With new federal food safety regulations pending later this year, the industry finds itself dealing with an old problem: microbial contamination. The spring outbreak of bird flu only complicated matters. Microbiologically speaking, 2015 has been a busy year for food safety.
Bird flu pushed ingredient costs higher and made supplies scarcer but did not pose food safety dangers. The overwhelming majority of food manufacturers use processed eggs, and pasteurization, which all processed eggs must undergo, kills the virus involved.
But it’s not that simple with bacteria like E coli, listeria, salmonella and staph that cause human diseases or fungi like fusarium that give off mycotoxins that damage people’s health. The problem is, these microbes are present in the natural world, in the soil and on crops, as well as in the processing environment, through raw materials and the presence of human beings.
Mold, microbial bad boys
Among bakers and snack food processors, fungi pose the biggest concerns. The food industry knows this class of microbes by a more familiar term: mold. Bacteria and viruses cause health problems by infection; molds cause them by giving off metabolic byproducts known as mycotoxins (the poisonous compounds produced by certain fungi). Grain-based products are at the most risk from vomitoxins and aflatoxins. Both are poisonous when consumed in high doses by humans and animals.
Vomitoxin, often called DON (the abbreviation for its scientific name, deoxynivalenol), occurs in grains infected with fusarium mold, a.k.a. “head blight” or “scab.” This common mold grows on wheat, corn, oats, barley and other cereal grains and also generates fumonisin, another mycotoxin. Aspergillus molds produce aflatoxin, a known carcinogen implicated in liver cancer. It is of most concern in corn.
The Food and Drug Administration (FDA) restricts vomitoxin in finished products such as wheat flour to 1 ppm. Dry milled corn products can contain no more than 2 ppm fumonisin, with limits of 4 ppm in cleaned corn for masa and 3 ppm in unpopped popcorn. In its guidance document concerning fumonisin, FDA stated this mycotoxin is associated with a variety of health problems in livestock, but currently, no direct evidence suggests adverse health effects in humans. However, the agency set the action level for aflatoxins much lower: 20 ppb in all foods, including animal feed.
“It shouldn’t surprise us that food manufacturers have such a battle with microbes because they are out there in the environment,” said Shari Plimpton, PhD, vice-president and director of food industry programs, Center for Innovative Food Technology (CIFT), Dublin, OH, and a consultant to the Snack Food Association (SFA). “They are part of the scene, but we still need to try to keep them out of the processing plant.”
Weather and storage conditions affect mycotoxin development. FDA noted in its guidance documents that high levels are associated with hot and dry weather followed by periods of high humidity and in stored crops damaged by insects.
“The 2015 wheat harvest is just underway now, and I have not seen any reports yet about fusarium, scab or similar conditions,” said Chris Miller, PhD, senior director of research, innovation and quality, Engrain LLC, Manhattan, KS.
Still, bacteria are not in the clear for causing food contamination; the common ones cause most problems. They, too, are plentiful in the environment.
“With salmonella, there are more than 2,000 serotypes in nature,” said Lakshmikantha (Kantha) Channaiah, PhD, director of microbiology, AIB International, Manhattan, KS. “It can survive well in low-water activity or low-moisture environments. It’s a champ of low-moisture foods.
“With Listeria monocytogenes, you have much the same thing,” he continued. “It is everywhere in nature. It can survive and grow under low temperatures — below 40°F, which represents most refrigerator conditions.” The most recent problems encountered in ice cream are an example of listeria surviving under frozen conditions.
“Staphylococcus aureus also can pose issues,” Dr. Channaiah added. “When workers get sick and are not trained in preventative methods, it can be a potential problem in any food environment.”
At risk or not?
The good news? Baked foods and snacks usually don’t make good carriers for microbes.
“Snack foods have very few microbial problems,” Dr. Plimpton said. “Of course, operating with a ‘safety first and foremost’ approach is essential throughout the food industry. Snacks are no exception, but the incidence of such problems in salty snacks is so low as to be almost non-existent.”
SFA’s general counsel, Martin J. Hahn, partner, Hogan Lovells US LLP, Washington, DC, affirmed her statement. “The bottom line is, snack foods are a very safe category of foods given the manufacturing that delivers a kill step and the low water activity of snacks,” he said.
