Food Safety Magazine

INSIDE MICROBIOLOGY | June/July 2004

Advancing the Food Safety Agenda

By An interview with William H. Sperber, Ph.D.

Advancing the Food Safety Agenda

Hired in 1972 by Pillsbury to conduct the first hazard analyses for consumer food products, Dr. Sperber has been at the forefront in the advancement of the Hazard Analysis and Critical Control Points (HACCP) system of food safety. During his 36-year professional career, Dr. Sperber has worked for three major food companies—Best Foods, Pillsbury, and Cargill; and has become one of the world’s experts in controlling the microbiological safety and quality of foods. A former chair of the IFT Division of Food Microbiology and the Food Microbiology Research Conference, Dr. Sperber has been appointed five times by the U.S. Secretary of Agriculture to the National Advisory Committee on Microbiological Criteria for Foods, where he has been a key contributor to the committee’s HACCP and Listeria monocytogenes documents. In 2000, he was appointed to the FAO/WHO roster of experts for microbiological risk assessments. Now semi-retired, Bill is a strategic advisor to Cargill’s food safety program, where he was most recently senior corporate microbiologist.

A 2004 Food Safety Magazine Distinguished Service Award recipient, Dr. Sperber spent some time with us to share his expert insights into the issues and trends in food microbiology today.

FSM: In your experience, Dr. Sperber, what are the most significant changes the food industry has made in the last 30 years with regard to how companies approach microbial hazards and food safety?

Sperber: There have been a number of changes, but perhaps the most significant change has been the way in which the food industry responds to new foodborne hazards. I saw how the industry responded back in the 1960s to foodborne illness outbreaks associated with Salmonella and Staphylococcus in processed foods. Those responses were quite slow compared to the responses I’ve observed since the early 1980s when Listeria monocytogenes and E. coli O157:H7 became recognized foodborne hazards. On the global scene, the first really significant outbreak of foodborne listeriosis occurred in 1981 and the first two outbreaks of E. coli O157:H7 occurred in 1982, but those were early warning signals, which typically don’t immediately precipitate major industrial responses. Looking at those developments over two decades, some might say the changes were slow but these were very broad ranging, very serious hazards that took a long time to understand and control.

Numerous “emerging pathogens” affected huge segments of the food industry in the past 20 years, especially meat and poultry, produce and dairy products. But the food industry as a whole coalesced around these two particular microbial hazards, Listeria monocytogenes and E coli O157:H7, and conducted a lot of research to come up with innovative interventions to control the hazards. The industry actually started working earnestly on Listeria monocytogenes control in 1986 and on E. coli O157:H7 in 1994. I think the industry responded more quickly and effectively because of the then-growing alliance between the food industry, trade associations and university research teams. You put these groups together and it is a powerful alliance. In fact, one of the American food industry’s greatest strengths is the scientific advancements in the detection, prevention and control of microbial hazards that we’ve been able to make based on the work conducted by our nation’s research universities. This model of cooperative research also has resulted in increased give-and-take between the food industry and regulators and more focused discussion of what effective regulations should look like.

This is the 30,000-ft. view of significant change in the industry with regard to our awareness of microbiological concerns and solutions. As we’ve worked on problems pertaining to pathogenic microorganisms in foods, we’ve also gained heightened awareness of other potentially catastrophic problems that are worse, including bovine spongiform encephalopathy (BSE), foot and mouth disease, and global zoonotic agents like SARS and avian influenza. These concerns make it all the more imperative for this powerful alliance of industry, trade associations and research universities to continue working together on the scientific-based food safety agenda. When I speak on other continents, I promote this well-established U.S. model to the South American and Asian nations that don’t yet have such models.

Uniformly, over the past two decades the industry has put even more attention on the basic food safety programs, such as Good Manufacturing Practices (GMPs), HACCP, sanitation and allergen control to great effect. The emergence of food safety departments and the corresponding food safety director/supervisor/manager titles within food companies is testament to the industry’s commitment to protecting consumers from foodborne illness.

FSM: HACCP has become a standard food safety program in most food companies, whether its use is mandated for their industry or not. How important is HACCP to a company’s food safety effort, and do you think we can improve upon it?

Sperber: In the European Union, HACCP is a mandatory food system used by all food companies, and it is safe to say that the overwhelming majority of U.S. food companies are implementing HACCP, whether mandated to do so or not. HACCP is very important to an overall food safety effort. I like to think of HACCP as the crowning jewel of a food safety program. However, as we’ve discussed before, HACCP cannot stand alone. It is not a total food safety program and it needs to be supported by a strong foundation of GMPs and good hygienic practices.

Do I think we can improve on it? Very definitely. There is a range of competency with which HACCP is applied and maintained throughout the industry and I see several weaknesses that can be improved. We can improve on the existing system simply by providing better training to people who are going to be monitoring critical control points and auditing HACCP plans and by better managing the HACCP systems, including better hazard analyses, documentation and recordkeeping. Lack of training and HACCP system management applies especially to the U.S. food industry, where HACCP is not mandatory for all food companies. Some companies may put together a HACCP plan just to say they have one, and whether through ignorance of how the system should be applied or possibly as a result of incomplete training, these companies devise a system that is marginal and less than wholly effective. When you compare foodborne illness outbreaks of 40 years ago with foodborne illness outbreaks today, almost every single one of them is caused by a failure of management to provide the proper resources—training, education, money for control measures.

Information technology (IT) in the form of software and data analysis systems can drive improvements in every area, including food safety and HACCP. For example, there is work being done to automate CCP monitoring, making it on-line using scanners, as well as ways to automate the data transfer from microbial test devices to enable processors to analyze historical trend data. Today, IT is a prominent part of all food plants in production and it is driving improvements.

