Why are we still stuck with pasteurization?

The world is increasingly focused on energy efficiency, but I believe we are ignoring milk. All the milk produced is heated and then cooled. I think this should be a significant contributor to global warming. In most households this process is done using fossil fuels, so it not only produces CO2 but also converts all energy to heat energy.

I think UV is a clear answer to this. People have accepted the technology in Water Purifiers and stopped boiling water. So why not milk? What are this technology's limitations? All other related topics I read are quite outdated.

Pasteurized vs. Homogenized Milk: What's The Difference?

You've heard the terms before, but do you really know what "pasteurized" and "homogenized" mean when it comes to milk? The processes are critical to both your safety and your taste buds, but are dramatically different. Having just examined the pros and cons of raw milk, we think nothing could be more important than understanding our food and knowing exactly how it gets to our table. With the amount of dairy we've consumed in our lifetime, we believe it's high time we all understood what goes into our milk.

So what's the difference and why should we care? Put simply, pasteurization is intended to make milk safer and government agencies claim it doesn't reduce nutritional value, while raw milk enthusiasts disagree. Homogenization isn't meant for safety, but for rather for consistency and taste.

Pasteurization is the process of heating milk up and then quickly cooling it down to eliminate certain bacteria. For effective pasteurization, milk can be heated up to 145 degrees Fahrenheit for 30 minutes, but this method isn't very common. More common is heating milk up to at least 161.6 degrees Fahrenheit for 15 seconds, which is known as High-temperature Short-Time (HTST) pasteurization, or flash pasteurization. This method will keep milk fresh for two to three weeks. Then there's Ultra-Heat Treatment (UHT), whereby milk is heated to 280 degrees Fahrenheit for a minimum of two seconds. This processing results in a shelf life that can extend up to nine months. Milk treated with pasteurization or HTST is labeled as "pasteurized," while milk treated with UHT is labeled as "ultra-pasteurized."

Pasteurization does not kill all micro-organisms in milk, but is intended to kill some bacteria and make some enzymes inactive. While raw milk activists claim otherwise, the FDA and the Centers for Disease Control and Prevention (CDC) states that "pasteurization does not reduce milk's nutritional value." While the CDC acknowledges that pasteurization inactivates certain enzymes and reduces certain vitamins like Vitamin C, it argues that "milk is not a major source of Vitamin C" in the U.S. diet.

Raw milk enthusiasts, on the other hand, tout Vitamin C as a benefit of unpasteurized milk, which they claim is more nutritious and contains no additives. The FDA and CDC warn against the dangers of unpasteurized milk and in some states, selling it directly to consumers is illegal. Other states allow the sale of unpasteurized milk directly to consumers, but could have strict laws for distributing the item across states lines.

Homogenization is an entirely separate process that occurs after pasteurization in most cases. The purpose of homogenization is to break down fat molecules in milk so that they resist separation. Without homogenization, fat molecules in milk will rise to the top and form a layer of cream. Homogenizing milk prevents this separation from occurring by breaking the molecules down to such a small size that they remain suspended evenly throughout the milk instead of rising to the top.

Homogenization is a mechanical process and doesn't involved any additives. Like pasteurization, arguments exist for and against it. It's advantageous for large-scale dairy farms to homogenize milk because the process allows them to mix milk from different herds without issue. By preventing cream from rising to the top, homogenization also leads to a longer shelf life of milk that will be most attractive to consumers who favor milk without the cream layer. This allows large farms to ship greater distances and do business with more retailers. Finally, homogenization makes it easier for dairies to filtrate out the fat and create two percent, one percent and skim milk. WiseGeek explains that while it is also possible to achieve these different fat contents by skimming cream from the top, homogenization makes the process more precise. Some people worry, however, that by reducing the size of fat molecules, homogenization makes fat easier to absorb. Studies remain inconclusive on that matter, however.

Why does organic milk last so much longer than regular milk?

Craig Baumrucker, professor of animal nutrition and physiology at Pennsylvania State University, pours out an answer:

If you&rsquove ever shopped for milk, you&rsquove no doubt noticed what our questioner has: While regular milk expires within about a week or sooner, organic milk lasts much longer&mdashas long as a month.