At the time of this spring’s incident with listeria contamination of ice cream, SFA alerted its members to the situation. It noted that the bacteria won’t grow when water activity is 0.92 aW or lower. “Low-moisture products such as potato chips and nuts, for example, are not typically susceptible to Listeria monocytogenes,” the group stated. “It can be found in soil; however, growth of listeria in a plant environment does require wet conditions.”
Baked products are generally trouble-free from a microbial standpoint, largely because the baker’s oven provides an effective kill step.
“With flour, you have a dry product with a really low risk of microbial contamination,” Dr. Miller said. “Pathogens like E. coli and salmonella in flour are rare. These organisms have human or animal origins. When we find them in the finished flour, it’s almost always due to contamination from an outside source.
“The situation a few years ago with E. coli in raw cookie dough is a rare example,” he continued. “In general, wheat, corn, oats or any cereal grain as it comes in from the field and from storage has low incidence of microorganisms.” There are areas during processing that have higher moisture conditions and could typically allow microbial numbers to increase, Dr. Miller explained.
The biggest risks, however, are with mycotoxins produced by the fungi that grow on grains, according to Dr. Miller.
Dr. Channaiah agreed, “For grain-based products, it’s mainly about fungi.”
Grains grow in the open, subject to natural seasonal differences. “Year-to-year variation is not so much a concern with bacteria, but it certainly is with fungi, which are very sensitive to the environment,” Dr. Channaiah said. “In general, cool and wet conditions can foster fusarium and can lead to DON and vomitoxin present in wheat flour. Wet and humid conditions favor aspergillus growth and the presence of aflatoxins.”
Combating microbial problems
For Dr. Miller, who has a background in milling and previously taught milling science courses at Kansas State University in the Department of Grain Science and Industry, control starts at the mill. “Keeping mycotoxins out of the food supply is not so much the baker’s concern as the miller’s,” he said. “The mill has the responsibility to reject contaminated grain supplies; the baker wouldn’t see that risk.”
Testing for the presence of these issues involves separate techniques, and their use by millers depends on the bakery customer’s specs and the application for the flour supplied by the mill. “Obviously, baby food would have zero tolerance,” Dr. Miller noted.
The presence of bacteria is determined by plate counts that measure the number of colony forming units (CFU) of aerobic bacteria present in the flour. “Taking this measurement is common practice,” Dr. Miller observed, “and these bacteria are mostly the normal ‘good’ bacteria living in nature.”
Mycotoxins, however, present a different scenario, he noted. The grain is tested at its receiving point. Strict ppm and ppb limits set by FDA determine whether or not the grain will be accepted. “Some years present more problems than others,” Dr. Miller said. “Some growing seasons produce conditions that make it nearly impossible to find mycotoxin-free grains.”
Well-conceived environmental monitoring programs can mitigate problems, but Dr. Channaiah cautioned, “Having an environmental monitoring program does not make food safe. You have to come up with practical actions, and you have to act in a timely manner once you need a correction.”
As the food industry readies itself for regulations under the Food Safety Modernization Act of 2010 (FSMA), the kill step required by law is a simple concept, but a potential hot potato. The kill step is the point in the process that sterilizes the food, killing any microorganisms present.
The miller and the baker are partners in producing grain-based foods, but their circumstances are different. “The miller does not have a kill step, nor is one required by FSMA because the miller’s product — flour — is an ingredient of a further process and not eaten raw by humans,” Dr. Miller explained. “It is only consumed in finished products, and it is generally accepted in the industry that the baker will perform the kill step.
“The microbial load of a loaf of bread coming out of the oven is close to zero,” he continued. “Most are baked off, killed in the process.”
That said, it’s essential that every food manufacturer — every baker, every snack food maker — have a robust hazard analysis critical control points (HACCP) program, according to Dr. Plimpton. In fact, FSMA rules turn the HACCP discipline into an even stronger protocol: hazard analysis and risk-based preventative controls (HARPC). “These controls start with hazard analysis and move from there through inventoried materials and their contribution to the safety of manufactured foods,” Dr. Plimpton explained.
“And while you have to be able to trust the certificate of analysis (COA) you get from your supplier, you also have to test first and test again,” she added.
Avoiding microbial contamination, Dr. Plimpton noted, involves not only how ingredients are stored and handled but also how foot traffic moves through the plant. “There is no food manufacturer out there that wants microbial problems in the plant,” she said.