The seven principles of HACCP also will evolve and change to address new challenges. When first published in 1971, the HACCP program model was comprised of just three principles. It wasn’t until the HACCP model was expanded in 1992, when both the National Advisory Committee on Microbiological Criteria for Foods and the Codex Ali-mentarius Committee on Food Hygiene published revised guidance documents, that HACCP included the seven principles we use today. So, in 27 years, we went from three to seven principles—a quantum leap. It is already 12 years since 1992, and I wouldn’t be surprised to see, certainly in the next decade, another few HACCP principles added. I would venture a prediction that Principle 8 will be on “Validation” because there are two important uses of validation in a HACCP plan and neither use is well articulated in the existing HACCP guidance document. The first use of validation is the need to validate process controls in Principle 3 when you are establishing critical limits, and the second use is in Principle 6, when you are using verification or audit activities to validate the accuracy of the HACCP paper trail. These will be incremental improvements on the existing system and a global consortium will effect the changes.

FSM: As a food microbiologist, you have seen the emergence of many pathogen prevention, control, detection and verification technologies. How does the availability of new technology aids processing companies in combating harmful microbes in foods?

Sperber: I think the new technologies available to the food industry to detect and verify the presence of pathogens in foods have become more rapid, sensitive, accurate and useful to us. For example, using the polymerase chain reaction (PCR) technique for the detection of pathogens is widely used at meat plants to assure compliance with regulatory requirements such as the absence of E. coli O157:H7 in beef trim or raw ground beef, and the absence of L. monocytogenes in certain ready-to-eat meat, poultry and dairy products.

The major advantage of PCR technology is that definitive results are obtained more quickly than is possible by using other technologies. Combined with pulsed field gel electrophoresis (PFGE) or ribotyping, PCR also is useful in conducting sanitary surveys of plant environments and process equipment to detect hot spots of specific pathogen contamination, and to enable development of effective corrective actions.

Such high-powered technologies are not necessary for general sanitation monitroing in a food production plant. Simpler technologies, including ATP bioluminescence and conventional microbiological plating methods, are practical and adequate for this purpose. For example, ATP bioluminescence tests and devices are very useful as sanitation indicators and they also are outstanding training tools for sanitation crews. It used to be that the QA technicians would come into the plant, take environmental hygiene samples for lab testing, and two days later they’d come back with a high count and admonish the sanitation crew. With the adoption of ATP systems as sanitation verification tools, that doesn’t happen any more—the sanitation department has been empowered. Sanitation personnel can easily use ATP systems themselves, get immediate results and actually correct cleaning problems very quickly.

The biggest improvement in any of these technologies is that we’re moving toward real-time measurements with which we can get an answer in minutes rather than in hours or days. For pathogens such as Salmonella, Listeria and E. coli, the industry has been very glad even to have really good test results in one day; maybe in 10 years, we’ll have a rapid test that can be performed in 10 minutes. We aren’t seeing that yet because there is the fundamental problem of being able to find one cell of a pathogen that is embedded in 100 grams of a food matrix. The question is, how do you get the one cell out of 100 grams of hamburger so that it can be detected by your instrumentation?

I don’t like the idea of any of the microbiological detection technologies being applied to test for the absence of pathogens because when it comes to assuring food safety nothing fails like finished product testing. That’s why we have the HACCP system. HACCP consists of two essential processes, one is product design and the second is process control. Process design means that you are literally designing food safety into the product and the process by which the food is produced. Process control is implementing food safety measures during processing operations to prevent and reduce microbial, chemical and physical hazards from adulterating product. We know that product testing does not work to detect low incidence hazards such as at 0.1% levels and that is exactly what we’re facing when we’re talking about Listeria and E. coli O157:H7 in meat and poultry products. It’s more effective to understand your process so that you can control and eliminate potential contamination. I don’t like to see the industry using any kind of finished product testing as a security blanket. We need to use our high-powered research results and talent to design products and processes that will eliminate or reduce potential hazards.

FSM: What do you think the next food safety challenges will be?

Sperber: When I started in microbiology 40 years ago, there were just a handful of foodborne pathogens. Today, we have easily five times as many. How many will we have 40 years into the future, and who knows what they will be? Luckily, we have a well-trained industry in place along with this powerful alliance of trade associations, universities, etc., to work on problems as they arise. The need to deal with emerging foodborne pathogens, or toxic chemicals or new allergens, for that matter, will always be challenging. Hopefully, we will be able to control most of these emerging issues with existing food safety systems. There will be some of them, however, that we will not be able to address with existing systems. The emergence of BSE is one example of a challenge upon which existing systems did not have any appreciable impact.

I think the major shift that we’ll see as far as food safety challenges for the future will be more among the lines of management and policy considerations. This is because of the continued and very rapid globalization of food trade and the increased probability of the global spread of foodborne illnesses. We will have to come up with global food safety rules that are based on common sense. I talked earlier about the powerful alliance of industry, trade associations and research universities, and we should put regulators in this alliance, as well. Regulators can contribute to such a global effort to produce food safety rules that are based on common sense.

As far as getting these rules in place, at the end of the day, the responsibility for food safety still resides at each plant that makes food. That’s where rubber meets the road, and I think that the multinational food companies around the world are a very positive influence in spreading and implementing best practices for food safety control. Today’s corporations are much better-intentioned than they are given credit for. It is in the interest of corporations to make safe and high quality food that people want to buy. It also is in their interest to spread these best practices into geographies that don’t yet have the culture and discipline of food safety that we have in the U.S. and Europe.

Categories: Contamination Control: Microbiological; Testing and Analysis: Microbiological