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Perspective On: A Food Testing Lab

The U.S. imports food from more than 150 countries and territories. Much of it is fresh produce and seafood, which can carry microscopic contaminants. While these contaminants become smaller and more sophisticated and food safety laws become stricter, food testing laboratories are coming up with new technologies and processes to detect chemical toxins before they reach the consumer.

by Bernard B. Tulsi

More Food Testing Capacity Needed in the U.S. and Overseas

Acting on the urgent need to reinvigorate food safety measures in the United States, the Obama administration moved recently to strengthen government agencies charged with monitoring and ensuring the safety of the country’s food supply. Along with the recent appointment of Food and Drug Administration (FDA) Commissioner Dr. Margaret Hamburg, President Obama established a cabinet-level panel, the Food Safety Working Group, which will recommend ways to enhance food safety laws and engender cooperation among the various agencies that list food safety among their responsibilities.

Lisa Shames, director, U.S. Government Accountability Office, in an address to the second annual Global Food Safety Policy Forum—convened by Waters Corporation in Washington, D.C., in October 2009—noted that the U.S. imports food from more than 150 countries and territories. Imports make up 15 percent of the country’s total food supply, 60 percent of the fresh food and vegetables, and 80 percent of the seafood. The forum brought together policy makers and food industry experts from around the world to discuss pending legislation and potential solutions to improve food safety in the United States and worldwide.

In late July this year, the United States House of Representatives passed the Food Safety Enhancement Act based on a bill authored by Rep. John Dingell (D-Mich.), which will give the FDA greater capabilities to fight food-related outbreaks. Similar moves are afoot in the Senate, and in mid-March a bipartisan group including Sen. Richard Durban (DMich.) and Sen. Judd Gregg (R-N.H.) proposed the Food Safety Modernization Act.

Gerry Broski, food safety marketing director with Thermo Fisher Scientific, says the food safety and testing community continues to advance standards and concerns over the safety of our global food supply. “Europe and Japan have taken leadership roles in food monitoring. They have aggressively established very low maximum residue limits and are very concerned about the long-term health effects of what people consume. In the U.S., we have new legislation pending in Congress that will change the way food safety is regulated. China has a new Food Safety law implemented earlier this year. While you cannot “test-in” safety for food, you can mitigate the risk of inherent and deliberate contamination through testing and analysis,” says Broski.

Despite effective legislation, it can hardly be expected that incidents involving food contamination will be eliminated. “We can put good systems in place, and along with better mechanisms for control, we can minimize the occurrence of these events, but they will never go away completely,” says Paul Young, senior manager, Chemical Analysis Operations, Waters Corporation.

He says that the lab testing capacity needed for food analysis is far from adequate here in the U.S. as well as overseas. U.S. agencies such as the FDA have been under-resourced, and they have seen their net funding decrease over the last five years.

Young adds that in foreign countries, there is a lack of clarity about U.S. safety requirements for imported food at the moment. As a result, there is a need for U.S. authorities to inform trading partners about standards and to help them build the necessary capacity to test in compliance with those standards, he says.

“The alternative is to use the same approach that, for example, Japan has adopted, where they test a high percentage of the imports themselves. That is not the most efficient approach— it should be a partnership, and if the U.S. authorities work with their trading partners and help them to establish effective testing programs, then they can ensure that the food is being tested before it leaves the exporting countries,” says Young.

To be sure, for some time now a number of analytical instrument designers and developers have been building, tweaking and improving the tools that have proven indispensible in food safety laboratories. The most recent iteration of new and improved tools for food testing was displayed at the 123rd AOAC INTERNATIONAL Annual Meeting and Exposition, which was held mid-September 2009 in Philadelphia.

Joe Romano, senior manager, Chemical Analysis Business Development with Waters Corporation, says that sample preparation is a key concern in modern food testing and featured prominently among the innovations demonstrated at the AOAC meeting. “We are seeing a large request for these tools, as that seems to be a bottleneck. One of the tools we are offering for this is known as DisQuE, which is a dispersive technology known in the field as a QuEChERS technique.

DisQuE enables multiple pesticide residue analysis on a variety of fruits and vegetables and allows a generic type of sample cleanup. It is fast, cheap and easy to use and works well with LC-MS/MS technologies, and when combined with UPLC. The DisQuE kit consists of centrifuge tubes and preweighed sorbents and buffers compatible with official methods. It is part of a streamlined process— sample preparation through analysis, data generation and specialty software for reporting the results.

Turning to the subject of beverage analysis, Romano notes that just two years ago there was considerable concern about pesticides in soft drinks in India from two large manufacturers of beverage products. “There was a rapid reaction to that concern that led to the development of methods and enhanced capabilities within the two organizations to deal with the issue,” says Romano

There are similar concerns in the area of new ingredients. The fastestgrowing areas in the food manufacturing business are functional and health foods and one of the largest categories is artificial sweeteners, according to Romano. A new sweetener, stevia (also known by other names), which is a natural product derived from a plant source, was introduced to the market by several food manufacturers. Stevia, which is FDA approved, has zero calories and is a thousand times sweeter than sugar—so it provides a number of health benefits.