So what is it about organic milk that makes it stay fresh so long?

Actually, it turns out that it has nothing to do with the milk being organic. All "organic" means is that the farm the milk comes from does not use antibiotics to fight infections in cows or hormones to stimulate more milk production.

Organic milk lasts longer because producers use a different process to preserve it. According to the Northeast Organic Dairy Producers Alliance, the milk needs to stay fresh longer because organic products often have to travel farther to reach store shelves since it is not produced throughout the country.

The process that gives the milk a longer shelf life is called ultrahigh temperature (UHT) processing or treatment, in which milk is heated to 280 degrees Fahrenheit (138 degrees Celsius) for two to four seconds, killing any bacteria in it.

Compare that to pasteurization, the standard preservation process. There are two types of pasteurization: "low temperature, long time," in which milk is heated to 145 degrees F (63 degrees C) for at least 30 minutes*, or the more common "high temperature, short time," in which milk is heated to roughly 160 degrees F (71 degrees C) for at least 15 seconds.

The different temperatures hint at why UHT-treated milk lasts longer: Pasteurization doesn&rsquot kill all bacteria in the milk, just enough so that you don't get a disease with your milk mustache. UHT, on the other hand, kills everything.

Retailers typically give pasteurized milk an expiration date of four to six days. Ahead of that, however, was up to six days of processing and shipping, so total shelf life after pasteurization is probably up to two weeks. Milk that undergoes UHT doesn&rsquot need to be refrigerated and can sit on the shelf for up to six months.

Regular milk can undergo UHT, too. The process is used for the room-temperature Parmalat milk found outside the refrigerator case and for most milk sold in Europe.

So why isn&rsquot all milk produced using UHT?

One reason is that UHT-treated milk tastes different. UHT sweetens the flavor of milk by burning some of its sugars (caramelization). A lot of Americans find this offensive&mdashjust as they are leery of buying nonrefrigerated milk. Europeans, however, don&rsquot seem to mind.

UHT also destroys some of the milk&rsquos vitamin content&mdashnot a significant amount&mdashand affects some proteins, making it unusable for cheese.

There are, of course, lots of reasons people buy organic milk. But if it's the long shelf life you're after, I would recommend you buy nonorganic UHT milk and avoid being charged double.

Microbiology the Contributions of Jenner and Pasteur

Edward Jenner was a scientist sometimes known as the Father of Immunology. Jenner’s biggest contribution to the world of immunology was his vaccine against smallpox. In the late 1700’s Jenner noticed that milkmaids did not contract smallpox, a deadly disease that killed one out of every three people and also left survivors maimed.

Jenner was not only a scientist he was a physician who after training to become a doctor spent time as an army surgeon. He then went on to spend his time as a country doctor in England. His research into smallpox came from his case studies and clinical observations that he made. Jenner’s research ended up preventing him from running his regular medical practice, but he received monetary support from colleagues and Parliament in order to continue his research.

Jenner observed that pus from blisters in milkmaids who developed the less deadly cowpox was somehow protecting these women from the more virulent smallpox. In 1796, Jenner tested his theory by injecting pus from cowpox into an eight-year-old boy’s two arms. The boy was inoculated again and later tested, but showed no signs of disease. Jenner himself coined the word vaccination, after his work with cowpox was so successful against smallpox.

Louis Pasteur was a chemist and microbiologist who solved some of the greatest mysteries of microbiology. He worked with anthrax, rabies, chicken cholera and diseases in silkworms and helped to contribute to the development of many vaccines. Pasteur also described the scientific method for fermentation and the brewing of beer. Through his research, Pasteur discovered that microorganisms were responsible for the fermentation process. He also discovered that the growth of some organisms led to the spoiling of milk, wine and beer. He soon found a way of heating liquids that disposed of these microorganisms and thus to the process of Pasteurization.

Later, Pasteur worked with chicken cholera, finding that a weakened source of the cholera bacteria did not cause the disease in the chickens. By inoculating other chickens with the bacteria, he found they got slightly ill, but recovered. He followed this work up with his anthrax work with cattle. Pasteur found that by treating the anthrax bacteria with oxygen, its virulence decreased. Pasteur called his altered forms of bacteria, vaccines.

