FOOD SAFETY DEVELOPMENTS-COLD PLASMA, A POTENTIAL DECONTAMINANT

By far the most critical safety problem being faced by the consumers in many advanced countries is food poisoning caused by pathogenic bacteria like virulent E,coli species, Salmonella and listeria. The products getting contaminated include meat, vegetables, dry fruits, nuts, poultry products etc and fatalities vary in different episodes. In Europe the fenugreek sprout contamination with Listeria claimed several lives before even it is identified and source of supply traced. It is ironical that these deadly infections are more or less confined to rich countries where the safety standards are very stringent and the vigilance infrastructure is most modern. One interesting fact that emerges from a close scrutiny of food safety episodes is that almost all of them involved cold foods which cannot be heat treated because of their vulnerability to significant quality changes not accepted easily by the consumers. Paradoxically one of the most effective technological tools available to "cold sterilize" such foods, gamma radiation is not availed off by the industry due to nonsensical labeling rigidity on the part of the safety authorities. Another alternate option that may soon be available to the processors is the cold plasma technology which is undergoing tests to establish its technical feasibility vis-a-vis food sanitization. The claims being made by the scientific group that is pioneering the development are contained in the report below.  

"May was a rough month for fresh produce. Alfalfa sprouts, bagged salads, and diced onions were recalled because of possible listeria contamination, while baby spinach and papayas were recalled because of possible salmonella contamination. It's enough to make one scout for something new in food safety systems. And Brendan Niemira is working on something. Niemira, lead scientist at the USDA's Food Safety and Intervention Technologies Eastern Regional Research Center in Wyndmoor, Pa., has been studying cold plasma for nearly a decade. The process uses electricity and a gas — such as oxygen — to deactivate contaminating microbes on meats, poultry, fruits, and vegetables. Niemira and his colleague Joe Sites have treated a variety of foods — including almonds, apples, cantaloupe, lettuce and tomatoes — with cold plasma and produced multi-log reductions of E. coli O157:H7, salmonella and listeria. While cold plasma already is used to clean electronics, bond plastics in manufacturing and bind dye to fibers in textile production, its potential remains untapped in the food industry. "Anytime a technology is being developed, it's only going to be used in the industry if it shows some significant advantages," Niemira said. "Cold plasma is a waterless sanitizing process with no chemical inputs, so it's got some attractive points. The big key right now is to develop the technology so that it gives a solid level of sanitizing antimicrobial effects without unwanted side effects. That's the kind of thing that might lead an interested party to petition the FDA." Niemira said that in cold plasma trials with apples and almonds there were no changes in the product's appearance. Another advantage, he said, is the level of efficacy. While most chlorine rinses will give one or two logs of surface sanitization, Niemira said cold plasma systems have been shown to give three or four logs in trials".

As the development has yet to come out of the laboratory of the scientists concerned, it may be quite some time before technological facilities are designed and conditions standardized on a commercial scale. The fact that cold plasma sterilization has already become an industry standard for sanitizing electronic goods and bond plastics and may get accepted, to start with, for sterilization of food machinery surface, conveyor belts etc in the food industry. As multi log reduction in pathogens has been demonstrated using cold plasma, its efficacy or reliability may not be questioned. The present sanitization procedures use high volumes of water, besides chemicals like chlorine even to get a 2 log reduction of pathogens and there fore food industry is likely to accept the new technology as and when it is ready for commercial level operation. Of course investment cost and the recurring expense in using the technology may eventually determine its fate.  

V.H.POTTY

http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com

UV TECHNOLOGY FOR FOOD DISINFECTION-NEW CLAIMS

Keeping the food from harm's way is a continuing challenge for the industry in spite of enormous success in evolving a multitude of disinfection technologies during the last five decades. Classically the traditional thermal pasteurization still rules the roost though the technique to generate heat may vary depending on the technology one talks about. With the advent of HTST/UHT technology which is being used by Tetrapack and other companies, heat damage to the quality of food processed has been greatly minimized though it is not avoided completely. Quest for non-thermal processing has resulted in development of modern technologies like Gamma Radiation, High Pressure Processing and a few others which are now being commercialized though on a slow pace. Ultra Violet light certainly has high disinfecting potential but its use is restricted more or less to making water pathogen-free. Now comes the news that new technologies are on the anvil exploiting the kill potential of UV light for commercial pasteurization of liquid foods like wine, fruit juices, milk etc. Here are some details about this latest development 

"The production of environmentally friendly, sustainable, chemical-free food continues to challenge the food industry, spurring the development of alternative novel food processing techniques that are more sophisticated than traditional practices and better for the environment. Ultraviolet light is one of these emerging solutions being used in food technology as a physical preservation method in food processing to purify microbiologically sensitive liquids such as wine, fruit juice and milk. This is according to US-based research scientist and world-renowned ultraviolet light in food technology expert, Dr Tatiana Koutchma, who was recently hosted by SurePure, the global patent holders of the world's first UV-C photopurification turbulator technology, to lecture the Microbiology Research Group students at the University of the Western Cape on the benefits of novel processing technologies other than heat, including UV light. She says that the use of UV light can not only lower microbial infestation and obviate chemical degradation of foods and the environment, but that it can improve the functionality of food, too, by enhancing fruit phenols and preserving antioxidants"

How far the above report is commercial promotion and how much the technology described above is realistic cannot be ascertained unless there are verifiable user experience regarding its efficacy and reliability. Probably the manufacturers of the so called "UV Photopurification Turbulator Technology" may have to do a lot of leg work to convince the user industries that it can "improve chemical, physical and microbiological" quality of foods treated, as being claimed. The assertion that the nutritional quality is enhanced because of increase in polyphenol content also needs more scientific evidence. No doubt UV technology can compliment the conventional pasteurization processes but how far it can become a stand alone technology remains to be seen.  

V.H.POTTY
http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com

FOOD PLANT DISINFECTION-THE OZONE 'ROUTE'

Ozone, the triatomic allotrope of oxygen is one of the most destructive oxidative agents known and has many industrial uses. Its importance to food and beverage industry is increasingly being realized and ozone is the most widely accepted water disinfectant to day. The high oxidative power of Ozone ensures that all contaminating microbes are decimated, making the product safe for consumption. Compared to Chlorine, the well established disinfectant used currently in most public protected water supplies, Ozone does not produce the dangerous organochlorine compounds or leave any residues due its decomposition to oxygen. Added to this, Ozone can also remove higher levels of Manganese, make cyanide less toxic and decompose urea present in water..

"Middleton said that an added benefit of using ozone in the food and drink processing sector is that it is environmentally friendly, with any residual ozone decomposing to oxygen. In terms of vapourised hydrogen peroxide, she added, it is also rapidly broken down to water vapour and oxygen, and thus leaves no problematic residues.She said that these whole room disinfection techniques can be used daily or part of the periodic cleaning and disinfection procedures that occur monthly – it depends on the output of the processor involved or the level of decontamination required.She said the methods might also only be employed when decontaminating an area after a pathogen contamination incident".

Unlike Chlorine, Ozone needs to be generated on site and generators of different capacity are readily available, compact in size. Where ever power is easily available or cheap, Ozone is the preferred choice as a disinfectant. Ozone has bad as well as good credentials when it comes to human health. Its presence in the upper atmosphere saves man from the dangers of UV exposure from the Sun while as a pollutant near earth's surface it is a health hazard. As Ozone at concentration as low as 0.2-0.3 ppm can achieve disinfection, its use is not considered a hazard for users.

V.H.POTTY

http://vhpotty.blogspot.com/

http://foodtechupdates.blogspot.com