Episode 31: University of Arkansas Department of Food Science

This week on Water in Food is Dr. Jennifer Acuff from the University of Arkansas System Division of Agriculture. She's also an assistant professor of food microbiology and safety in the department of food science at Dale Bumpers College.

Currently, her focus is microbial contamination in low-moisture foods, including products like spices, nuts, dried fruits, and powders. Her goal is to expand the body of knowledge about pathogen contamination in low-moisture foods and conduct applied research that provides real solutions. Then, she will also identify ways to present food safety training to help small food processors in order to comply with the Food Safety Modernization Act. Hear what Dr. Acuff has to say on Water in Food.


Zachary Cartwright: I'm Zachary Cartwright. This is Water In Food. This week my guest on Water In Food is Dr. Jennifer Acuff, who is part of the University of Arkansas System, Division of Agriculture. She's also an assistant professor of food microbiology and safety in the Department of Food Science at Dale Bumpers College.
Zachary Cartwright: Now, currently, she's focusing on microbial contamination and low moisture foods, including products like spices, nuts, dried fruits, and also powder. Her goal is to expand the body of knowledge about pathogen contamination in low moisture foods, and also to conduct applied research that provides real solutions.
Zachary Cartwright: Then she will also identify ways to present food safety training to help small food processors in order to comply with the Food Safety Modernization Act here what Dr. Jennifer Acuff has to say on this episode of Water In Food.
Zachary Cartwright: All right, well, hi Jennifer. Welcome to the Water In Food Podcast. Thanks for being here today.
Jennifer Acuff: Thank you so much for having me.
Zachary Cartwright: Can you first start off by telling me a little bit about your role at the University of.
Jennifer Acuff: Yeah. So, my job here is in Fayetteville, Arkansas, and it's a three way appointment with the majority of that being research and teaching and extension. So it's kind of split almost down the middle, but the majority of it would be on the research and extension side.
Jennifer Acuff: So I primarily focus on the safety of low water activity foods. And then I just try to add a lot of extension components as much as possible to those research projects, and then do a bit of outreach and training as well. So that's a core mission because we're a land grant university, so we're always trying to find ways to return our research to our communities.
Zachary Cartwright: And you're also teaching at Dale Bumpers College, is that correct? And if so, what? What classes are you teaching?
Jennifer Acuff: Yeah. So I get to teach the food microbiology lecture and lab courses, and I also teach two online classes for our online master's program in food safety. And those focus on applied food microbiology for the industry as well as food biosecurity.
Zachary Cartwright: And I, I heard that this year you were awarded huge grant. Congratulations. This $200,000 grant from the US Department of Agricultural Natural Institute of Food and Agriculture. And I was wondering if you could maybe just for now, give me a little bit of an overview of how you're planning on using these funds.
Jennifer Acuff: Yeah, sure. Thank you so much. We're really excited. It is a big grant for me, being relatively new to the university, but it is technically a seed grant. So that means the U S D A is investing a little bit of money. It's big for me, but you. Relatively small for their, large funders.
Jennifer Acuff: . . But it's a substantial amount that's gonna help my program really get some foundational information and data that's going to hopefully spur some larger multidisciplinary and very collaborative grants. For U S D A in the future, that's the goal. So we're investigating how well foodborne pathogens like salmonella or sugar toin producing e coli can survive in low moisture food environments.
Jennifer Acuff: So we're inoculating small pieces of stainless steel coupons just the little kind of slivers, sub cutts of those with pathogens and then powdered foods at varying ratios. To allow the substances to dry and then store them at different temperatures and relative humidity levels. So in these experiments, we're checking the impacts of specific amounts of water and storage conditions on what we're calling low moisture food persistent bacterial populations.
Jennifer Acuff: So we abbreviated that with lmf. PPPs. It's a. Bit of a mouthful, . So we're also going to look at how different types of foods or nutrients can impact the survival and what might happen to these lmf PPPs when moisture is reintroduced. So two big questions in the low moisture food industry. That scientists also have are how foodborne pathogens become house bugs in these low moisture food processing environments.
Jennifer Acuff: And then how do we get rid of them? So our research is really just trying to further our understanding of the contamination and persistent scenarios in a low moisture food processing environment so that we can develop. Better strategies in the future for cleaning, sanitation, and even hygienic equipment design.
Zachary Cartwright: And where does your interest in low moisture foods come from? Is, is this something that you're personally interested in, something that you maybe studied in, in graduate school? Where, Where is this coming from?
Jennifer Acuff: Yeah. So I did get introduced to low moisture food safety research when I was in school.
Jennifer Acuff: I did an internship one summer and worked on a project that was related to poultry powders that you might use in broths or reconstitute some other way. And then throughout. My graduate school at Kansas State University and then at Virginia Tech. I got to work on projects as well that had low moisture food components and it was the focus of my PhD dissertation research.
Jennifer Acuff: And also I really just, I like eating low moisture foods, so they're not often suspected as risky, but outbreaks and recalls aren't. Necessarily uncommon anymore. And so there've been quite a few high profile outbreaks even recently. So, a lot of times these are foods that we're feeding to our kids.