Pasteur used his rabies “vaccine” on a small child who had been bitten by a rabid dog. Although he was taking a great chance, he knew that without his “vaccine” the child would probably die. Pasteur’s vaccine was a success and the child did not get rabies. After the success of the boy’s treatment, the first of Pasteur’s institutes was built. The success also laid the groundwork for other successful vaccines.

How Pasteurization Works

It's not just a simple case of heat stroke. To understand what heat does to a bacterium, we need to know about its structure. A bacterium is a single-celled organism. Think of it like a studio apartment, one room containing all the things a person needs to live: food, water, air. The walls of the apartment enclose the electrical wiring and gas pipes that deliver energy, along with the sewage pipes that get rid of waste products. In contrast to the size of this single-celled organism, even an animal as small as a mouse would be like a huge city with thousands of buildings and extensive infrastructure to keep it "alive."

In more scientific terms, a bacterium is made up of the cell envelope, the cytoplasm and, often, the flagella. Besides holding in the cytoplasm, the cell envelope is where energy-generating functions like photosynthesis and respiration happen. The cytoplasm refers to everything inside the cell envelope, a mixture of water, ribosomes, chromosomes, nutrients and enzymes -- all the things that keep the bacterium alive and kicking. Enzymes are especially important because they cause the chemical reactions that make up the cell's metabolism. The flagella are tiny appendages on the outside of the bacterium that help it move around, attach to surfaces or fend off enemies.

Now that we've set the scene and introduced the characters, here comes the dramatic climax. When the temperature gets hot enough, the enzymes in the bacterium are denatured, meaning they change shape. This change renders them useless, and they're no longer able to do their work. The cell simply ceases to function.

Heat can also damage the bacterium's cell envelope. Proteins and fatty acids making up the envelope lose their shape, weakening it. At the same time, fluid inside the cell expands as the temperature rises, increasing the internal pressure. The expanding fluid pushes against the weakened wall and causes it to burst, spilling out the guts of the bacterium.

Thermoduricbacteria are more heat-resistant and harder to kill. In terms of our apartment analogy, thermoduric bacteria have reinforced walls, double-paned windows, insulated pipes and an emergency supply of water and food. These heat-defying bacteria have to be kept under control by refrigeration, which keeps them from multiplying. [source: Todar]

Not all types of bacteria are harmful. "Friendly" bacteria like Lactobacillus,Bifidobacterium and Saccharomyces cerevisiae take up residence in the human gut and crowd out the harmful bacteria. Beneficial bacteria are the same ones used to ferment and culture foods. These helpful microorganisms also keep the gut healthy in part by digesting fiber to produce food for the cells that line the intestines. Healthy intestines do a better job of digesting food and are a crucial part of the human immune system because they keep out pathogens but let in nutrients. Foods rich in probiotic bacteria include yogurt, kefir, cultured butter and raw sauerkraut.

A Working Model

Today, the most popular theory for biological homochirality includes all of these conclusions. Physical phenomena such as polarized light and electroweak force create a slight imbalance of D- and L-isomers. This small discrepancy is amplified into a more uneven imbalance by autocatalysis. Then, once life was formed, a single isomer was selected for quickly by the food chain and the specificity of enzymes. Thus, today we only see L-amino acids and D-sugars.

This theory still has some holes. There may never be a perfect explanation for an event that began billions of years ago. But we now have at least a potential solution for the mystery of biolgical homochirality.

“Mystery creates wonder, and wonder is the basis of man’s desire to understand.” — Neil Armstrong

For more posts about disease and biology, subscribe to Cell Your Soul. Feel free to comment below or message your feedback!

The No. 1 Reason Why Vaccine Reactions Vary, Doctors Say

This is why COVID vaccine side effects range so widely from one person to another.


As the COVID vaccine rollout continues across the country, you've likely noticed how differently people have reacted to their shots—whether they're made by Johnson & Johnson, Pfizer-BioNTech, or Moderna. Some individuals experience side effects that have them stuck in bed for a day or two and others seem to experience nothing at all. So, what does it mean if you're on one end of the spectrum or somewhere in the middle? Keep reading to find out the key reason behind recipients' varying vaccine reactions, and for more vaccine news, This Vaccine Side Effect Could Mean You Already Had COVID, New Study Says.


