Fresh Ideas for Food Safety.
Australia\'s independent research team is developing technologies that may help address concerns about microorganisms that may cause food poisoning and have universal economic value in extending the time for food to remain fresh, this will allow fresh food to be delivered to distant markets.
Many microorganisms that cause food poisoning from fresh vegetables come from human feces (
For example, Chi Heyi)
Or animal sources (
Cryptospores, for example).
Other microorganisms that are potentially dangerous, including B. Wax, Botox, and L. , are naturally present in the soil and rotten plant substances.
Most of the microbial flora on fresh vegetables reflects specific types present during growth and harvesting, although contamination may also occur during storage, transportation and display. L.
In the United States, Liszt has been the cause of public health concern.
Every year, the bacteria cause a high mortality rate from infected diseases, with an estimated 2,500 people hospitalized and 500 deaths.
This bacteria is the main trigger for recalling foods such as hot dogs, luncheon meat, unpasteurized dairy products and softened cheese.
Of the 55 food recalls logged into the United States on 1999, 25 were from L.
Contamination of Liszt with single-cell hyperplasia
Li\'s disease, caused by eating food contaminated with L.
Influenza-producing single-cell hyperplasia of Liszt.
Symptoms such as fever, cold hair and uncomfortable stomach.
If the infection spreads to the nervous system, symptoms such as headache, neck stiffness, confusion or convulsions may occur.
Pregnant women can transmit listeriosis to the fetus through the placenta, with serious or fatal effects. Under U. S.
Policy, if any.
Detection of Liszt in ready-to-
Eating food through standard testing, the manufacturer must remove these items from the market. For fresh-
There is no treatment for cutting raw vegetables that can greatly reduce the number of contaminated microorganisms. Anti-
Separate microbial cleaning is not entirely effective.
The most effective way to reduce risk is to combine control measures, first designed to minimize pollution and limit the growth of microorganisms between farms and slabs, as well as optimized washing procedures.
Cold storage alone does not serve as a deterrent because L.
For example, Liszt, a single-cell hyperplasia, has a good reproduction under cold storage conditions.
So while they may not provide a single, all
Developments in Australia may help provide safer fresh food for consumers.
A collaborative research project at the University of Melbourne and the Australian School of Food Science in the fight against bacteria, a government/academic/Industrial Co-op in Werribee, Victoria, researchers have separated a naturally occurring food preservative, killing L. monocytogenes.
Preservatives are a bacterial substance called piscicolin 126 and are one of many small proteins or peptides produced by lactic acid bacteria.
Lactic acid bacteria have long played a role in food preservation because they are able to produce these proteins that attack bacteria closely related to the production of bacteria.
The milk chain bacteria peptide produced by lactic acid-coseria is the most thorough bacterial substance.
It has been commercially sold since the end of 1950, and many countries have allowed it to be used as a food preservative in canned products, cheese and dairy products. The U. S.
Food and Drug Administration (FDA)
Allowed to be used as an antimicrobial agent in 1988 to inhibit the growth of C.
The formation of botulinum toxin spores and toxins in certain pasteurized cheese products. The zero-
American policy of toleranceS.
The development of a new variant of bacterial element has recently increased the interest of Liszt.
John Coventry, a researcher at the Australian Institute of Food Science, said that nine years ago, he and his colleagues began screening foods with antibacterial properties.
The researchers screened about 700,000 colonies, of which 300 were found to have potentially valuable features.
Five years ago, they discovered and cloned the piscicolin 126, which proved to be a very solid heat. stable peptide.
The research team is now part of the Australian Cooperative Research Center (CRC)
Used in international food manufacturing and packaging science, also known as CRC for food and packaging.
CRC is a cooperative enterprise between companies, government research institutions and universities.
The Piscicolin 126 was produced by the lactic acid bacteria piscicola jg800, which were isolated from the deteriorated ham.
In the preliminary experiment in the medium term
1990 s, applying piscicolin 126 to ham paste, reducing the total number of colonies in L.
Detection of L. Liszt with single-cell hyperplasia below the level (
Less than 100 colonies
Per gram unit)
Use immediately after application.
This level remained unchanged throughout the 14-day test, exceeding the effectiveness of commercial antimatter products and nisin.
Piscicolin 126 was also successfully tested in Camembert cheese and did not inhibit cheese starter bacteria.
This means that the quality of the cheese and the production process will not be affected.
\"Piscicolin 126 has many potential applications, especially in the field of minimum processed foods such as salad products, smoked salmon and fresh food
\"Cut vegetables,\" Coventry said.
\"The real application may be. . .
Spray or coating of food.
In this way, if Liszt enters the surface of the product due to a poor or sub-optimal manufacturing process, then there is an additional control barrier.
\"The site approach is also possible.
Fermented by starter, the milk chain bacteria peptide has been produced in cheese, and the piscicolin 126 may eventually have a similar application model.
However, care needs to be taken to prevent Liszt from producing resistance, for example by using typical care measures to add the bacterial element in an established way so that the protein is not exposed to Liszt in an unplanned manner.
According to Coventry, CRC has reviewed the commercial route of food and packaging, and piscicolin 126 is currently being evaluated by potential business partners.
\"We are out of the discovery and development phase and now any further development work will depend on the business assessment,\" he said . \".
Other experts in food science also believe that piscicolin 126 may be a valuable addition to the food preservation Armory.
\"I think this is a very important step in improving the properties of our food preservatives and limiting the growth of food pathogens,\" said Todd crane hammer . \", William Neil Reynolds, professor of food science and microbiology at North Carolina State University in Raleigh.
\"This development is more important today than it was 20 years ago because we need more preservation barriers to protect our minimum processed and refrigerated foods from things like L. monocytogenes.
