Tag Archives: milk

A milk peptide could lead us to new, non-addictive sleep medication

A new study highlights that certain elements in casein tryptic hydrolysate (CTH), a mixture of protein elements that are naturally produced from the digestion of milk, could form the basis of new sleep remedies.

Image via Pixabay.

The calming, rest-inducing effect of a glass of warm milk before bedtime is already well known. Researchers ascribe this mostly to tryptophan, an amino acid present in milk. However, new research suggests that this isn’t the only compound in milk that helps us sleep. A mixture of peptides (the building blocks of proteins) collectively known as CTH, which is also present in milk, also seems to have such an effect.

New research zooms in on the issue more closely, identifying which specific peptides in CTH produce this effect. Such molecules could be used to create novel, all-natural treatments for sleep disorders, the study explains.

Milk for sleep

Insomnia is quite a serious issue on a global level. Different sources estimate that between 10% and 30% of adults worldwide suffer from chronic insomnia, although some estimates place it as high as 50% or even 60%. Since lack of sleep can quickly become a debilitating issue, doctors often prescribe sedatives to help their patients get some shut-eye. The most common drugs used for this purpose are benzodiazepines and zolpidem (brand name Ambien).

They do their job well, but the side effects can become very uncomfortable, even debilitating in their own right. Both of these sedatives are also quite addictive. So any alternatives to these treatments would be welcome, for both doctors and patients.

Many sedatives today work by activating the GABA receptor in the brain — this is a receptor site that, once bound, reduces anxiety and enhances sleep. The interaction between the casein in cow’s milk with trypsin, a digestive enzyme present in the human stomach, produces a peptide complex known as CTH. A specific element in this mixture, α-casozepine (α-CZP), has previously been identified as interacting with the GABA receptor. Starting from this background, the authors wanted to see if other peptides in this complex can produce similar or greater sleep-enhancing effects.

The authors used mass spectrometry to identify other peptides with bioactive properties released from CTH during a simulated gastric process (simulated digestion). They then virtually estimated their potential to pass through the blood-brain barrier and tie to the GABA site. The most promising candidates were then tested in live mice.

One, in particular, christened YPVEPF, had a very encouraging effect. Compared to mice in the control group, 25% of those who were administered YPVEPF fell asleep more quickly. Mice in the experimental group also slept on average more than 4 times as much as those in the control group.

Considering the efficacy YPVEPF showed in mice, the team hopes to carry on investigating its potential in human subjects. Eventually, they hope, it will form the basis for new, non-addictive drugs meant to tackle sleep disorders. They also advise that other promising peptides in the CTH complex be investigated further, especially those that can produce sleep-enhancing effects through pathways other than the GABA receptor.

The paper “Identification and Screening of Potential Bioactive Peptides with Sleep-Enhancing Effects in Bovine Milk Casein Hydrolysate” has been published in the Journal of Agricultural and Food Chemistry.

The dairy industry today is much cleaner and more efficient than 60 years ago

Producing dairy today is cleaner than it was 50 years ago, a study finds.

Image credits Ulrike Leone.

Each liter of California milk requires less land, water, and releases fewer emissions than in 1964 to produce, reports a new study from the University of California, Davis. The study takes into account inputs as producing feed for the animals, the animals themselves, as well as the machinery and transportation needed to produce milk.

California is the top dairy-producing state, and milk production is the third-largest agricultural industry in the US.

Udder progress

“We compared 1964 through 2014 and found a 50 percent reduction in greenhouse gases to produce the same quantity and quality of milk,” said senior author Ermias Kebreab, professor and Sesnon Endowed Chair in the Department of Animal Science at UC Davis. “The magnitude of change is surprising.”

A life cycle environmental assessment of California cows, from the time they’re born until they leave the farm, suggests that modern agricultural advancements really do help slash emissions and the environmental footprint of our food. The study included an analysis of inputs such as the feed, machinery, and transportation required to produce milk. The figures were then compared to their equivalents from 1964.

The largest cut to methane emissions seen in the study came from a decline in enteric methane — basically, cow belches. Reductions in emissions from manure were also recorded, but they were less dramatic than enteric ones.

“Reductions in enteric methane intensity (i.e., methane emissions per gallon of milk) are primarily a result of better genetics and breeding and better nutrition for the animals,” said Kebreab.

Overall, water use in the industry overall dropped by 88% compared to 1964 levels, the team explains, primarily through more efficient water use in feed crops and the use of by-products such as almond hulls for feed. Water use in housing and milking also dropped by 55%. Land use per liter of milk has also decreased, mostly through the introduction of better crops and agricultural practices.

While per liter efficiency has definitely increased, total greenhouse gas emissions from cows in California has increased, as more animals are being reared today. The team notes, though, that a cow in the 1960s could produce about 4,850 kilograms of milk per year, while one today can produce over 10,000 kg annually.

“There is a lot of discussion about how cows have a huge environmental footprint, but no one is talking about how the dairy industry has changed,” said Kebreab. “Dairy farmers are doing a lot to help reduce the industry’s environmental footprint.”

On the one hand, I definitely find the results encouraging, and I applaud the farmers that are doing their part to clean up the industry. But at the end of the day, there’s only so much they can clean. In the context of climate change, the most effective choice is simply to not breed any more cows. But I do love cheese, and I’m quite a fan of meat, so I secretly hope that we’ll be able to still put these on the table and safeguard the health of ecosystems around the world. In a previous study, Kebreab found that feeding dairy cows a small amount of Asparagopsis armata seaweed along with their feed, reduced methane emissions by up to 60% — so maybe there is still hope.

The paper “Greenhouse gas, water, and land footprint per unit of production of the California dairy industry over 50 years” has been published in the Journal of Dairy Science.

