RAPID TESTS FOR FOOD INFECTION-WILL THEY EVER REPLACE CULTURE TESTS?

Food-borne infection episodes are becoming more and more conspicuous by their recurring occurrence in countries like the US and fast detection and identification of the contaminant is a high priority area of interest to the industry. Conventional culture tests take at least 24 hours though in many cases it may stretch to 3-5 days. As the volume of production is increasing day by day due to growing demand for processed foods, it is next to impossible for the industry to organize culture based diagnosis and this is pushing the scientific community to evolve quick tests as a part of the safety protocol for helping the industry. There are a few quick tests available now which can give results under an hour and these are being increasingly deployed in the industry. But there is no unanimity whether such quick tests can be solely depended upon and the conventional culture tests can be dispensed with totally. Here is a critique on this vital issue which needs to be resoled quickly for a universal regime acceptable o all the stake holders.  

"Tests for food-borne pathogens in which a culture is not grown in a lab may be necessary for produce companies, but they can't replace traditional culture tests, industry leaders and government officials say. Non-culture diagnostic tests have been around since the early 1980s, said David Gombas, senior vice president of food safety and technology for the Washington D.C.-based United Fresh Produce Association. But there has been a recent push, Gombas said, to use them to replace culture tests that the Centers for Disease Control and Prevention, the Food and Drug Administration and other agencies and organizations rely on to accurately diagnose cases of salmonella, E. coli and other food-borne illnesses. That trend was highlighted in a recent article in Scientific America magazine, which found that many clinics and state-run labs are turning to nonculture tests, which are faster than culture tests. They're faster, but are they better? "Right now, the answer is no," Gombas said. "CDC, FDA, and those in the produce industry I talk to — they want a live bug." A live bug is the result of growing a culture, which can take 18 to 24 hours in a lab, Gombas said. Some of the rapid non culture tests, by contrast, can be done in 20 minutes. For many fresh produce companies, like Earthbound Farm, San Juan Batista, Calif., rapid non culture tests are a necessity, said Will Daniels, Earthbound's senior vice president of operations and organic integrity. "Without them, we wouldn't be able to do what we do," Daniels said. "A culture is a three to five day process. We can't fit that into our system." Earthbound Farms tests every product it ships. If it relied on culture tests and had to wait three to five days to ship, it would need to have five to six days' worth of inventory on hand at any given time, Daniels said."

There is point in the argument of the industry that it cannot hold on to huge stocks of foods in their warehouses, waiting for the results of culture tests to arrive before releasing into the market and naturally inventory management can be a nightmare, especially for large manufacturers, affecting their economical viability. At the same time consumer safety is sacrosanct and cannot be compromised at any cost. Probably safety scientists may have to evolve some sort of empirical correlation between quick testing regime and frequency of culture testing to make sure that the system s absolutely reliable. It must be admitted that quick tests are possible only for known pathogens and as and when new bugs arrive, culture tests are inevitable to identify them. Considering the enormity of the problem, food industry should not rely entirely on modern quick tests and do way with conventional diagnostic tools!

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

RAPID DETECTION OF FOOD PATHOGENS-NEW DEVELOPMENTS

Food poisoning due to microbiological contamination is getting increased attention these days with billions of dollars of tainted foods being recalled from the market by the food industry due to strong suspicion about their safety. Traditional microbiological assays to identify contaminating pathogens used to take days together before any definite conclusions can be drawn putting high economic burden on food industry besides making the food processing a high risk area of investment. The most recent pathogen driven food poising episode occurred in Europe affecting hundreds of people and forcing recall of the tainted sprouts across the continent. It took almost a month for the safety authorities to pin point the nature and the source of contamination, highlighting the logistical problems associated with monitoring food safety. One of the key factors that can expedite identification of the contaminant(s) is the rapidity with which assays can be performed and recent development of a molecular detection system augurs well for the quality control laboratories in the industry as well the safety vigilance agencies all over the world.

"The 3M Molecular Detection System delivers highly sensitive results by targeting and amplifying nucleic acid in enriched samples. The automated technology has been evaluated with a variety of food types, including produce, meats, processed foods, pet food and food processing-related environmental samples. The instrument is sleek and compact -- taking up less counter space than a laptop computer, making it portable and adaptable to various lab environments. "Pathogen testing has now been made simple and affordable," said Niki Montgomery, 3M Food Safety global marketing development manager. "Food processors will benefit greatly from the system's affordable accuracy and fast time to results, minimizing downtime in the lab. Numerous organisms can be tested in a single run and it was designed to help our customers perform fewer repeat tests and make critical decisions faster." Three assays available, validation efforts underway. As part of the 3M Molecular Detection System platform, individual, pathogen-specific assays, or procedural tests, will be sold as a test kits. Each assay test kit uses the same software interface and same DNA extraction protocol for testing between one and 96 samples per run. Assays for Salmonella, E. coli O157 (including H7) and Listeria are available immediately; a test for Listeria monocytogenes is expected in early 2012. 3M will continue to invest in developing a full portfolio of pathogen testing solutions to address customer needs. Independent laboratory studies with the 3M Molecular Detection System are currently underway to pursue global method recognitions. "In our evaluation of the Listeria species assay, we liked the small footprint of the system as well as the quick delivery of results after sample enrichment," said Dr. Martin Wiedmann, a professor in Cornell University's Department of Food Science who studied the system's analyses of samples taken from meat-packing, seafood processing and retail locations. "This system definitely illustrates the potential of isothermal methods for rapid detection of foodborne pathogens."