In an article for The Conversation, Robert Finberg, MD, a professor of medicine at the University of Massachusetts Medical School, explains that your body develops two responses to a vaccine: the initial response is called the innate immune response, but it's the later response, called the adaptive immune response, that helps protect you should you come into contact with the virus later. "The long-lasting adaptive immune response … relies on your immune system's T and B cells that learn to recognize particular invaders, such as a protein from the coronavirus. If the invader is encountered again, months or even years in the future, it's these immune cells that will recognize the old enemy and start generating the antibodies that will take it down," he explains.

As far as how well your body develops these T and B cells, Mark Loafman, MD, told NBC 5 Chicago recently that vaccine reactions are "really just kind of a reflection of how unique each of our systems are." "Each of our immune systems is a mosaic composite of all that we've been through and all that we have and all we've recently been dealing with," he explained. "Our individual response varies. Everybody gets the appropriate immune response."


Chris Thompson, MD, an immunologist and associate professor of biology at Loyola University Maryland, told Healthline people react differently to vaccines for a variety of reasons. He said factors such as health, genetics, nutrition, age, gender, preexisting immunity, environment, and use of anti-inflammatory medicines can all be connected to vaccine reactions. "Even if you don't feel crummy after your vaccines, chances are your body still had a good, protective immune response," Thompson explained.

A 2013 study published in the scientific journal Cell found evidence that suggests genetics play a role in our body's immune response. The researchers looked at approximately 8.2 million gene variants in blood samples taken from 1,629 people in Sardinia, Italy. The SardiNIA researchers found 89 independent gene variants and 53 sites linked to regulating immune system cell production. " From this study, we wanted to know the extent to which relative immune resistance or susceptibility to disease is inherited in families," said, David Schlessinger, PhD, a study author and chief of the Laboratory of Genetics at the National Institute of Aging (NIA). "If your mother is rarely sick, for example, does that mean you don't have to worry about the bug that's going around? Is immunity in the genes? According to our findings, the answer is yes, at least in part."

And for more COVID news delivered right to your inbox, sign up for our daily newsletter.


The most common side effects of the COVID vaccine range from pain, redness, and swelling in the injection site, to tiredness, headache, muscle pain throughout the body, chills, fever, and nausea, according to the Centers for Disease Control and Prevention (CDC). But whether you experience one of these side effects mildly or all of them severely, that doesn't mean the vaccine worked worse or better. Anna Wald, MD, an infectious diseases physician, recently told HuffPost that the vaccine's effectiveness is "unlikely to be determined by how severe your side effects are," the news outlet reported.

In his article for The Conversation, Finberg wrote: "Scientists haven't identified any relationship between the initial inflammatory reaction and the long-term response that leads to protection. There's no scientific proof that someone with more obvious side effects from the vaccine is then better protected from COVID-19. And there's no reason that having an exaggerated innate response would make your adaptive response any better."

And for a more on why certain people are hit harder by the vaccine's side effects, check out This Is Why Half of People Have Stronger Vaccine Side Effects, CDC Says.


In answering a Q&A with, Amy Ray, MD, a director at MetroHealth, said people should not "use the presence or absence of side effects as 'proof' of immunity." "If you don't have side effects, it doesn't mean your immune system isn't working," James Fernandez, MD, an allergy and immunology expert, told the news outlet. "I wouldn't focus on those early side effects related to the vaccine to judge whether you had an [effective] response or not."

Kelly Elterman, MD, a board-certified anesthesiologist in San Antonio, Texas, also explained in a recent article for GoodRx that a lack of side effects doesn't correlate with decreased immunity. "Only about 50 percent of people vaccinated with either the Pfizer or Moderna vaccines experienced side effects other than arm pain, while 95 percent were protected from COVID-19 infection," Elterman wrote. Additionally, less than half of Johnson & Johnson recipients developed side effects other than pain at the injection site, "while up to 74 percent were protected from COVID-19 infection."

And if you're curious as to how long your vaccine works for, Dr. Fauci Says Your COVID Vaccine Protects You For This Long.

Why Frankenstein Is Still Relevant, Almost 200 Years After It Was Published

Fabrice Coffrini/AFP/Getty Images

Can I be totally honest? All I remember about Frankenstein is that Frankenstein is the doctor, not the monster. What happens in it?