America’s largest milk producer filed for bankruptcy. Are plant-based alternatives to blame?

Dean Foods, America’s largest milk producer, has been around for almost a century. Now, after 94 years, it’s filing for bankruptcy.

Image credits: Mehrshad Rajabi.

When a long-lasting company files for bankruptcy, it’s often due to bad management or internal issues. But the case of Dean Foods, a company with yearly revenues of $7.7 billion, might be a bit different.

The company has struggled more and more in recent years because Americans are drinking less cow milk; oftentimes, they are substituting it with plant-based alternatives like soy, almond, or coconut. This year (2019) has been particularly bad as the company’s sales went down by 7%, and profits went down 14%.

Americans’ per capita consumption milk has decreased by 26% since 2000, according to the U.S. Department of Agriculture. Since 1975, milk consumption per capita has tumbled more than 40%.

It’s not just Dean Foods that got hit. The entire milk market suffered. In 2018, milk sales went down by more than $1 billion in 2018, compared to the previous year.

At the same time, plant-based milk has surged. The global plant-based dairy market was estimated at a value of $11.9 billion as of 2017 and is slated to surpass $21 billion by 2024. So, it’s not just the US — throughout the entire developed world, plant milk is swooping in and quickly replacing “regular” milk as people are looking for ways to phase out animal protein from their diet. In the UK, 25% of adults say plant-based milk is their first option.

Money-wise, plant-based milk is more expensive than regular milk — around two times more expensive in general — but given the overall low cost of milk, it’s a price more and more people can afford.

Modern research is also partially to blame for the decline in milk consumption. Several studies have dented the traditional healthy halo once held by milk, and a recent long-term study actually found that milk can increase the risk of bone fractures and mortality. The high saturated fat content of dairy can raise levels of bad cholesterol and while moderate consumption of dairy can still have a positive impact on healthy diets, people are starting to drop it in favor of plant-based alternatives.

The plant milk market has become quite diverse, with soy, almond, oat, rice, coconut, and cashew being just some of the many alternatives you can find on the shelves and at shops. Soy milk stands out as the healthiest options. It packs as much protein as cow’s milk, without any of the saturated fats. Almond, the most popular dairy alternative, has less protein but is still an overall healthy option.

It’s not just health that’s significant — the environmental and humanitarian aspects are also noteworthy. Milk (and dairy in general) produces substantial greenhouse gas emissions. It requires intensive land use and large quantities of water. Plant-based alternatives produce drastically fewer emissions, they require much smaller land areas, and consume less water than dairy milk.

In addition, most milk production cows are kept in questionable conditions (to put it lightly) and to the dairy industry, male calves are considered surplus — they are either shot after birth or sold to the meat industry. The cheapest option in most cases is to simply shoot the calf — which understandably, many people don’t want to support.

For all these reasons, plant-based milk is starting to take away from the dairy industry. Dean Foods’ failure may or may not be a result of that trend. The fact that Walmart, one of their biggest clients, dropped their services to replace them with their own dairy factory certainly didn’t help. Dean has been hemorrhaging executives as well as cash and their approach to the current situation has been criticized by some.

Dean Foods going bankrupt might have nothing to do with plant-based milk, but this is a cautionary tale to the entire industry: plant milk is here, and it’s here to stay. The market needs to adapt.

Ancient baby feeder.

Tiny, ancient, animal-shaped pots were likely the first baby bottles

A team led by researchers from the University of Bristol reports on the earliest evidence of babies being fed animal milk — and of the ancient equivalent of modern-day baby bottles.

Late Bronze Age feeding vessels from Vösendorf, Austria.
Image credits Enver-Hirsch / Wien Museum.

Chemical analyses, as well as the context these vessels were discovered in, strongly suggest that they were used as baby feeders. The vessels were made from clay and first appeared in Europe around the Neolithic (late stone age, around 5,000 BC). Throughout the Bronze and Iron Ages, these vessels become increasingly more commonplace, the team explains.

Baby munchies

“These very small, evocative, vessels give us valuable information on how and what babies were fed thousands of years ago, providing a real connection to mothers and infants in the past,” says lead author Dr. Julie Dunne from the University of Bristol’s School of Chemistry.

The vessels are quite small — usually small enough that a baby could comfortably grip and hold them. They also have a spout through which liquid can be suckled and, in some of the more eye-catching variants, are shaped like animals or resembling animals. Although this does suggest that they were used as an equivalent of today’s baby bottles, we don’t have any direct evidence of their function. For example, they could very well have been made for the sick or infirm to use.

In order to find out what kind of foods these vessels were used to serve, the team analyzed three examples found in child graves in Bavaria. These vessels were small (about 5-10 cm across) with an extremely narrow spout. Food residues within the vessels showed that they contained ruminant milk (from domesticated cattle, sheep, or goats).

Ancient baby feeder.
Selection of Late Bronze Age feeding vessels from Vienna, Oberleis, Vösendorf, and Franzhausen-Kokoron (from left to right), dated to around 1200– 800 BC.
Image credits Katharina Rebay-Salisbury.

The presence of these specialized vessels in child graves, along with the presence of milk residue inside them, strongly suggests that these were used to feed animal milk to babies — in the place of human milk and/or during weaning onto supplementary foods.

The study represents our closest proven link between these vessels and child feeding. They’re also the most direct evidence of weaning practices we have to date — previously, these were inferred from isotopic analysis of infant skeletons, but that only gave us some bits of the puzzle. As such, the study fleshes out our understanding of breastfeeding and weaning practices, as well as infant and maternal health practices in prehistory.

She continued: “Similar vessels, although rare, do appear in other prehistoric cultures (such as Rome and ancient Greece) across the world,” Dunne explains. “Ideally, we’d like to carry out a larger geographic study and investigate whether they served the same purpose.”