The claim that this method is very reliable and accurate besides taking much less time, probably will make it very popular provided the capital and recurring costs are affordable to the industry. Another way of looking at it is that even if the cost is some what stiff, it is more preferable to invest in this gadget rather than bearing the full economic burden of a possible recall. Though availability of such sophisticated assay systems can significantly reduce food poisoning episodes, consumer will still have to be on guard when it comes to trusting industrial foods absolutely and as a general precaution more care needs to be taken when "cold foods" from the refrigerated section of the super market or Delis are consumed.

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

FOOD INFLATION IN INDIA-THE RBI "DIAGNOSIS"

Who is not worried about the food inflation that is going up and down every week between 6% and 10% as per government "estimates"?. But the average "aam aadmi" has different experience when they go to buy their daily needs of food materials like pulses, oil, vegetables and fruits with the prices ruling at high levels persistently. During the recent discussion in the Parliament on this subject one could see clearly the GOI mindset in laying the blame for the domestic food inflation on the door steps of Europe and Global system! A small dip in inflation during the last week of November was highlighted as a trend of declining inflation, probably ignoring that only prices of Onion and Potato registered a decline in price due to fresh arrival in the market which brought down the GOI inflation figure slightly. RBI, country's Central Bank has correctly identified the reason for inflation by pin pointing that "drivers" of inflation to day are protein foods, fruits and vegetables and due to widening gap in the demand-supply situation vis-a-vis these foods, inflation is bound to persist if not to go up, unless corrective measures are taken immediately. Here is a take on this latest twist to the food inflation crisis in the country.   

"Reserve Bank of India deputy governor Subir Gokarn said that the drivers of food inflation has changed from the pair of sugar and cereals during the last four decades of the previous century to proteins and fruits and vegetables during last four years. He also asserted that the situation of persistent high food inflation warrants monetary policy responses to keep the overall inflation in check. Mr Gokarn was delivering the Kale Memorial lecture at the Gokhale Institute of Politics and Economics (GIPE) today on 'Food Inflation: This Time It's Different.'' "The more worrying attribute of food inflation is persistence. In the four decades in 1960's, the drivers of food inflation were cereals and sugar with a supporting role being played by proteins and fruits and vegetables in the second half of the period,"said Mr Gokarn, adding, "While contribution from proteins has gone down somewhat in 2011-12, which is the basis of the declines we have seen in food inflation in the most recent date releases, the pressure from fruits and vegetables have sustained." Mr Gokarn said on the demand side that people eat better as they get richer is a simple assertion. But on the supply side, we have problems. The productivity of pulses has oscillated around 600 kg/hectare for the last decade and a half. "There are several states, in which pulses may constitute an important part of the typical diet, whose productivity is significantly below the national average. If overall productivity is to be improved, a strategy which focuses on the specific bottlenecks in these states is probably the best way to go about it,"he said. Mr Gokarn pointed out the rising wages of agricultural labour and the stocks of agricultural commodities as two important factors exerting influence on their prices. "Wages rising faster than productivity can only result in rising prices, if producers cannot substitute other inputs for labour. There is important relationship between price dynamics and stocks. Periods in which stocks have been high, show relatively low rates of price increase," he said. Lastly, he pointed out the declining trend in the long period average (LPA) of monsoon rainfall. "This means that normal monsoons are delivering less water than in the past. He said that the implication of persistent supply pressures on the economy are not very good for maintaining balance between fast growth and low inflation. "While transitory episodes of food inflation do not warrant a monetary policy response, there are strong justifications for acting in the face of more persistent ones, if the objective is to keep overall inflation in check". 

It is not clear why GOI has suddenly pitched for FDI in the retail sector when food inflation is showing signs of getting out of control. Does GOI really believe that promise of investment in retail by the global retail chains will increase agricultural and horticultural productivity? GOI has to answer a lot as to why the pulse productivity in this country still stagnates at a shameful figure of 600 kg per hectare! By shirking its responsibility to bestir the agricultural sector through appropriate reforms and infrastructure augmentation, GOI has exposed its weakness in taking and implementing decisions for the good of the farmers and consumers in the country. Even now there does not appear to be any urgency to address these issues in a sincere and determined way and in stead more noise is being made with no substance to fool the aam aadmi through rhetoric and high decibel sound bytes!

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