Big changes coming
As the food industry struggled in recent months with renewed efforts to address and prevent microbial problems, it also faced imminent changes in the way food safety will be regulated. FDA is under court-ordered deadlines to issue key final FSMA rules in the summer, with the first due out Aug. 30. The rest will emerge during fall 2015 and spring 2016, with implementation dates to kick in during 2016 and 2017.
The supporting law, enacted in the wake of produce contamination episodes, is clear about the need to move food manufacturers from reactive, passive controls to proactive, anticipatory and preventative controls. FDA, too, has been charged with getting out of after-the-fact enforcement and into before-the-fact prevention.
It’s a big assignment. “Overseeing industry compliance with seven new regulations — essentially at the same time — is practically unheard of and has, and will, continue to take a tremendous effort by many in FDA’s foods and feed programs,” said Roberta Wagner, deputy director for regulatory affairs in FDA’s Center for Food Safety and Applied Nutrition, in an interview posted on FDA’s website.
Although a federal mandate, FSMA regulations will have local impact, too. “The states have an important role in FSMA implementation — both in helping educate industry and in conducting inspections on FDA’s behalf,” said Joann Givens, acting regional food and drug director for the Central Region in FDA’s Office of Regulatory Affairs, in the same interview. She and Ms. Wagner are co-leads of the agency’s implementation team steering committee.
Unlike nearly every other regulation written by FDA, FSMA rules take a flexible approach — flexible in how the agency can interpret and enforce them, according Michael R. Taylor, deputy commissioner for foods and veterinary medicine, FDA.
Charles M. Breen, senior regulatory consultant, EAS Consulting Group, Alexandria, VA, explained, “The program will be more flexible — for FDA. FSMA rules are being written so broadly that there will be no one way that every company must comply with the regulation. Rather, there will be many ways. One industry’s means of compliance may likely be different from another industry’s.”
What does that mean, specifically? “For example, a baker making a cream-filled pastry will have different food safety needs than someone making baked chips,” Mr. Breen said. “That’s because the microbiological risks with cream are higher.
“In actual enforcement, we are not sure whether FDA will want to see everyone in a given industry do the same thing,” he added, “however, the flexibility within an industry or industry segment won’t be as broad as the flexibility that FDA has to interpret the regulations.”
“We are hearing concerns that the agency may not have the resources to accomplish the roll-out of FSMA on time,” Mr. Breen said.
Get prepared, stay prepared
News bulletins and targeted communications about webinars, specialized training, inspection services and evaluation programs now bombard food manufacturers as announcement day approaches for FSMA regulations. It’s hard to escape the “be prepared” message.
Every food manufacturer should look at the proposed rules carefully, Mr. Breen advised. “Start with what is different about FSMA. What is a hazard? What is a preventative control? What are the microbiological controls? You have to look at each aspect as it applies to your business and your situation,” he said.
Mr. Breen explained that in baking operations, bake time is an aspect of preventative control of microorganisms. “For some items, the result can be safe foods — processed long enough to be the kill step, the preventative control point — but the food may not be salable. The baked item reaches kill temperature, but that may not be high enough to set the structure,” he said. “You must look at how the rules apply to your situation.”
Validation of kill steps is an essential part of FSMA. “It will be the mantra of FSMA,” Dr. Channaiah predicted. “You have to provide scientific documentary evidence for the kill step, proving it consistenly delivers the desired lethen effect to ensure destruction of pathogeic microorganisms. [In the baking and snack industries], foods pass through a kill step — baking, boiling, roasting, frying — but these stages will need to provide scientific validation of their effectiveness now.”
Data supporting validation — for example, readings of data loggers put through ovens or fryers to record temperature conditions — must be made available to FDA inspectors. “The agency will want to see the actual data,” Mr. Hahn said.
Food processors must keep in mind that food safety and food quality are different. “FDA is concerned about food safety,” Mr. Breen advised, “and food processors are also concerned about food quality.”
FDA has already offered final regulations for two of the seven FSMA priorities. Next up will be Preventative Controls for Human Food.
“Companies need to be prepared,” Dr. Plimpton said. “You will need to have preventative controls in place within the compliance period. Those who have gone through Global Food Safety Initiative programs will be ahead of others who have not.”