porno izle izleme sitesi porno
Food Chemistry.
Food Microbiology.
Texture Analysis - Measuring That Bite.
Glitterbug - Teaching Correct Hand Washing Technique

What We Do Best

Smarter Tools for Food Safety & Quality

Jan 27, 2009

Arrow Scientific provides the smartest products for food microbiology and HACCP based on the latest technologies; saving time, labour and money.

Arrow offers products in the areas of microbiology, chemistry, pH, temperature, viscosity and texture tests for the lab and on-line testing, vitamin A & D assays, plus software for sensory or statistical process analysis and handwashing training.

We let you target food safety and quality with a wide range of smarter tests and equipment.

More

Subscribe to Arrow News

Smarter Food Technology eNews. Get it Free.
xxx video xnxx

Researchers discover why Listeria bacterium is so hard to fight

The harmful and potentially deadly bacterium Listeria is extremely good at adapting to changes. Now research from University of Southern Denmark uncovers exactly how cunning Listeria is and why it is so hard to fight. The discovery can help develop more efficient ways to combat the bacteria.

 

Listeria is a dreaded bacterium that can be found in both unprocessed and processed foods. Over the last few weeks, 28 persons in Denmark have been infected with Listeria from processed food, sold in supermarkets. 13 have died.

 

The bacterium is notoriously difficult to fight because it has an almost uncanny ability to adapt to changes in its surroundings, says Associate Professor Birgitte Kallipolitis, University of Southern Denmark. Together with colleagues from the Department of Biochemistry and Molecular Biology, she has published a study, which in details reveals how this extreme ability to adapt takes place. 

 

The researchers tested how Listeria reacts when it is exposed to a number of substances that can normally fight pathogenic bacteria. In the laboratory, Listeria was exposed to antibiotics, bile, salt, acid and ethanol, similar to what it often encounters in food, in the human body and during disinfection.

 

Listeria is constantly alert

 

"We knew that Listeria can resist these substances, but we did not quite know how," says Kallipolitis.

 

The researchers discovered that Listeria used a variety of strategies that enabled them to withstand the substances.

 

"Generally speaking, Listeria must be described as extremely adaptable. It is constantly aware of its surroundings and if the environment changes around it. It reacts instantly and has a number of strategies to withstand threats," says Kallipolitis.

 

The researchers also discovered that listeria is an expert at not attracting unwanted attention from the body's immune system.

 

"On the one hand, Listeria needs to produce some special proteins that enable it to infect the cells in our body. On the other hand, it must ensure that the body's immune system does not detect these proteins. It is vital for Listeria to keep a balance between producing enough of these proteins but not so many that they are detected by the immune system—and it masters just that,” explains Kallipolitis.

 

When in the lab, the researchers looked at what happened at the microbiological level. It turned out that Listeria started producing some special RNA molecules, when they were exposed to antibiotics, bile, salt, acid and ethanol.

 

It is all about controlling protein production

 

"With these RNA molecules the bacteria can adjust how much or how little to produce of various proteins. For example it can downgrade the production of the protein LapB, which it uses to enter our cells. If this production is not downgraded, the bacterium will potentially be detected and fought by the immune system,” says Kallipolitis.

 

In other words: Listeria can fine-tune the production of the proteins needed to infect our cells to a point where there is exactly enough to sneak through the immune system’s defense, but not so many that they are discovered.

 

The RNA molecules, produced when Listeria face dangerous environmental changes, also helps Listeria monitor its own cell wall. Antibiotics work by attacking the bacterial cell wall, and when exposed to antibiotics Listeria immediately detects that its cell wall is attacked. This enables it to quickly repair its cell wall—and thus become ready for combat again.

 

"We see this production of RNA molecules only when Listeria is exposed to threatening substances in the lab. When there are no threats, Listeria does not produce them. This reveals part of the mechanism behind Listeria´s extreme adaptability," concludes Kallipolitis.

 

The understanding of how Listeria is able to survive antibiotics, the immune system and disinfecting agents is necessary in order to develop effective means against the life-threatening bacteria.

 

"Only by looking at what the bacteria themselves do to survive, we can become better at fighting their pathogenicity," says Kallipolitis.

 

She and her colleagues are now investigating whether Listeria can be changed into harmless bacteria by removing the RNA molecules.

 

A multicopy sRNA of Listeria monocytogenes regulates expression of the virulence adhesin LapB - http://nar.oxfordjournals.org/content/42/14/9383

 

 

Source: Southern Denmark Univ. - www.sdu.dk/en/Om_SDU/Fakulteterne/Naturvidenskab/Nyheder/2014_27_08_listeria

Ice Cream Chemistry: The Inside Scoop on a Classic Summer Treat

This ACS video breaks down the chemistry of our favourite frozen treat.

By  American Chemical Society    | June 17, 2014

 

www.youtube.com/watch?v=-rlapUkWCSM

 

The summer weather is here, and if you've been out in the sun, you're probably craving some ice cream to cool off. In the American Chemical Society's latest Reactions video, American University Assistant Professor Matt Hartings, Ph.D., breaks down the chemistry of this favorite frozen treat, including what makes ice cream creamy or crunchy, and why it is so sweet.

Romer AgraStrip Gluten G12 receives AOAC Performance Test Certification

Gluten Test Approved

 

Arrow Scientific reports that the Romer Agrastrip® Gluten G12 test strip had recently received AOAC Performance Tested Certification (061403).

 

Arrow Scientific has a complete portfolio for gluten testing from Romer Laboratories, from test strips to test cross-contamination of food contact surfaces or food ingredients and products, to quantitative tests to measure the amount of contamination.

 

Gluten is the main group of proteins in grains such as wheat, rye, barley and to a lesser extent oats consisting of prolamins (in wheat it is gliadin) and glutelins (in wheat it is glutenins). Celiac disease is an immune-mediated gut reaction caused by the ingestion of gluten.

 

Research has found that a short piece of protein called G12 and identified by chemists as a 33-mer peptide from alpha-2 gliadin, is the principal toxic chemical causing gluten intolerance.

 

The G12 tests specifically measure the most immunotoxic proteins for those intolerant to gluten and thereby take analysis in a new direction in assuring food safety.

 

The monoclonal antibody G12 is used to make the ELISA kit called AgraQuant® Gluten G12 for quantitative testing in the laboratory and a lateral flow device (LFD) called AgraStrip® Gluten G12 for onsite factory testing.

 

Real-time testing using on-site lateral flow methods like AgraStrip® Allergen lateral flow tests allow quick testing and immediate decision making, especially when a fast turnaround or trouble shooting is necessary. Everything is supplied within the test kit (no equipment required) and being stored at ambient temperatures allows immediate use of the test. The kits are easy to use, require few skills and only a minimal amount of training.

 

Currently, the list of AgraStrip® Allergen Test Kits includes instant tests for peanuts, gluten G12, hazelnuts, almonds, walnuts, casein, cashews/pistachios, macadamia nuts, brazil nuts, eggs, sesames, mustard and lupins.

 

The implementation of an allergen management system is of great importance for food manufacturers to increase confidence in product safety and reduce the risk of product recalls and the associated brand damage.