That’s harder to answer than you would think, because the book is studded with framing details and seemingly extraneous characters, but it goes something like this: Victor Frankenstein is a rich Genevan who shows great promise in scientific research. After his mother’s death, he somehow figures out how to endow dead flesh with life, but the being he makes is nightmarishly ugly, so he abandons it. In the wilderness, it manages to educate itself, becoming an astute thinker but also coming to resent its creator.

Soon enough, the man-made monster begins to take revenge on Frankenstein by lashing out at his loved ones, a process that only accelerates after the scientist fails to meet the creature’s (relatively civil) demands. Before long, almost everyone is dead, everything’s on fire, and Frankenstein and his creature are chasing each other across the Arctic on sleds.

Wait, the Arctic?

OK, fine. I get that this book is important, but why are we talking about it in a series about emerging technology?

Though people still tend to weaponize it as a simple anti-scientific screed, Frankenstein, which was first published in 1818, is much richer when we read it as a complex dialogue about our relationship to innovation—both our desire for it and our fear of the changes it brings. Mary Shelley was just a teenager when she began to compose Frankenstein, but she was already grappling with our complex relationship to new forces. Almost two centuries on, the book is just as propulsive and compelling as it was when it was first published. That’s partly because it’s so thick with ambiguity—and so resistant to easy interpretation.

Is it really ambiguous? I mean, when someone calls something frankenfood, they aren’t calling it “ethically ambiguous food.”

It’s a fair point. For decades, Frankenstein has been central to discussions in and about bioethics. Perhaps most notably, it frequently crops up as a reference point in discussions of genetically modified organisms, where the prefix Franken- functions as a sort of convenient shorthand for human attempts to meddle with the natural order. Today, the most prominent flashpoint for those anxieties is probably the clustered regularly interspaced short palindromic repeats, or CRISPR, gene-editing technique. But it’s really oversimplifying to suggest Frankenstein is a cautionary tale about monkeying with life.

As we’ll see throughout this month on Futurography, it’s become a lens for looking at the unintended consequences of things like synthetic biology, animal experimentation, artificial intelligence, and maybe even social networking. Facebook, for example, has arguably taken on a life of its own, as its algorithms seem to influence the course of elections. Mark Zuckerberg, who’s sometimes been known to disavow the power of his own platform, might well be understood as a Frankensteinian figure, amplifying his creation’s monstrosity by neglecting its practical needs.

But this book is almost 200 years old! Surely the actual science in it is bad.

Shelley herself would probably be the first to admit that the science in the novel isn’t all that accurate. Early in the novel, Victor Frankenstein meets with a professor who castigates him for having read the wrong works of “natural philosophy.” Shelley’s protagonist has mostly been studying alchemical tomes and otherwise fantastical works, the sort of things that were recognized as pseudoscience, even by the standards of the day. Near the start of the novel, Frankenstein attends a lecture in which the professor declaims on the promise of modern science. He observes that where the old masters “promised impossibilities and performed nothing,” the new scientists achieve far more in part because they “promise very little they know that metals cannot be transmuted and that the elixir of life is a chimera.”

Is it actually about bad science, though?

Not exactly, but it has been read as a story about bad scientists.

Ultimately, Frankenstein outstrips his own teachers, of course, and pulls off the very feats they derided as mere fantasy. But Shelley never seems to confuse fact and fiction, and, in fact, she largely elides any explanation of how Frankenstein pulls off the miraculous feat of animating dead tissue. We never actually get a scene of the doctor awakening his creature. The novel spends far more dwelling on the broader reverberations of that act, showing how his attempt to create one life destroys countless others. Read in this light, Frankenstein isn’t telling us that we shouldn’t try to accomplish new things, just that we should take care when we do.

This speaks to why the novel has stuck around for so long. It’s not about particular scientific accomplishments but the vagaries of scientific progress in general.

Does that make it into a warning against playing God?

It’s probably a mistake to suggest that the novel is just a critique of those who would usurp the divine mantle. Instead, you can read it as a warning about the ways that technologists fall short of their ambitions, even in their greatest moments of triumph.