The paper “Milk of ruminants in ceramic baby bottles from prehistoric child graves” has been published in the journal Nature.

Earliest evidence of milk consumption comes from Stone Age Britain

Researchers, led by archaeologists at the University of York, have found the earliest evidence of milk consumption ever observed in the teeth of prehistoric British farmers.

Image credits Myriam Zilles.

The team identified a milk protein called beta lactoglobulin (BLG) in the mineralized dental plaque of seven individuals who lived around 6,000 years ago. The findings will help improve our understanding of when humans developed lactose persistence (LP), the ability to digest lactose in milk. It’s also the earliest confirmed sighting of the BLG molecule so far.

Luckily they didn’t brush their teeth

“The fact that we found this protein in the dental calculus of individuals from three different Neolithic sites may suggest that dairy consumption was a widespread dietary practice in the past,” says lead author Dr. Sophy Charlton, from the Department of Archaeology at the University of York.

Dental plaque, while not something you want to have, can be used to gain insight into the diets of ancient people. The material traps proteins from food, through saliva, which are then mineralized in plaque or tartar. The samples of dental plaque analyzed in this study are the oldest to be investigated for protein content, the team explains.

The Neolithic period in Britain ran from 4,000 to 2,400 BC and saw the transition from hunter-gatherer communities to farming, mostly revolving around the growing of wheat and barley and the domestication of animals such as cows, sheep, pigs, and goats. This time also saw the emergence of complex cultural practices such as the construction of monumental and burial sites.

The remains used in this study come from three different Neolithic sites in England: Hambledon Hill, Hazleton North (both in the south of England), and Banbury Lane (in the East Midlands). Individuals from all three sites had milk proteins from goats, cows, and sheep, suggesting that multiple domesticated species were reared at the same time.

“It would be a fascinating avenue for further research to look at more individuals and see if we can determine whether there are any patterns as to who was consuming milk in the archaeological past — perhaps the amount of dairy products consumed or the animals utilised varied along the lines of sex, gender, age or social standing,” says Dr. Charlton.

Finding these proteins in the ancient teeth is particularly exciting, as previous genetic work has suggested that people living at the time did not yet have the ability to digest lactose.

Overall, it means that the ancient farmers either consumed milk in small amounts or processed it into foods such as cheese (which removes most of the lactose). Lactose persistence, our ability to consume milk into adulthood, was the result of a mutation in the genes encoding production of lactase, which breaks down lactose. How and why we evolved this ability is of quite some interest to researchers, as milk and dairy products played an important part in past diets, as well as those of today — and this study gives us a better idea of when the mutation occurred, the conditions that helped it appear, and how people dealt with lactose intolerance before it.

“Because drinking any more than very small amounts of milk would have made people from this period really quite ill, these early farmers may have been processing milk, perhaps into foodstuffs such as cheese, to reduce its lactose content,” says Dr. Charlton.

“Identifying more ancient individuals with evidence of BLG in the future may provide further insights into milk consumption and processing in the past, and increase our understanding of how genetics and culture have interacted to produce lactase persistence.

The paper “New insights into Neolithic milk consumption through proteomic analysis of dental calculus” has been published in the journal Archaeological and Anthropological Sciences.


New research paints the history of East Africa’s farmers, and how they evolved to eat dairy

New research is looking into how one of the world’s more diverse areas first took to farming.


Image via Pixabay.

A collaborative effort between archaeologists, geneticists, and museum curators is helping us piece together what life in sub-Saharan Africa was like thousands of years ago. The study reveals how herding and farming first took root in the region and offers new insight into how groups of humans developed lactose persistence — the ability to digest milk.

Got milk?

“The origins of food producers in East Africa have remained elusive because of gaps in the archaeological record,” said co-first author Mary Prendergast, Ph.D., Professor of Anthropology and chair of humanities at Saint Louis University’s campus in Madrid, Spain.

“This study uses DNA to answer previously unresolvable questions about how people were moving and interacting.”

The study involved experts in several fields from North American, European, and African institutions. The team analyzed ancient samples of DNA retrieved from 41 human skeletons curated in the National Museums of Kenya and Tanzania and the Livingstone Museum in Zambia. From these bits of DNA, the team wanted to piece together the history of early African food producers.

The first food-producing endeavor that spread through most of Africa was the herding of animals — cattle, sheep, and goats. It continues to be a linchpin of local food production throughout the arid grasslands that cover much of sub-Saharan Africa today, feeding millions of people. Previous research has also shown that the Great Rift Valley of Kenya and Tanzania was a key site in the transition from foraging to herding.

Livestock herders first appeared in northern Kenya around 5000 years ago — where they built monumental cemeteries — later spreading south into the Rift Valley. Who these people were and where they came from, however, remained a mystery.

The present study shows that some of the people who carried this knowledge south draw their roots from northeast Africa. These communities later developed in East Africa by mixing with local foragers there between 4500-3500 years ago. This suggests that previous hypotheses holding that animal domestication spread through trade rather than the movement of people were wrong.

“Today, East Africa is one of the most genetically, linguistically, and culturally diverse places in the world,” explains Elizabeth Sawchuk, Ph.D., a bioarchaeologist at Stony Brook University and co-first author of the study. “Our findings trace the roots of this mosaic back several millennia. Distinct peoples have coexisted in the Rift Valley for a very long time.”

These herders and foragers then evolved into genetically-isolated populations in East Africa, though the team says the two groups continued to live side-by-side. There seem to have been strong social barriers between the two groups which persisted long after they met, the team reports.