“When products claim that they contain stevia, there is a need to be able to verify that the correct ingredient is present. As a result, we have worked with some manufacturers to develop QC methodologies, based on the profile of different isomers of stevia, to test for this natural sweetener,” says Romano. The test, called the BEH Glycan, which was designed on brand-new chemistry based around UPLC particle technology, enables the detection of the isomeric forms of stevia in about three minutes using ultraviolet technology. This test is valuable for QC and for ensuring that food labeling claims are met.

Broski believes that the melamine contamination outbreaks have raised the level of awareness within society that our food supply must be constantly monitored for both known and unknown contaminants. He notes that melamine is a persistent chemical, which is in the environment, and as a result it will remain in the food chain for some time.

“Industrial chemicals constitute one large area of contaminants that we will have to continue look out for— and another important category is mycotoxins. Mycotoxins are generating a lot of international interest, with many organizations devoting considerable attention and resources to this area,” says Broski.

Changes in climate appear to cause fungi to produce toxic metabolites. They grow on a variety of beans, grains, and nuts, where they create toxins that people can ingest with unpleasant consequences,” says Broski.

Thermo Fisher Scientific offers a wide range of products for the detection of numerous contaminants— chemical residues, pesticides, veterinary drugs, trace elements, natural toxins and pathogens, among others. The company is also engaged in the development of tools for food profiling where the objectives are traceability, authenticity and the origin of ingredients.

Broski sees considerable value in screening or profiling food. “The question is what should a particular food look like? Anything that does not fit the normal profile has to be considered a contaminant. So what the labs are looking for and what people in technology are converging on are products that can rapidly screen food for suspected contaminants.

“Our Exactive high-resolution mass spectrometer uses Orbitrap technology to enable a wide dynamic range and resolution of up to one part in a hundred thousand. With these capabilities, the Exactive is able to find contaminants that are not detectable by other means. This product also has powerful targeted and non-targeted analysis capabilities, making it an attractive tool for contract labs where throughput and cost per sample are key considerations.”

Broski notes that Thermo Fisher also has a product that addresses the sample preparation side of the workflow— the Transcend system, which uses turbulent flow chromatography to reduce the burden associated with sample preparation, while increasing throughput.

“What we are seeing now is what was once considered research-grade instrumentation becoming the routine. This is most noticeable in areas where there is a need to detect increasingly smaller traces of contaminants and for authenticity. An example of this is the use of isotope ratio mass spec instruments being used in food authenticity applications.

“New standards are constantly being developed, new food ingredients and delivery systems such as nanoparticles are being engineered, maximum residue limits are being revised, new contaminants are being detected, and the sensitivity of the detection instruments is increasing. Given these dynamics it is clear that food safety will remain an area of intense interest for the foreseeable future,” says Broski.

Applied Biosystems established an Applied Markets division a few years ago to leverage technology that was developed for basic research—genome sequencing along with a variety of other basic research tools—and put them into real-world applications including food analysis, according to Phil Pielage, director of sales for Applied Markets at Applied Biosystems.

“In the food area, we have had some partnerships over the years, including an exclusive relationship with DuPont back in 2005. Within the last year and a half we have gone directly to the market within the food industry,” says Pielage.

“The main concept is to take classic microbiological techniques, which really haven’t changed in 200 years, and leverage them into a molecular basis. With the genomes of most of the organisms sequenced, we have been able to use that information to create effective tests based on DNA, which increases the sensitivity of the analysis,” says Pielage. He explains that this allows the specific targeting of organisms based on their DNA match.

“That is the foundation that has enabled us to develop a variety of tests that have more sensitive assays, increased turnaround times (making tests fast enough to be completed in a single shift) and greater specificity (that allows the detection of pathogens— even different strains, if necessary) with a high degree of confidence,” he says.

Commenting on the overall preparedness to address chemical contaminants in food now, Andre Schreiber, technical marketing manager for Food and Environmental Testing, Applied Biosystems, says, “Government agencies and food testing laboratories are way more ready to identify contamination before they cause problems than they have ever been in the past.”

Turning to Applied Biosystems’ offerings to test for chemical contaminants in food, Schreiber says, “Our portfolio of tools for the food testing laboratory is based on liquid chromatography technology together with mass spectrometry. These tools analyze organic molecules in foods and residues that are not supposed to be present.

“We have these instruments on different performance platforms, depending on the concentration to be detected. Our instruments vary in cost, depending on applications, but we also have highly sensitive instruments, which can be used for ultra trace analysis. The common characteristic of all our instruments is that they are very fast, which is especially important in residue analysis, where laboratories need to detect hundreds if not thousands of chemical residues in a single analysis.”

Schreiber says that in the course of the last two years there were two important driving forces. “It had become clear that increasingly labs have less than the required expertise to move into food testing, though they wanted to enter the field because it is a growing concern.

“So we developed innovative tools, especially software, to make it easier for them to use our equipment. We also developed a system that made it possible to download methods for analytical techniques, which can then be loaded into the software of a mass spectrometer, and very quickly achieve the stage where reliable results can be generated. This required making everything easy to use and ready to go,” he says.

The second initiative was for more established laboratories, which are under strong pressure to turn around samples faster—where there is a strong demand to get results out quickly or there is a need to earn more revenue. “For this group, we developed a system with two liquid chromatography streams going into a single detector to double the throughput. This is very important in contract laboratories,” he says.