VACCINES FOR MEAT ANIMALS-AWAITING COMMERCIALIZATION

Meat industry is notorious for its vulnerability to dangers from deadly pathogens like Salmonella, virulent E.coli and others. Even if the sanitation regime that is required to keep the carcass free from microbial contamination is scrupulously deployed, the chances of cross contamination is still possible. If at all any sector of food processing faces high risk during its operations, it is the meat industry. Repeated pleas to allow low doses of gamma irradiation for maintaining freedom from pathogens have not yet been heard sympathetically and the risk factor remains as high as ever even to day. Against such a bleak background comes the news about development of vaccines that can be used for protecting animals till slaughter from the dangerous vectors. It is an interesting development that must please the industry to no end. Here is the take on this issue.

"Imperfect" but potentially effective technologies to control foodborne pathogens in beef pre-harvest are now available to government and industry, according to experts at a Nov. 9 meeting on pre-harvest pathogen control convened by the FSIS, the Animal Plant and Health Inspection Service, and the Agricultural Research Service. But can they be usefully implemented? A number of vaccine technologies have demonstrated a significant impact in reducing levels of E. coli 0157 and Salmonella bacteria detected in bovine feces pre-harvest, said Guy Loneragan, PhD, professor of food safety and public health at Texas Tech University in Lubbock, who presented the opening address at the meeting. For example, Epitopix/Pfizer Animal Health's SRP vaccine has shown a 40% to 60% reduction in Salmonella levels in feces in various commercial studies—and even more in so-called "high shedders." "These technologies have repeatable and predictable, if imperfect, efficacy. Even given that imperfect efficacy, if we have broad adoption of these technologies, we can have quite a meaningful public health impact. But how can we develop an environment that fosters their adoption?" The burden cannot be placed solely on producers, Dr. Loneragan said. "We have to find ways to pull these technologies through the system, not just at the packing plant level but at the retail level as well. Retailers need to develop a coordinated plan with packers, suppliers, and producers to share the costs and rewards of these technologies." At the meeting, industry representatives and other experts also suggested that more open testing of the vaccines in the marketplace is needed—and called for the FDA and USDA to expand licensure. "Right now, we have one vaccine that's conditionally licensed," said Dr. Loneragan. "But the conditional license comes with real barriers to adoption, such as a 60-day slaughter withdrawal. If there were a full license for these vaccines, sponsors could do studies that could show support for a shorter withdrawal period, which is much more practical. There has to be a mechanism by which the vaccines can move forward to full licensing and the industry can look at them in a more open and complete way."

One of the drawbacks cited against the vaccines is that they are not 100% effective, the degree of protection being in the range of 40-60%
which raises doubts about their overall impact under field conditions. Besides the conditional approval given to them stipulates that animals cannot be slaughtered for at least 60 days which naturally can put some burden to the industry in maintaining large stocks for long periods. If this work is carried forward there is good possibility that a multi-valent vaccine may emerge eventually that can take care of most predominant pathogens which are causing sleepless nights to the meat industry. In stead of leaving every thing to the industry to near the burden, Government agencies must play an effective supporting role in expediting such developments which will have far reaching benefits to the consumers.

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

SYNERGISTIC EFFECT OF RADIATION AND ANTIMICROBIAL ADDITIVES-EVOLVING A NEW STRATEGY

Is there any scientific reason for the food industry to shun gamma radiation technology for preservation of foods? Apparently not. Fear of consumer backlash is being touted as an excuse for practicing this clean technology and the food authorities also are responsible for this contradiction because of their insistence on labeling radiation preserved products differently from those processed by other technologies. Whenever a product is labeled distinctly as "irradiated" most consumers will think twice before buying them because of the normal human psychology of suspicion! One may ask why the same countries, allowing GM foods to be marketed without any label declaration, are insisting on irradiated foods to be labeled separately? The on-going research to reduce the radiation dose to as be low a level as possible will have a meaning only when this technology becomes a universally accepted one.

"The contamination of poultry products by foodborne pathogens such as Listeria monocytogenes is an important cause of human foodbornedisease. This has significant economic costs to the food industry and can result in a loss of consumer confidence and damage to market brands. The use of ionizing irradiation has been approved by the US FDA for raw and frozen poultry at maximal dose strength of 3 kGy. This dosage can significantly reduce the numbers of pathogenic and spoilage bacteria and can also help ensure safety, shelf-life stability and sensory quality. However, irradiation can also result in chemical changes in meat products, leading to off-flavors and odor's, decreased tenderness and the formation of a pink color that can persist after cooking. The degree to which irradiation affects quality characteristics of chicken meat is dose-dependent. The addition of natural compounds with antimicrobial activity may allow the use of lower irradiation dosages, thus improving the quality and consumer acceptance of irradiated meat. Multiple microbial intervention strategies used as hurdle technologies can produce synergistic inhibitory effects. Natural antimicrobials include plant extracts such as green tea, which contain phenolic compounds, and tartaric acid".

One of the reasons for scientists to pursue this line of research could be to make the consumer feel that a low dose of radiation carries much less risk, if at all there is one, compared to what is being recommended. Whether one likes it or not, food industry will have to adopt irradiation technology eventually if the present trend of food poisoning and massive market recalls of foods, especially meat based ones, are to be avoided. If microwave processing has established as a technology in the thermal preservation area, cold sterilization can be achieved more easily through irradiation. The fact that sterilization can be ensured after packing without raising the temperature of the contents is too attractive an option the industry can ill-afford to ignore for long.

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