The next major genetic shift takes place during the Iron Age, around 1200 years ago. This time saw the movement of other groups of people from northeastern and western Africa into the region. Many East Africans today show a heavy genetic legacy from these new groups, the researchers add. The same period also saw the introduction of two new, and massively-important, practices into the area: farming and iron-working.

One important finding of the study is that it shows how East Africa served as an independent center of evolution for lactase persistence, or people retaining the ability to digest milk into adulthood. This isn’t a feature humanity’s ‘factory settings’ include, rather, it’s a genetic adaptation that several groups of people today have inherited from our livestock-herding ancestors. It is found in high proportions among Kenyan and Tanzanian herders today, the team writes, suggesting that this group acquired lactase persistence independently during their history.

The paper “Ancient DNA reveals a multistep spread of the first herders into sub-Saharan Africa” has been published in the journal Science.

Mothers’ breast milk protects children against infection for their entire lives

Mothers’ breast milk may be dramatically more important to the health of infants than previously thought. In a new study, doctors found that momma mice who breastfed their pups transferred immune cells that offered protection against infections long after breastfeeding stopped.

Credit: Pixabay.

Doctors were aware that breastfeeding raises the immunity of an infant, but the assumption has always been that this protection is only temporary, lasting just for the time that infants are breastfed. What’s more, it was always thought that this immunity was due to antibodies transferred from the mother to neutralize bacteria and viruses.

These assumptions have been now been toppled by a new study published today in the journal Science Advances. Researchers at the University of Birmingham in the UK studied rodent offspring nursed by mothers who had a preconception helminth infection. Unexpectedly, the research team found that the protection against the worm infection was passed onto the infants by cells in the milk rather than through proteins such as antibodies. Most striking of all, these transferred cells offered protection throughout the body well into adulthood.

“This is the first demonstration that infection prior to pregnancy can transfer life-long cellular immunity to infants,” said Dr. William Horsnell, lead author of the study and a researcher at the University of Birmingham’s Institute of Microbiology.

“The work shows that exposure to an infection before pregnancy can lead to a mother transferring long term immune benefits to her offspring. This is remarkable and adds a new dimension to our understanding of how a mother can influence our health.”

In the future, the researchers would like to use this newfound knowledge to create vaccines that prevent infections. The reasoning is simple: if the immune system of mothers and would-be-mothers is primed against infectious diseases through vaccination, then babies could reap the same protective effects through breastfeeding. This new study suggests that this protection could be permanent, which is simply remarkable.

“We hope this research will lead to human investigations into how maternal exposure to pathogens prior to pregnancy can influence infant health,” added Professor Kai-Michael Toellner, of the University of Birmingham’s Institute of Immunology and Immunotherapy.

Baby jumping spiders sucking milk from their mother's birth cannal. Credit: Rui-Chang Quan.

Spider milk is a thing, and it’s 4 times more nutritious than cow’s milk

Baby jumping spiders sucking milk from their mother's birth cannal. Credit: Rui-Chang Quan.

Baby jumping spiders sucking milk from their mother’s birth canal. Credit: Rui-Chang Quan.

One summer evening, Chinese researchers were minding their own business in their lab in Yunnan, China, when they came across a peculiar sight. Inside a nest, they saw a juvenile jumping spider attached to its mother like a baby mammal sucking milk from a mamma’s teat. Strikingly, investigations showed that the young spiders really were sucking milk — spider milk! It’s the first time that milk production has been reported in arachnids or any invertebrate, for that matter. It’s very nutritious, too. Researchers reported that the jumping spider’s milk contains 4 times the protein, fat, and sugar typically found in cow’s milk.

The one-of-a-kind findings could help researchers piece together the evolutionary origins of very complex parental care, such as mammalian nursing. Given that we’re talking about a jumping spider (Toxeus magnus), a long-standing hypothesis that prolonged mothering requires complex brain power could be turned on its head.

What’s remarkable is not only the fact that a spider can produce milk but also how long it provides it to its young. Once the female spider’s eggs hatch, the mother deposits milky droplets around the nest, which the babies sip gladly for a couple of days. After the droplets are exhausted, the young spiders line up at the mother’s birth canal to suckle more milk. At the ripe old age of 20 days, the young start to hunt outside the nest, but they will still consume their mother’s milk until they become sexually mature, another 20 days later. Other spider species may hang around their young a couple of days after they hatch, but they never feed them.

When the researchers cut off the juveniles’ milk supply by painting the mother’s birth canal, all spiders younger than 20 days died. When the mother was removed from the nest, older spiders that were still being nursed grew slower, left the nest sooner, and were more likely to die before reaching adulthood, as reported in the journal Science.

The milk-like secretion could actually be liquefied eggs, wrote the authors of the new study, who work at the Chinese Academy of Sciences’ Center for Integrative Conservation in Menglunzhen. Previously, researchers have described other non-mammals producing milk-like substances, such as pigeons or cockroaches. However, a cockroach’s milk-like secretion is absorbed passively through the eggshell of the embryos and is not part of the hatchlings’ diet.

Extended maternal care was thought to be a behavior evolved by only a couple of long-lived social vertebrates, such as humans or elephants. However, the new study shows that invertebrates have also evolved this ability.  The study’s authors do not explain why the spiders nurse their young for so long or why other species of spiders do not produce milk. Nevertheless, the findings provide a reminder that spiders aren’t necessarily cold and harsh creatures.

The Pacific beetle cockroach. Credit: Yasu Ueda/Flickr.

Cockroach milk might become the next superfood on millenials’ wish list

Move over almond milk and avocado, there’s a new superfood in town: cockroach milk. Wait a second — don’t roll your eyes just yet, because this is actually a serious possibility which researchers and some companies are investigating. Apparently, cockroach ‘milk’, or rather the liquid postnatal secretion of a certain cockroach species, is one of the most nutritious substances that we know of. Pound for pound, cockroach milk reportedly contains three times the energy of an equivalent mass of dairy milk.

