Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


New conservation methods increase risk of food poisoning

In response to consumer demand for more natural food, the food industry has reduced the amount of preservatives in food over recent years. A common preservative is acetic acid, which is used to stop bacterial growth in dressings, sauces, cheese and pickles. However, new research shows that a small amount of acetic acid does not have the intended effect, but rather the opposite – it increases the amount of toxin from the harmful bacteria in the food.

“In my studies I saw that a small amount of acetic acid caused the bacteria to become stressed, which meant they reacted by producing more toxin. However, if a large amount of acetic acid is added, as was done in the past, the acidity is greatly increased and the bacteria do not survive”, explains Nina Wallin Carlquist, Doctor of Philosophy in Engineering at the Division of Applied Microbiology, Lund University.

She recently defended a thesis on the subject, in which she studied two of the most common food poisoning bacteria, Staphylococcus aureus and Campylobacter jejuni.

The Staphylococcus were used in the acetic acid study. A common vehicle for staphylococcal food poisoning is pork meat. Therefore Nina Wallin Carlquist also chose to study how these bacteria behave in different types of pork meat at room temperature: boiled and smoked ham, Serrano ham and salami. The bacteria could get into the food in the first place from an infected cut on the finger of the person who has handled the meat, for example.

Her results show that it only took a few hours for the bacteria to multiply in the boiled and smoked ham. In the Serrano ham, it took a week before the number of bacteria increased and on the salami they did not survive at all.

“A possible explanation is that the bacteria could not survive the salami’s combination of acidity, salt, fat and dryness. However, there are other bacteria that thrive on salami. The Serrano ham is manufactured and stored at room temperature over long periods, which means it is important that the staff have good hygiene so that the Staphylococcus cannot get a foothold”, comments Nina Wallin Carlquist.

A starting point was to study how the bacteria behave in food. This type of research is otherwise usually carried out in a controlled environment in laboratories where a pure culture of a certain type of bacteria is studied. According to Nina Wallin Carlquist this provides far from the whole picture because the bacteria are affected by other micro-organisms in the food and also by how much fat, acid and salt the food contains.

“If we know more about what it is in the food that enables the bacteria to thrive, we can then adapt the composition of the food product and thereby improve food safety. This is a new way to approach food safety”, explains Nina Wallin Carlquist.

The other bacterium, Campylobacter jejuni, is becoming the next big problem after salmonella. Like salmonella, the bacteria occur naturally in chicken, without harming the host animal. However, if the contents of the intestines come into contact with the meat during slaughter, the meat can become infected. If the chicken is then not properly cooked the consumer may suffer food poisoning.

“It would be best if the chickens did not get infected with these bacteria to begin with. In my studies I have therefore found out how the bacteria become established in the intestines. In the long term, these results could help in the drawing up of guidelines for hygiene procedures on poultry farms or in developing a vaccine for the animals”, says Nina Wallin Carlquist.

Nina Wallin Carlquist, Doctor of Philosophy in Engineering at Applied Microbiology, tel.: +46 (0)70 67 66 873, or

Supervisor Peter Rådström, Professor at the Division of Applied Microbiology, +46 (0)46 222 34 12,

Pressofficer Kristina Lindgärde;; +46-709 753 500

Kristina Lindgärde | idw
Further information:

More articles from Health and Medicine:

nachricht Advanced analysis of brain structure shape may track progression to Alzheimer's disease
26.10.2016 | Massachusetts General Hospital

nachricht Indian roadside refuse fires produce toxic rainbow
26.10.2016 | Duke University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

How nanoscience will improve our health and lives in the coming years

27.10.2016 | Materials Sciences

OU-led team discovers rare, newborn tri-star system using ALMA

27.10.2016 | Physics and Astronomy

'Neighbor maps' reveal the genome's 3-D shape

27.10.2016 | Life Sciences

More VideoLinks >>>