Klaammer added, \"some of our emerging pathogens are more suitable for food preservation techniques, and as a result, some food safety measures, such as cold storage, do not work well.
The bacteria added a layer of protection to the food preservation system.
He stressed that 126 is just one of a variety of bacteria --
Like the one attacking L.
Therefore, it represents another potentially effective bacterial element added to the bacterial plain library, which can currently be used to inhibit the growth of pathogens.
Robert Buchanan, senior scientific advisor and director of the Office of Science at the FDA\'s Center for Food Safety and Applied Nutrition, agrees with Klaenhammer\'s observation that the bacterial element, in particular nisin, has been shown to be
Buchanan is a team member of the first group to separate the bacteria-like bacteria 10 years ago.
\"It\'s interesting,\" he said, \"Although a lot of work has been done in this area, we see very limited number of users applying to the FDA for approval of bacterial elements, which is not available in this class.
\"Any application will be subject to the FDA\'s normal review of the classification of food additives, he said.
The second new technology involves the field of food packaging.
Whether or not the application of bacterial killers is included, food packaging is essential for safety and economic reasons.
Each food has unique requirements to ensure aging as slow as possible.
If the aging process can be slowed down, the shelf life can be extended.
The main means of achieving longevity is cold storage, sometimes combined with changing the storage atmosphere or removing mature hormone ethylene, for example by continuously delivering air to the product.
By extending the time when food is fresh and safe to eat, packaging enables products such as fresh vegetables to be transported at long distances-
This is an important consideration in an era when food supply must often cross the oceans and continents into the market.
To meet these needs,
The cost of being able to accurately match the breathing rate of packaged fresh produce food film packaging is food and packaging developed by researchers from the polymer manufacturing team of the Scientific and Industrial Research Organization Manufacturing Science and Technology Department of the Commonwealth CRC.
The film has been successful in the fresh
Stir with cut lettucefry mixtures.
The film aims to solve the dilemma caused by fresh produce continuing to breathe, absorb oxygen and release carbon dioxide after harvest.
Breathing can drain the starch and sugar stored in the food, causing the food to age.
Atmospheric modified packaging (MAP)
Is a general technology designed to create a beneficial atmosphere for storage within the polymer packaging film.
Its goal is to use the permeability of the film to control the atmosphere to change the breathing rate of specific foods.
When the food was originally packed in the film, the atmosphere inside was a standard air mixture.
But the flow of oxygen and carbon dioxide through the membrane barrier will soon become the best atmosphere for the food inside.
\"Most traditional plastics are high-
Respiratory foods like broccoli, \"said Greg Christie, director of research at CRC.
For food and packaging.
\"It is important that the oxygen level in the package never drops to a state of hypoxia.
If the polymer does not penetrate too much, the conditions may allow harmful bacteria to grow to an unacceptable level.
\"Over the past five years, Christie and his colleagues have developed a unique MAP technology that uses the principles of activation diffusion and capillary gas flow to improve and control the flow of gas in the film.
\"Our goal is to have a better way to bring gas into the packaging,\" Christie\'s said . \".
This film is made with a traditional manufacturing process, but is soaked with an inert particle that Christie\'s will only recognize as a food ingredient.
The heat in the production process or the weight of the roller activates the particles.
This process thins the film around the particle, changes the interface between the particle and the polymer matrix, creates an inlet that allows the gas to flow between the particle and the film, thereby increasing the overall permeability of the film.
The permeability of a basic type of film can be changed by changing heat, roller weight, or other factors involved in manufacturing.
For example, increasing the temperature at which the activation process occurs increases the permeability of the film.
Therefore, the packaging staff can customize the film to maximize the life of a specific product.
The film itself is a common commercial polymer.
Sealed, printable, smooth and transparent.
The map method will apply to any Mono, Christie says.
Or multi-layer polymer this will enable packaging manufacturing companies to reduce or eliminate the need to maintain a large amount of plastic, as it can simply activate individual inventory packaging according to the breathing requirements of the product.
\"I don\'t know if this is revolutionary, but it could be an evolutionary progression,\" said George Sadler . \" Professor of food production and American scientists at Illinois Institute of TechnologyS.
National Center for Food Safety and Technology Summit-
Argo, Illinois is a consortium of food companies, university scientists and FDA.
\"If it is done cleverly, this method can establish a microscopic static balance that inhibits microbial growth.
You never want to lift the packaging to an oxygen-free level because you are in danger of producing garbage
Product and create an environment suitable for the growth of anaerobic organisms including [
\"Sadler notes that the general concept of breathable film has been around since the 1920 s, and Australia\'s initial interest was to find a way to ship lamb bodies overseas.
He believes that the current feature of custom movie penetration to match food will be a big advantage for this version of the map.
CRC for food and packaging is now moving map technology to industry, with at least four companies considering licensing various uses for it, including medical and industrial applications, in addition to food packaging.
If the commercial version of food packaging proves promising, then fresh produce can be easily shipped to Asia, and the agriculture below should prosper.
Suggest ReadingGozukara Y, Corgan, Kristy.
Breathable film packaging technology. Chem Aust (in press).
Jack R, Wan J, Gordon JB, Harmark K, David son BE, Hillier AJ, Wettenhall REH, Coventry key MW, Coventry MJ.
Chemical and antibacterial properties characterized by piscicolin 126, bacterial toxin production carnobacerium piscicola JG126.
Appl environmental microorganisms 62 (8):2897-2903(1996). Muriana PM.
Control the bacterial element of L. Liszt in food.
J Food Prot, 1996 Supplement: 54-63.
Schlingjie U, Gessen R, Hall sapafir WH.
Potential of antibacterial microorganisms and bacterial elements in food preservation.
Development Trend of Food Science and Technology164 (1996).