The Pacific beetle cockroach. Credit: Yasu Ueda/Flickr.

The Pacific beetle cockroach. Credit: Yasu Ueda/Flickr.

The first hints that cockroach milk is worth our attention came in 2016, when an international team of researchers reported the first study of protein crystals sourced from the Pacific beetle cockroach (Diploptera punctata). This is a unique cockroach, in the sense that its the only viviparous roach that scientists know of. Like humans, the young are directly nourished inside the womb by the mother before they are born. So, while its relatives lay eggs, the Pacific beetle cockroach gives birth to live young.

Of course, that doesn’t mean that this cockroach has nipples. That would be odd. Instead, the milk is obtained by opening an embryonic beetle roach, whose guts will spill out nutrient-rich milk crystals that shimmer like glitter.

Diploptera punctata is the only known viviparous cockroach, an evolutionarily advanced condition in which the eggs have little yolk, but the developing offspring are nourished directly by the mother from the brood sac wall. Viviparity enhances larval development, because the time to reproductive maturity is substantially reduced in D. punctata relative to ovoviviparous species,” wrote the researchers in their study.

Nevertheless, the liquid secretion, which we’ll just call milk for the sake of simplification, is super nutritious, being rich in proteins, fats, and sugars. An analysis of the protein sequences showed that they have all the essential amino acids.

Since the study was first published, some people have taken note and are currently experimenting with ways to turn cockroach milk into food for human consumption. Gourmet Grub, a South African ice cream company, is one of the important companies giving cockroach milk serious consideration. Their solution is called “entomilk”, which is sourced from sustainably farmed insects. Gourmet Grub claims that it may be possible to harvest entomilk in a far more environmentally friendly manner than the traditional farming of dairy cows.

There are a couple of hurdles before this can happen. Firstly, scientists need to prove that cockroach milk is safe for human consumption, something which studies in the future will address. Secondly, milking cockroaches is tough work. Ten cockroaches produce only half a milliliter of product, and the harvesting process itself isn’t easy. As such, this might end up being a pretty expensive product, although even a sprinkle of cockroach milk in protein drinks could still be good. Some researchers are currently experimenting with genetically modified yeast — which is far easier to grow and harvest — to produce the same milk as beetle roaches.

But at the end of the day, the biggest obstacle in the face of widespread cockroach milk adoption is convincing people that it’s not a gross thing (provided scientists prove it’s safe). The taste itself isn’t anything special, confided Subramanian Ramaswamy, one of the researchers, to the Washington Post

So, any takers? Anyone?

Milk Bottles.

What is pasteurization, and how does it keep milk fresh for 9 months at a time?

Milk Bottles.

Image credits Pasita Wanseng.

Modern agriculture has a lot of perks. Today, food is plentiful on a scale humans in pre-industrial societies could barely dream of (although we’re still pretty bad at getting it to those who need it the most), consumers have a huge range of options and enjoy very high food security.

But it also comes with its drawbacks — among them, longer distances between farms and consumers. With it came the need to process foodstuffs so they don’t spoil, rot and generally become undesirable by the time they reach our tables. We’ve toyed around with a host of such methods throughout history, and their success (or failure) have shaped whole cultures.

There are simply too many to fit into a single article. So for starters, we’ll talk about one of the most commercially-important methods of preservation in modern industries. A technique that turned milk and dairy from one of the most dangerous and deadly class of foodstuffs in the world to something you can keep fresh and safe for almost a whole year. Today, we’ll be answering the question of:

What is pasteurization

In short, pasteurization is a process that relies on heat treatment of foodstuffs to kill bacteria, viruses, and other pathogens in foodstuffs. The process was established by Louis Pasteur, a French chemist who tried to enjoy his 1864 vacation in the Arbois region but find it impossible to do so — because local wines were often excessively sour. Armed with his scientific prowess and a Frenchman’s burning love for wine, Louis would spend that holiday developing a method to keep young wines from spoiling.

Kermit with wine.

Louis Pasteur, on vacation in 1864, faced with the prospect of yet another bottle of sour wine. Probably.
Image credits Alexa_Fotos / Pixabay.

His work showed that heating the drink even under the boiling point of water (50–60 °C / 122–140 °F) would kill off most germs that caused spoilage (and thus keep the wines from souring) while maintaining flavor and aroma. Still, the process remained in use only for wine and beer, and would be applied to other foodstuffs, such as milk, many years after its development. For example, milk in 1870’s US was routinely laced with substances to mask spoilage, and pasteurization was taken up only after the government stepped in to regulate what could and couldn’t end up in milk.

However, it’s important to note that pasteurization doesn’t sterilize (kill all the germs in) foodstuffs, but just culls their numbers enough to make them unlikely to cause spoilage or disease in humans — assuming the product is stored as indicated and is consumed before its expiration date. Sterilization of food isn’t commonly seen because it often affects the taste and quality of the food.

How it came about

The closest process to what we know as “pasteurization” today is, surprisingly enough, the oldest on the list. The Chinese seem to have developed a heat-treatment method to keep wine from spoiling as early as 1117 AD, and it later found its way to Japan, where a Buddist monk describes it in 1568 in his diary, known today as Tamonin-nikki. These methods sound, in principle, very much like modern pasteurization, only they were in use hundreds of years before Pasteur’s vacation.

Although deprived of ancestral Chinese brewing knowledge, Louis didn’t have to start from scratch. It’s likely that he based his works on a previous food preservation method known as appertisation — or as “canning.”

Jam jars.

Deliciously effective.
Image credits Lebensmittelfotos.