Look at what happens in the novel: After bringing his creature to life, Frankenstein effectively abandons it. Later, when it entreats him to grant it the rights it thinks it deserves, he refuses. Only then—after he reneges on his responsibilities—does his creation really go bad. We all know that Frankenstein is the doctor and his creation is the monster, but to some extent it’s the doctor himself who’s made monstrous by his inability to take responsibility for what he’s wrought.

OK, hold up. I’m paging through the book now, and this is how Shelley has Frankenstein describe his creation: “yellow skin,” “watery eyes,” “shriveled complexion,” “straight black lips.” Plus, it’s like 8 feet tall. That sure sounds like a description of a monster.

What matters most there isn’t the creature’s terrifying appearance but how poorly the doctor responds to it. In his essay “The Monster’s Human Nature,” the evolutionary biologist Stephen Jay Gould argues that there’s nothing fundamentally wrong with Frankenstein’s goals. Instead, Gould writes, “Victor failed because he followed a predisposition of human nature—visceral disgust at the monster’s appearance—and did not undertake the duty of any creator or parent: to teach his own charge and to educate others in acceptance.”

In other words, Frankenstein stumbles as a science educator, not as a scientist. Some academic critics have taken issue with that reading, arguing that the bad doctor’s faults run far deeper. But it may still be helpful to reckon with the connection between Frankenstein and Adam, a man given stewardship over the creatures of the earth. Shelley’s protagonist is monstrous because he doesn’t take his own similar responsibility seriously. The book’s subtitle—The Modern Prometheus—also contains an important mythological clue: Prometheus brings fire to the mortals and unleashes dire consequences in the process, granting them the ability to burn down the world.

That last association is fitting, since Frankenstein is, to some extent, a story about the unintended consequences of our actions. That angle on the book has helped turn it into a prop for those driven by anti-scientific skepticism, an interpretation of the text that’s been circulating for decades at the least—probably much longer. It’s been especially central to debates around genetic engineering, for example. There and in other contexts, it’s often colloquially cited (“You’re going to create a Frankenstein’s monster!”) to cut off scientific inquiries before they even begin. Indeed, as Romanticism scholar Richard Holmes has suggested, though many describe Frankenstein as the first major work of science fiction, we should also recognize it as “one of the most subversive attacks on modern science ever written.” For all that, Shelley spends far more of her book worrying over inadequate parenting than railing against bad science.

The 2013 United States Food and Drug Administration Food Code defines regular shell eggs as a potentially hazardous food, i.e., “a food that requires time/temperature control for safety (TCS) to limit pathogenic microorganism growth or toxin formation.” [1]

All egg products sold in the U.S that are pasteurized due to the risk of food-borne illnesses are done per U.S. Department of Agriculture rules. They also do not allow any egg products to be sold without going through the process of pasteurization. They also do not recommend eating shell eggs that are raw or undercooked due to the possibility that Salmonella bacteria may be present. [2]

Because of the risk of food-borne illness caused by Salmonella bacteria that may be present in raw eggs, the U.S. Department of Agriculture requires a safe-handling advisory statement on all packages of raw shell eggs that are not treated to destroy Salmonella as follows: "Safe Handling Instructions: To prevent illness from bacteria: Keep eggs refrigerated, cook eggs until yolks are firm, and cook foods containing eggs thoroughly." [2]

Salmonellosis Edit

The primary risk associated with eggs is food-borne illness caused by Salmonella enteritidis bacteria. Salmonella enteritidis is a dangerous bacterium that can be transferred to humans through ingestion of raw or undercooked eggs. [3] Nearly four out of five Salmonella-related foodborne illness cases share a common vehicle: raw or undercooked shell eggs. [3]

Salmonellosis, the illness that a Salmonella infection causes, is characterized by nausea, vomiting, abdominal cramps, diarrhea, fever, and headache. The onset of its symptoms begins between six hours and 72 hours after the consumption of food contaminated with Salmonella bacteria. [4] As few as 15 bacterial cells can cause food-borne illness. [2]

While the Centers for Disease Control and Prevention estimate there are one million cases of salmonellosis per year in the US leading to 19,000 hospitalizations and 380 deaths, [5] the U.S. Food and Drug Administration (FDA) estimates that only 79,000 cases each year are the result of consuming eggs contaminated with Salmonella, of which only 30 result in death. [6]

In Europe, all hens are required to be vaccinated against salmonellosis. Eggs are not washed (and, in some countries, not refrigerated) since condensation could lead to salmonellosis contamination. [7] In the US, it is important to keep eggs refrigerated since not all hens are vaccinated.

