound and certain chemical applications. Another promising technique that inactivates both pathogenic and spoilage microorganisms is high pressure processing.According to Marsden, HPP can pasteurize both raw and cooked meat and poultry products and is already being widely used on pre-sliced deli meats and similar cooked products.
That’s not all. The ultimate challenge, especially for the beef industry, has been eliminating the contamination of carcasses with pathogens such as E. coli O157:H7 that eventually find their way into raw ground beef and even whole-muscle meats sold fresh to consumers. Marsden, however, believes that even carcasses can be pasteurized.
“Since contamination works its way from the outside of carcasses, it should be possible to eliminate contamination on carcass surfaces through the application of heat and other anti-microbial treatments,” he stated.
Assuming USDA approves NAMP's petition, the meat industry could one day soon enjoy a leap forward in food safety as dramatic — and historic — as Pasteur’s original experiments on those casks of French wine.
Dan Murphy is a veteran food-industry journalist and commentator