This process is named after French cook, brewer, and confectioner Nicolas Appert. In the height of the Napoleonic Wars, the French government needed to ensure that its soldiers were well fed on very distant fronts — so they needed a new way to keep food from spoiling. To this end, they offered a 12,000 francs reward to any who could solve their problem, and Appret was just the man to do it. He had been experimenting with placing food in glass jars sealed with cork and wax, then dumping them in boiling water.

Just like pasteurization, appertisation uses heat-treatment to kill off any flora that could cause food to spoil, and the sealed container prevents any new germs from moving back in. But unlike pasteurization, appertisation uses high temperatures so the food is also processed/cooked, and as such, changes the appearance and taste of foods treated this way. But, after several autumns’ experience of helping my grandma stock up on jars of food for winter using appertisation, I can attest that the results are very tasty — just not very useful for wine.

Today, appertisation is used mostly for canning. And although Appert used it to preserve milk, appertisation just isn’t very good for that — too much heat and casein, a protein in milk, will make the liquid curdle into cheese. So unless you want to make cheese (we totally have a tutorial on that by the way,) appertisation isn’t the way to go. Pasteurization, however, works great for milk, alcoholic beverages, juices, and a whole range of items you need to be preserved but not over-done.

To find out why, let’s take a look at how it’s done.

How pasteurization happens

To start off, I need to point out that for something to be officially “pasteurized” it has to follow some very strict standards (set by national food agencies so they can vary a bit from place to place) — for example, in Canada milk intended for consumption has to be heated to 72 °C (162 °F) for at least 1 second, while in the UK it has to be treated at 71.7 °C (161 °F) for 15 seconds. These standards also differ from product to product: you can’t use the same technique to pasteurize milk or whole cream, for example.

Past your eyes.

Couldn’t resist.
Image via Imgur.

As I’ve said, pasteurization aims to preserve food without cooking/boiling it. In the past, this was mainly done by simply not heating the food in question past the temperature you wanted. That, however, has the drawback that it makes the process much longer. More recent methods rely on much higher temperature (even above boiling point) but much shorter treatment periods to avoid ”cooking” the items. The most used types of pasteurization used today are high-temperature, short-time (HTST or “flash pasteurisation”), ultra-heat-treated (UHT), and extended shelf life (ESL)

HTST treatment is performed by running milk either over heated metal plates or through heated metal pipes, where it’s kept at 72 °C (161 °F) for 15 seconds. It’s a pretty intermediate approach, using moderate intensity heat applied for a moderate amount of time. This is your run of the mill pasteurization method and lends itself well to pretty much anything. When you see a carton of milk labeled simply as “pasteurized,” you’re usually seeing HTST-treated milk.

Ultra-heat-treatment on the other hand subjects the milk to temperatures of around 140 °C (284 °F), but only for four seconds. The process involves spraying the milk through a nozzle in into high-temperature, pressurized steam. After it reaches that maximum temperature, the milk is rapidly cooled down in a vacuum chamber and packaged in an airtight, sterile container. UHT is a very deadly process for bacteria, and the resulting product is actually sterilized not just pasteurized. As a result, UHT products like milk and juice in the right packing can safely be stored even without refrigeration for up to 9 months at a time. Products treated this way are generally labeled as “UHT” or “ultra-pasteurized”, although this can vary from place to place.

Finally, extended shelf life milk uses lower temperatures that UHT but mixes in a microbial filtration step to the process. European countries (with the exception of Germany) don’t require manufacturers to label ESL milk as being ultra-heated, so you can often find it labeled as “fresh”. Still, ESL and traditionally pasteurized milk are processed differently and have different properties — especially important when you’ll start making your own cheese.

Does it work?

Oh, boy does it. Before pasteurization, milk that didn’t come fresh out of the udder was probably one of the most dangerous foodstuffs available as it’s an awesome environment for germs. To put things into perspective, some 65,000 people died of tuberculosis contracted from days-old milk in England and Wales alone between 1912 and 1937, before pasteurization became widely-used. And it wasn’t just tuberculosis — you risked brucellosis, diphtheria, scarlet fever, Q-fever, and a host of other nasty bacteria with every sip of milk you drank. Even today, improperly processed raw milk causes nearly three times more hospitalizations than any other food out there, the CDC says.

But a 15-seconds pasteurization process will leave only one in a million to ten million germs alive (between 6.7 and 6.9 mean log10 reductions) — meaning a glass of pasteurized milk is probably one of the safest food items we can enjoy. A simple process that makes a world of difference.

So if you happen to produce a lot of milk at home, make sure to pasteurize it, just to stay on the safe side. FDA guidelines allow for home pasteurization at 63 °C (145 °F) for 30 minutes.

Tasmanian devil

Tasmanian devil milk might be the secret weapon against superbugs we’ve been waiting for

Tasmanian devil

Credit: Pixabay

Leading medical societies have warned time and time again that antibiotic resistance is looming and the effects could prove catastrophic. While some are working on synthesizing new classes of antibiotics in the lab, other groups are focusing on finding them in nature. After more than three years of research, Australian researchers think they found one of the most promising compounds against superbugs in the milk of an adorable, yet highly aggressive marsupial: the Tasmanian devil.

Momma’s milk

The discovery was made by a team at Sydney University who sequenced the devil’s genome. Devil mothers only need 21 days to gestate a pup, after which development continues in the pouch, as is the case with most marsupials. Given the short gestation and knowing a pouch is far from being the most sterile environment, the researchers presumed that the devil momma’s milk has to offer strong antimicrobial resistance.

Eventually, they found devil milk contains six varieties of peptides belonging to a class called cathelicidins, which act as natural antibiotics. Humans only have one, but most marsupials seem to have them in great abundance. Opossums have twelve and the tammar wallaby carries eight.