Avian flu virus Edit

The process of pasteurizing eggs also destroys avian flu virus. [8]

Food code compliance Edit

The 2013 FDA Food Code states that in serving highly susceptible populations (preschool age children older adults individuals with compromised immune systems and individuals who receive meals through custodial care-giving environments such as child or adult day care centers, kidney dialysis centers, hospitals, or nursing homes [5] ):

“Pasteurized eggs or egg products shall be substituted for raw eggs in the preparation of Foods such as Caesar salad, hollandaise or Béarnaise sauce, mayonnaise, meringue, eggnog, ice cream, egg-fortified beverages and recipes in which more than one egg is broken and the eggs are combined.” [3]

The FDA Food Code has gained adoption by health jurisdictions throughout the U.S. [9]

As distinct from whole shell eggs, “egg products” are defined by the U.S. Department of Agriculture as “eggs that are removed from their shells for processing." The processing of egg products includes breaking eggs, filtering, mixing, stabilizing, blending, pasteurizing, cooling, freezing or drying, and packaging. This is done at U.S. Department of Agriculture (USDA)-inspected plants.

Egg products include whole eggs, whites, yolks and various blends with or without non-egg ingredients that are processed and pasteurized and may be available in liquid, frozen, and dried forms. [10] This is achieved by heating the products to a specified temperature for a specified period.

According to the U.S. Department of Agriculture, in-shell pasteurized eggs may be used safely without cooking. For example, they may safely be consumed raw (as in raw cookie dough or eggnog) or in undercooked forms (such as a sunny-side up egg). [2] Many food service and health care providers use these eggs to prevent cross-contamination in their kitchens.

History Edit

By traditional pasteurization methods, heating a raw shell egg to a high enough temperature to achieve pasteurization would also cook the egg. However, beginning in the early 1980s, Dr. James P. Cox and R.W. Duffy Cox of Lynden, Washington, began developing methods to pasteurize shell eggs.

In the early 1990s, the Coxes were introduced to L. John Davidson. Davidson recognized the market need and opportunity for a safer egg option for consumers and food operations around the country. Davidson acquired a license agreement on the technology from the Cox Family and formed Pasteurized Egg Corporation to introduce safe egg technology to the consumer marketplace.

The process for pasteurizing shell eggs has been patented. [11] [12] Currently, National Pasteurized Eggs Inc. of Lansing, Illinois, owns Dr. Cox's patent to the pasteurization process. Only National Pasteurized Eggs Inc. can provide pasteurized shell eggs produced through these patented processes. The eggs can be found in all U.S. states under the brand Davidson's Safest Choice®, introduced in 2003. [13]

Process Edit

Pasteurizing eggs in their shells is achieved through a technique that uses precise time and temperature zones within water baths. [14] [15] Pasteurizing eggs in their shells can also be achieved through a process that involves treatment with ozone and reactive oxygen species under high and low pressures, followed by replacement with an inert gas, such as nitrogen.

Currently, shell eggs pasteurized using the heating technique are the only commercially available pasteurized eggs. [16] According to the U.S. Department of Agriculture,

Shell eggs can be pasteurized by a processor if FDA accepted the process for the destruction of Salmonella. Pasteurized shell eggs are now available at some grocery stores and must be kept refrigerated to retain quality. The equipment to pasteurize shell eggs isn't available for home use, and it is very difficult to pasteurize shell eggs at home without cooking the contents of the egg. [2]

After pasteurization, the eggs are coated with food-grade wax to maintain freshness and prevent environmental contamination and stamped with a blue or red "P" in a circle to distinguish them from unpasteurized eggs.

