I had the chance to chat (by phone) on May 19 with Mike Doyle, regents professors and director of the Center for Food Safety at the University of Georgia, Griffin, Ga.
10:00 a.m. Tom Karst: You have long history with the issue of food safety. How long have been with the University of Georgia?
10:01 a.m. Mike Doyle: I have been here at Georgia almost 20 years, and before that I was at the University of Wisconsin for 11 years.
10:03 a.m. Karst: Did you grow up on a farm? What was your background?
10:03 a.m. Doyle: I spent most of my younger days on a dairy farm in Wisconsin near Madison.
10:04 a.m. Karst: What interested you in the topic of food safety? How did you get steered in that direction?
10:05 a.m. Doyle: When I was at the University of Wisconsin as a student, I become very interested in bacteriology because of some of the courses I took. With my background — having grown up on a farm — I kind of married the two, my interest in bacteriology and food.
10:06 a.m. Karst: Tell me about the Center for Food Safety. How is the center funded to conduct its work? What are some projects the center is involved with?
10:07 a.m. Doyle: The center is funded largely by federal competitive grant monies. I’d say about 90% of the funds that we have at the center come from federal grants. We do get a portion of our funding in unrestricted gifts from the food industry, and it is from diverse (sources).
The projects that we work on are largely focused on developing better ways to detect, control and eliminate microbes along the food chain, from the farm to the table. And we are working on interventions that are effective in mitigating the risks of harmful bacterial contamination, parasites as well as viruses like norovirus.
10:08 a.m. Karst: What is in your inbox? What are you working on right now?
10:09 a.m. Doyle: We are continuing to try to develop effective interventions that can be used on produce and fresh meats. We’ve got one that looks real promising and it has already been licensed by a company that is going to market it in the near future. It’s a wash that works very well on produce as well as on fresh meats. It not only kills salmonella and E. coli but our virologist has just found that it is quite effective on norovirus.
10:10: Karst: This is a wash that would be used in the packing of produce?
10:10 Doyle: It could be used in the field when they harvest lettuce, and it could be used in washing produce and poultry.
10:11 a.m. Karst: With your involvement in the issue of food safety, you have seen a lot of developments over the past 30 years. Is the problem of food safety getting more complex over time?
10:12 a.m, Doyle: There are a lot of challenges that have evolved over the years. Right now the biggest challenge facing the country in food safety are foods coming from other countries where levels of sanitation in producing and processing are not equivalent to what our expectations here are in the U.S.
The most recent outbreak that has been investigated by CDC and the state health departments is salmonella Montevideo in peppers. That’s a prime example. Most of the spices we consume come from other countries, and many of the countries that produce these spices do so under conditions that many of us consider to be insanitary.
10:13 a.m. Karst: That is of the big challenges for FDA, then, in crafting regulations and Congress in their food safety legislation to try to account for imports n a meaningful way?
10:14 a.m. Doyle: It is not just a challenge for the regulatory agencies, it is a challenge for the food industry, because it is the food industry that is responsible for producing safe foods. It is the government’s role in making sure the food industry is living up to its accountability in producing safe food. But the food industry has to insure that the spices are safe if they are going to put them in their product.
10:15 a.m. Karst: Does the concern about imports also span across other food categories, such as fresh produce? In your view, are there variable levels of concerns about different types of food imports?
10:16 Doyle: A lot depends on the country and the commitment of that country in insuring the safety of foods. It is clear that countries like China, where high level authorities in areas of public health and food safety clearly indicate that many companies don’t have a true commitment to insure the safety of foods. They are more economically motivated and we have instances of intentional adulteration for economic gain, the most recent one being adding ground limestone to flour. And melamine – we’re all familiar with that — being added to dairy products and certain other foods. So there are lots of examples of issues like that, but not only that, but many of the foods produced in China can be produced with less than sanitary conditions. Such as how shrimp and tilapia are produce in aquaculture in China where chicken manure or raw pig manure is the source of nutrients for the shrimp or tilapia, and night soil is added untreated to the soil for growing produce. I’m not sure how many people are aware how much produce is coming from China right now. More than 50% of garlic, 60% of apple juice consumed in the U.S. comes from China.
10:19 a.m. Karst Talking about the issue of produce safety I saw you were quoted in a Washington Post article (stating) that bagged salads are inherently more risky (than whole commodities). Is that an accurate quote?
10:20 a.m. Doyle: That’s an accurate quote. I’ve had concerns about (bagged salad) for years. The fresh cut industry —initially, when I was first aware of how bagged salads and bagged lettuce - in particular iceberg lettuce was processed, the process then was that they cut the lettuce heads and they (would) bring the lettuce heads, cooled, to the processing facility, where they were then cored and the outer leaves were removed and further processed.
In the interest of being more cost effective and efficient, the industry went to coring and removing the outer leaves in the field, so what’s left is what we are going to eat. Some companies some years ago were even shredding and bagging in the field, and my understanding is that portion of the process doesn’t occur anymore in the field. But still it is a widespread practice to core and remove the outer leaves in the field.
The outer leaves are where you are likely to find the contamination present. Secondly, the cutting of the lettuce – the way it is harvested - can lead to contamination.
I had concerns about this and it has been validated in the lab. My concern is that if that knife hits the ground and if the soil is contaminated with bacteria like salmonella or E. coli 0157:H7, when that knife cuts the lettuce, there will be contamination introduced. Then when the same utensil is turned around to core the lettuce, which will force the contamination into the lettuce, when the core is removed. What happens, when the core is removed is the lettuce begins to form latex to keep nutrition bleeding out, it forms a clot like we do when we get a cut.
The lettuce head will form this white latex and if the bacteria should be present, when the core is removed, it will be trapped. So you are not going to wash the bacteria away.
So I have concerns about this. Basically what the fresh cut industry has done is they have brought the processing of lettuce to the field
And thinking aloud, would FDA allow a processing facility to have a dirt floor like that? I don’t think it is under good manufacturing practices.
10:23 a.m. Karst: Will there be compelling reasons for the industry to rethink how bagged salad is processed?
10:23 a.m. Doyle: Do I think it will change? I think it will take an act of the government to make that change. It is a matter of economics.
It costs money to take the waste that is brought to the processing plant back to the field.
10:23: Karst: There is a lot of talk about the value of sampling product before harvest. What is the best preventive control that could apply to improve food safety and not just add costs to the process?
10:24 a.m. Doyle: I’ve seen how some companies go about taking samples the field and I’m not convinced that type of sampling g is going to be very effective. It seems you get much more accurate results if you test materials that have been harvested before it is further processed.
10:24 a.m. Karst: What about irradiation? Is that the silver bullet that could solve these issues of contamination in bagged salad?
10:25 a.m. Doyle: It could be, as long as it provides good sensory characteristics and as long as it doesn’t adversely affect the quality of the product.
10:26 a.m. Karst: Do you see that in the next 10 years? What kind of a timeline do you expect before irradiation may be a part of the picture?
10:27: Doyle: It is not a matter of whether the product is safe or not safe. I mean the FDA an others in the know have evaluated that and already approved the process. From my perspective it is not a safety consideration, the consideration is will the consumer buy it if it has a label on it that says it has been irradiated? My understanding of consumer preferences is that consumers who buy fresh fruits and vegetables largely don’t want those types of product irradiated. I think it is going to be a matter of convincing consumers that the irradiated product is better from a food safety perspective than the non-irradiated product.