The peptides were replicated artificially then tested against a variety of germs, some of whom the most dangerous known to humans. The peptides proved effective against everything the researchers put out. Among the germs was Staphylococcus aureus, a bacteria that’s found in the nose and skin of 30 percent of people. While it’s harmless most of the time, the bacteria can prove fatal if it reaches the blood stream.

Another bacteria was enterococcus, which some strains are already resistant to vancomycin, one of the strongest antibiotics in our arsenal.

Emma Peel with a young Tasmanian devil.  Photo: Emma Peel

Emma Peel with a young Tasmanian devil. Photo: Emma Peel

Last year, an 18-month review into antimicrobial resistance found superbugs might kill 10 million people a year by 2050 or more than cancer.

“There are potential pathogens present in the devil microbiome, so the fact that the under-developed young in the pouch don’t get sick was a clue something interesting was going on,” said Emma Peel, one of the authors of the study published in Scientific Reports. “That’s what inspired our most recent study.”

It’s remarkable that a creature that’s on the brink of extinction might one day save millions of human lives. In only ten years, 80 percent of Tasmanian devil populations have collapsed at the hand of a nasty transmissible face cancer with an almost 100 percent fatality rate. Luckily, some individuals have developed resistance and it seems like the devils will survive. 

Next, the researchers plan on studying koalas as preliminary results suggest their milk also contains similar peptides.

Cockroach milk: superfood of the future?

It might sound gross, but cockroach milk might be making its way into some diets as a superfood. A team of researchers has just sequenced a protein crystal from the midgut of cockroaches that they believe is more than four times as nutritious as cow’s milk.

The Diploptera punctata cockroaches that produce that unique milk. Credit: University of Toronto

The Diploptera punctata cockroaches that produce the unique milk. Credit: University of Toronto

There’s only one species of cockroach that’s known to give birth to live offspring and produce a type of “milk” that contains protein crystals to feed its babies – Diploptera punctata. Further examination of these crystals revealed that just one of them contains over three times the amount of energy found in the same amount of buffalo milk, which contains more energy than standard dairy milk.

In the current study, the team sequenced the genes responsible for producing these unique cockroach milk crystals and replicated them in the lab. Successful replication of these milk crystals opens up the possibility of introducing these proteins into our diet in the future, since milking a cockroach isn’t exactly a realistic option.

“The crystals are like a complete food – they have proteins, fats and sugars,” said Sanchari Banerjee, first author of the study. “If you look into the protein sequences, they have all the essential amino acids.”

In addition calorie and nutrient levels that give them superfood status, they are also time-released, meaning that the crystals release more proteins at a steady rate as they are digested.

“It’s time-released food,” said Subramanian Ramaswamy, senior author of the study. “If you need food that is calorifically high, that is time released and food that is complete. This is it.”

Despite all of its benefits, it’s unlikely that cockroach milk will make its way into many western diets since they already continue too many calories. However, the milk is ideal for those looking for a simple way to get all of the calories and nutrients that they need and it wouldn’t be surprising if they make their way into protein supplements.

“They’re very stable,” Ramaswamy said. “They can be a fantastic protein supplement.”

Journal Reference: Structure of a heterogeneous, glycosylated, lipid-bound, in vivo-grown protein crystal at atomic resolution from the viviparous cockroach Diploptera punctate. 27 June 2016. 10.1107/S2052252516008903

Foamy gold is mostly empty, floats on coffee

Imagine a nugget of real, 20 carat gold floating merrily on the milk foam of your cup of warm cappuccino — scientists from ETH Zurich have found a way to do it. It’s not super-cappuccino, or diamond-strong foam — scientists led by Raffaele Mezzenga, Professor of Food and Soft Materials at ETH have produced a novel foam of gold, a three-dimensional material that is actually mostly…empty.

This 20 carats gold foam is lighter than milk foam.
Image via ethz

“The so-called aerogel is a thousand times lighter than conventional gold alloys. It is lighter than water and almost as light as air,” says Mezzenga.

To the naked eye it looks just like a sturdy, shiny block of conventional gold, but that’s where the resemblance ends — this foamy gold (that’s what I’m calling it) is soft and malleable by hand. It’s 98 percent air held together loosely by gold (four-fifths of the solid material) and milk protein fibrils (one-fifth), qualifying it as 20 carat gold.

The material is created by first heating milk proteins until they coalesce into nanometre-fine fibres named amyloid fibrils. The fibrils are placed in a solution of gold salt, where they interlace into a basic structure that the gold crystallizes on in small particles. The end result is a gel-like gold fibre network.

“One of the big challenges was how to dry this fine network without destroying it,” explains Gustav Nyström, postdoc in Mezzenga’s group and first author of the study.

Air drying wasn’t viable as it could damage the gold structure, so the scientists opted for a gentler but more laborious process that relies on carbon dioxide, assisted by the Professor of Process Engineering Marco Mazzotti.

This method of production, where the metal particles crystallize during the manufacture of the protein scaffold rather than after its completion, is novel. And one of its biggest advantages is that it makes it easy to create a homogeneous gold aerogel that mimics gold alloys perfectly.

It also allows scientists numerous possibilities to influence the properties of the material.

“The optical properties of gold depend strongly on the size and shape of the gold particles,” says Nyström. “Therefore we can even change the colour of the material. When we change the reaction conditions in order that the gold doesn’t crystallise into microparticles but rather smaller nanoparticles, it results in a dark-red gold.”

A foam of amyloid protein filaments without gold (top), with gold microparticles (middle) and gold nanoparticles (below).
Image via ethz

The new material could be used in many of the applications where gold is currently being used, says Mezzenga. The substance’s properties, including its lighter weight, smaller material requirement and porous structure, have their advantages. Applications in watches and jewellery are only one possibility.