Quality Edit

Opinion on the quality of pasteurized shell eggs is mixed, and sometimes depends on whether comparisons involve experimental processes or products that are actually on the market. Taste tests noted deficiencies in pasteurized shell eggs experimentally produced via a microwaved pasteurization process (not for commercially available pasteurized shell eggs). [17] Using commercially available pasteurized shell eggs, a San Francisco Chronicle reporter noted a "slight chemical taste" for pasteurized shell eggs, [18] and a Lifescript blogger noted a "barely detectable" flavor and aroma difference and stated the eggs were "worth" their price. [19] Relish magazine states that pasteurized shell eggs “look like real eggs, act like real eggs and taste like real eggs.” [20] “Independent taste tests conducted in Good Housekeeping kitchens have not been able to tell any differences between raw and pasteurized eggs,” according to Food Safety News, [21] and in two out of three tastings a Chicago Tribune reporter preferred pasteurized eggs flavor over farmers market eggs. [22] According to International Business Times, demand for pasteurized shell eggs within the food service industry is strong because, as of 2008, “states such as California, Iowa, Michigan, Wisconsin and Illinois have adopted the most recent FDA Food Code, in which pasteurized shell eggs shall be substituted for raw eggs to at-risk groups.” [23]

Exemption Edit

The FDA Food Code exempts pasteurized shell eggs from the definition of "time/temperature control for safe food.” [1] [3] requirement to carry a safe handling advisory statement. [2]

How Pasteurization Works

There's a fine line between wine and vinegar. That's what Louis Pasteur discovered in 1856 when an alcohol manufacturer commissioned him to determine what was causing beet root alcohol to sour.

At that time, scientists thought that fermentation was a purely chemical process. Pasteur's research into fermentation led him to the discovery that it was yeast, a living organism, that turned the beet juice into alcohol. Under the microscope, yeast was round and plump. But when the alcohol spoiled, it contained a different microbe that was rod-shaped. Pasteur speculated that this rod-shaped microbe called Mycoderma aceti, which is commonly used to make vinegar, caused the wine to spoil [source: Feinstein].

These discoveries formed the "germ" of Pasteur's germ theory of fermentation. Years later, Pasteur would apply the same concepts to the origins of disease, leading to some of his greatest contributions to science and medicine.

In the meantime, Emperor Napoleon III enlisted Pasteur to save France's wine industry from the "diseases of wine" [source: Lewis]. In previous experiments, Pasteur had discovered that heating the fermented wine would kill the microbes that caused it to spoil. He wasn't the first to see that connection. Nicolas Appert, the inventor of in-container sterilization, also known as canning, had already shown that treating food with heat could preserve it. Pasteur's contribution was to determine the exact time and temperature that would kill the harmful microorganisms in the wine without changing its taste. He patented the process and called it pasteurization. Before long, the process was also used for beer and vinegar.

The pasteurization of milk didn't come into practice until the late 1800s. Back then, tuberculosis was commonly carried by milk. A low-temperature, long-time (LTLT) process, also known as batch pasteurization, was first developed to kill the tuberculosis pathogen. The incidence of tuberculosis contracted from milk fell dramatically, and in fact it no longer makes the Centers for Disease Control and Prevention's list of foodborne illnesses [source: CDC ].

The first commercial milk pasteurizers were produced in 1882, using a high-temperature, short-time (HTST) process. The first law to require the pasteurization of milk was passed in Chicago in 1908 [source: Sun]. Some people didn't like the idea of pasteurizing milk in the beginning, for many of the same reasons that today's raw milk advocates cite [source: Lewis]. We'll talk more later about raw milk and why some people love it and some people hate it.

Louis Pasteur is known as "the father of microbiology." He earned this esteemed title by doing much more than inventing the process of pasteurization. Pasteur's lifetime of discoveries followed a natural arc each project he worked on led him to his next insight. During his research on tartaric acid in his first job as a scientist, he discovered that organic molecules are asymmetrical. Finding organic molecules in beer and wine led him to recognize that microorganisms such as Lactobacillus functioned as the agents of fermentation and food spoilage. This understanding of the role of bacteria helped him to develop his germ theory of fermentation. Years later, he became interested in human disease and applied his knowledge of microorganisms to develop the germ theory of disease. Eventually, he developed the vaccines for chicken cholera, anthrax and rabies.

Watch the video: How To Fix A Stuck Ferment: Help Fermentation Stopped Early! (January 2022).