Posted on 02/16/2022 7:29:04 AM PST by Red Badger
Vietnamese fermented pork snack, Nem Chua. Credit: RMIT University
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Fermented meat snack is helping researchers develop a safe, all-natural food preservative.
A traditional Vietnamese meat snack could hold the key to developing a safe and natural food preservative, addressing the twin global problems of food waste and food-borne illnesses.
Bacteria-killing compound discovered in Nem Chua, a fermented pork snack
Toxic to bacteria but safe for humans, it’s a natural alternative to artificial food preservatives
Study reveals ideal growth conditions to potentially make the bacteria-killer at industrial scales
The fermented pork snack, Nem Chua, is eaten raw but does not cause food poisoning when prepared correctly.
This is because friendly bacteria that thrive in the fermented meat make a special compound that destroys more dangerous bacteria.
Now researchers at RMIT University in Melbourne, Australia, have shown how this natural bacteria-killing compound could be used to keep food fresh for longer.
Food waste is a global issue that costs around $US680 billion annually in industrialized countries, consumes nearly a quarter of the water used in agriculture, and produces 8% of global greenhouse emissions.
Food-borne diseases like Listeria or Salmonella affect millions each year and can be life-threatening for pregnant women, older people, and those who are immunocompromised.
Listeria Bacteria
Listeria bacteria (green) dying after exposure to Plantacyclin B21AG. The bumps visible on many of the cells are the cell contents beginning to leak out. Credit: Dr. Elvina Parlindungan
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Co-lead researcher Professor Oliver Jones said changes in consumer habits have led to a greater demand for natural alternatives to artificial food preservatives.
“Scientists have known about these bacteria-killing compounds for many years but the challenge is to produce them in large enough quantities to be used by the food industry,” said Jones, Associate Dean of Biosciences and Food Technology at RMIT.
“The Nem Chua compound is colorless, odorless, tasteless, and very resilient.
“Through this new research, we’ve identified the right growth conditions that would enable us to make it in large amounts, potentially at industrial scales.
“With further development, we hope this could be an effective, safe, and all-natural solution for both food waste and food-borne disease.”
Bacteria-killing weapon
A team of RMIT researchers was inspired to investigate Nem Chua for its potential antibacterial properties after traveling to Vietnam and observing people eating the raw meat snack without getting sick, despite the hot and humid climate.
The team, led by Professor Andrew Smith (now at Griffith University) and Dr. Bee May, discovered a new type of bacteria-killing compound in Nem Chua.
Plantacyclin B21AG is one of a group of compounds known as bacteriocins, which are produced by bacteria to destroy rival bacterial strains.
Listeria Plantacyclin B21AG
Left: Listeria bacteria, alive and with intact cell membranes. Right: The same bacteria after exposure to Plantacyclin B21AG, dead and with the cell membranes destroyed. Credit: Dr. Elvina Parlindungan
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Bacteriocins form holes in the membranes of target bacteria. This causes the contents of the cell to leak out — effectively killing the bacteria.
The problem is most bacteriocins only work against one or two types of bacteria and they are not very stable in different environmental conditions.
Only one — Nisin, which came to market in the 1960s — is currently licensed for use as a food preservative, in a market estimated to be worth more than $US513 million in 2020, but this compound is temperature and pH sensitive limiting its use.
Tough and effective
The Nem Chua-derived compound is more robust than Nisin and is effective against a wide range of bacteria even after exposure to a range of environments typical in food processing.
It can survive being heated to 90C for 20 minutes and remains stable across high and low pH levels.
The compound can also destroy a range of disease-causing organisms commonly found in food including potentially life-threatening Listeria, which can survive refrigeration and even freezing.
Co-lead researcher Dr. Elvina Parlindungan, who completed the new study as part of her PhD research at RMIT, is now a postdoctoral fellow at APC Microbiome, part of University College Cork in Ireland.
“Using bacteriocins as food preservatives effectively means we are turning bacteria’s own toxic weapons against them — harnessing nature’s smart solutions to tackle our big challenges,” Parlindungan said.
“In the future, these compounds might also be useful as an antibiotic in human medicine.”
Researchers at RMIT’s School of Science have begun experimenting with methods to further purify the compound and are planning to incorporate it into test food products.
Reference:
“Factors that influence growth and bacteriocin production in Lactiplantibacillus plantarum B21″ by Elvina Parlindungan, Chaitali Dekiwadi and Oliver A. H. Jones, 18 May 2021, Process Biochemistry.
DOI: 10.1016/j.procbio.2021.05.009
The team is keen to collaborate with potential industry partners to further develop the technology.
This work was supported by a PhD scholarship from the Indonesian Endowment Fund for Education (LPDP), part of the Ministry of Finance of the Republic of Indonesia, awarded to Parlindungan.
See: Trichinella.
When I was a kid, they used tobacco juice as a cure for ‘worms’....................
when prepared correctly....
Wait until Fauci files for his patent.
It is a sausage.
People have been making them since time began.
Whinybutts have been telling us not to eat them for a century now but since this one comes from the mystic east (oooooo) it is fine.
Whatever.
Copenhagen?
OMG, if this stuff has an odor or taste anything like my Filipina wife’s fermented fish, shrimp paste, etc., I’m running far, far away...
Garrett......................
Reminds me of a Chinese sausage made in USA called kam yen jan.
It is not refrigerated or cooked, but you cook it after opening.
https://www.amazon.com/Kam-Yen-Jan-Chinese-Sausage/dp/B007X6DOG6
I found it for $2 lb at snackathon foods
I could live on Pho tai nam.
Indeed...
They solved the bacteria problem but not the Trichinosis that a parasite in Pork...
Oh well...
True dat.
5.56mm
Speaking of fermented, I found a 1993 bottle of Gallo White Zinfandel cleaning out my parent’s basement a couple of days ago. I fear it has fermented into vinegar.
And no, the bottle of wine was not doing the basement cleaning.
If the cork is intact, it may be fine...................
“Nem Chua is eaten raw, not dry cured.”
I understand, so is citrus cooked fish (Tartare) and it is completely safe. The sausage you make before dry curing into Salami is raw too. The only difference here is the length of time they are cured. Dry Salami is actually still raw just fermented longer. That is why I said “similar”.
https://food-hacks.wonderhowto.com/how-to/cook-fish-without-actually-cooking-0164582/
Actually... That is not the case anymore.
“One of the main reasons for my parents fear of undercooked pork was the nasty little illness called Trichinosis which is caused by the trichinella parasite.
Without going into too much detail and potentially putting you off eating pork for life, let’s just say that if you got sick with trichinosis it was unpleasant.
However, it was long ago established that the practice of feeding pigs ‘Slops’ was a major contributing factor in the parasite being present in the pork, and so the industry got strict about the types of food that could be given to commercially reared pigs.
Since that change in feeding practices, the cases of people contracting trichinosis from undercooked commercially reared pork have been virtually eradicated.
Between 2008 – 2012, there were 10 instances of trichinosis in the USA that were attributed to commercial pork, and only 5 of those were attributed to undercooked pork.”
https://yourmeatguide.com/meduim-rare-cooked-pork-is-safe-to-eat/
No
“Dry Salami is actually still raw just fermented longer.”
Salami is NOT raw.
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