Another use demonstrated by the scientists is chemical catalysis: since the highly porous material has a huge surface, chemical reactions that depend on the presence of gold can be run in a very efficient manner. The material could also be used in applications where light is absorbed or reflected. Finally, the scientists have also shown how it becomes possible to manufacture pressure sensors with it.

“At normal atmospheric pressure the individual gold particles in the material do not touch, and the gold aerogel does not conduct electricity,” explains Mezzenga. “But when the pressure is increased, the material gets compressed and the particles begin to touch, making the material conductive.”

Is Dairy Addiction Real? Here’s what science says

Dairy Addiction is one idea toted not only as a notion, but as a fact by a significant number of vegans, especially ones that do not link to any reliable source (if any at all) to provide any evidence to the conclusion they have reached. So I decided that I will take it upon myself to find out whether or not the scientific literature agrees with this.

First things first though, WHY do these people believe that Dairy products are addictive? Well, YUM Universe, a known vegetarian blog, sums it up like this:

The answer is casomorphins—protein fragments, derived from the digestion of the milk protein, Casein. The distinguishing characteristic of casomorphins is that they have an opioid effect. ”

Casomorphins, or in the case of milk, Beta-Casomorphins, are indeed a form of opioid found in milk. And yes, Opioids are addictive, so that must mean milk is addictive and we can just close this case, right? Well… not quite.

One study of milks effects on rats published in 1981 called Opioid Effects of Beta-Casomorphines mentioned that they found “none of the peptides displayed opioid activity.” This is not the only study either, as another study published in 1994 which focused entirely on this idea of the addictive qualities of milk named “An Assessment of the Addiction Potential of the Opioid Associated with Milk” concluded with the line “Ingestion of milk products containing β-casomorphin is not likely to become the focus of an addiction.”

This is not even the last of it, as there is even a case report of a woman in Germany who drank 4-5 liters of milk a day. The report wanted to know if the woman’s consumption of such high quantities of milk was pathological. It concluded that based on the fact that the woman did not have any withdrawal symptoms in the absence of milk that Milk drinking in this patient did not have the characteristic physiological, behavioral and cognitive phenomena associated with dependence and nondependence producing substances.”

Opioid containing foods go far beyond casomorphins as well, as there is Gluten Exorphin in wheat, Soymorphin in soy, and even Rubiscolin found in spinach. I see no argument that spinach and tofu is addictive by anybodies standards ever.

Now am I saying that dairy products are NOT addictive? Of course not, they certainly are in a sense, but this is not due to casomorphins. Milk is a high fat food, and as any nutritionist knows, foods high in fat, sugar, and salt can be addictive the same way drugs are. This was actually a survival mechanism in the past, as since food scarcity was an issue, it was better to consume foods that were higher in essential nutrients needed for our survival, such as fatty, sweet, and salty foods.

But this is not a milk-only issue. You can easily state this for any other high-fat, sweet, or salty foods, including avocados, fried lettuce, mangoes, nuts, juices, vinegar, and anything you add salt to. Literally ANY food that is sweet, fatty, or salty has the potential to be addicting, which is why these three food types are such an issue to anybody suffering from Binge Eating Disorder, otherwise known as a Food Addiction.

Tons of food can be addictive, but I can safely say that casomorphin, or food opioids at all, do not play any role in that.

Cheese has a 7500 year history

Polish researchers have found the earliest evidence of prehistoric cheese-making from a study of 7,500-year-old pottery fragments that are perforated much like today’s modern cheese strainers.

When early men figured out how to make cheese, it was a big thing; at that time, livestock was too precious to use just for the meat, and mankind was largely lactose intolerant, making cheese the perfect culinary alternative. The introduction of dairying turned out to be a critical step in early agriculture, with products being rapidly adopted as a major component of the diet.

Researchers from the University of Bristol in Britain, with colleagues in the United States and Poland analyzed fatty acids embedded on prehistoric pottery from the Polish region of Kuyavia, and they found the pottery was used to separate milk into fat-rich curds for cheese and lactose-containing whey. Whey (or milk serum) is the liquid remaining after milk has been curdled and strained – a byproduct of cheese manufacturing.

“The presence of milk residues in sieves … constitutes the earliest direct evidence for cheese-making,” said Mélanie Salque from Bristol, one of the authors of the research, which was published in the journal Nature. Peter Bogucki, another researcher involved in the work, said: “Making cheese allowed them to reduce the lactose content of milk, and we know that, at that time, most of the humans were not tolerant to lactose.”

Cheesemaking today

Traces of milk have been found in 8.000 year old sites in Turkey and Libya, but with no real indication that the milk was turned into cheese.

“It is truly remarkable, the depth of insights into ancient human diet and food processing technologies these ancient fats preserved in archaeological ceramics are now providing us with,” said Richard Evershed, who heads the Bristol team.

Shorties: US is the only developed nation to drink milk from cows given artificial hormones

As an European, it often seems to me like the US is a land of striking contrasts – it is in fact the land of opportunities. Matter of fact, I was absolutely shocked to find out that the US is still allowing milk from cows which were given artificial growth hormone, especially since this hormone was banned in Canada, Australia, New Zealand, Japan and all European Union countries by 2000 or earlier.

Bovine somatotropin (abbreviated bST and BST), or BGH is the chain of aminoacids produced by the cow’s pituitary gland which is responsible for growth. The effects on the human body are, although not fully documented, obviously harmful. It is known that it can lead to several types of cancer (especially breast cancer) and the nutritional level also goes down.

Even though all the civilized world banned it, in the US it is sold in all the 50 States.