Jennifer Acuff: They're convenience foods. They're things that have long shelf lives. And so we really are expecting them to be perfectly safe. And consumers are very disappointed when they learn that that may not always be true. So that's why I'm personally interested. And then professionally, it's just grown as the research kind of pushes me in those areas.
Zachary Cartwright: And I understand you've had an interest in food safety for a a long time. Is, is that correct? When did you first start to get into to food science and food safety? Maybe even before you, you went to school?
Jennifer Acuff: Yeah. So I've been really interested in food safety for a very long time. My dad is actually a food microbiologist and worked for many years at Texas a m University, and he's retired now, but he still consults.
Jennifer Acuff: And so I was introduced to food microbiology at a very young age. He would Bring me to his classes and his labs. And so that's where I started getting experience in that kind of terminology and in that space. So I've always been really interested in microbiology and and I knew that's where I wanted to be.
Jennifer Acuff: And then in college I decided I wanted to push. More into the food micro side of things. So we all have to eat food and it's a very personal thing and I found that over the years, having some of the knowledge that I did having, a parent that was in that space, it gave me a really interesting viewpoint and vantage point from seeing how consumers receive information about food safety.
Jennifer Acuff: And it's made me really passionate about trying to Trying to disseminate that knowledge as much as possible. I think it's important that consumers get all of the information they possibly can so that they can make the best decisions that they're able to. And so I, I like to be a part of that.
Zachary Cartwright: And you mentioned that there's been several recalls definitely recently. And I, I was wondering if you could maybe touch on maybe the companies, or at least the product types that you have seen recalls in recently in low moisture foods.
Jennifer Acuff: Yeah, so there are some particularly high profile ones. Things like I, I would say nuts, especially nuts and chocolate were some of the earliest outbreaks that were noticed. And some, some rules came out of some of those outbreaks, especially with the nuts and almonds. But I would say the really big ones that people notice now are things like peanut butter. So a number of years ago we had a big peanut butter outbreak, and We've also had infant formula recently, and then the ongoing one that we have is flour.
Jennifer Acuff: So flour's a, a low water activity, food. And a lot of people don't realize that it's raw, but now you can find on the package that says this is a raw product, but that wasn't always the case. Hmm. And so there are, it's It's tricky because all low water activity, food outbreaks, they have some similarities, but they also have huge differences because we're talking about, this has got to be.
Jennifer Acuff: Probably one of the most varied commodity groups, right? There are so many things that can fit in this category. They're all grown and processed and made differently. And so there's not one thing that is a consistent problem, There are some unifying features. Things like hygiene and sanitation.
Jennifer Acuff: House bugs, like I already mentioned. If contamination happens, it's very difficult to get rid of them from that environment. And so, I think all of these outbreaks are similar in that they have, they have a contamination issue and then the pathogens survive for a very long time. And then because of the nature of low water activity foods and what they're used for, they're oftentimes sent into many other products.
Jennifer Acuff: So things like flour gonna be added to baking mixes. Things like peanuts and peanut products are gonna be added to granola bars and other food food items. Right. And. I think we just see that when a recall or an outbreak happens with a low water activity, food, it's so often very far reaching .
Jennifer Acuff: Um, When it's these kinds of ingredients.
Zachary Cartwright: And when these recalls happen, do you have any sense of, of what it costs a company to, to fix it? It?
Jennifer Acuff: Well, it totally depends. Sure, it really depends on what their issue is. I know that this recent situation with the infant formula is incredibly costly. And I don't, I definitely don't know the numbers there yet. It's just, It hasn't we haven't had that kind of analysis, but it can cost a company hundreds of thousands depending on how bad the outbreak is, If there's an outbreak involved, recalls will cost a certain amount. Outbreaks cost exponentially more.
Jennifer Acuff: Cuz you have, have other aspects, other litigation and things like that, but it could be up to millions of dollars. And it's astronomical the consequences of an outbreak. And I think, With the Peanut Corporation of America, they even were convicted, you know? . So there's a lot of non monetized costs as well with outbreaks and recalls.
Zachary Cartwright: Right. And we even had, we saw a recent article, And maybe we can add the link to this, but I saw somewhere that the average recall is somewhere between seven and and 8 billion. And of course, it depends on a lot of different factors, but I think the bottom line here is that it, it does cost a lot.
Zachary Cartwright: And even though pathogens aren't as present in low moisture foods, what, what it sounds like you're saying is when they're there, it's gonna be a really unique case, and then it is really difficult to get rid of them .
Jennifer Acuff: Yeah, and it's really nuanced because the way that a recall happens is it's, it depends, but sometimes it has to do with when was the last time you had some kind of cleaning and a, and a negative pathogen test? And so for a low moisture food, they might be processing for a long time before they're, having a total clean break. And so sometimes that can mean your recall is. Is just humongous.
Jennifer Acuff: And there's that's very different than like a produce packing house where they're having clean breaks every day. And so you're, you're able to kind of isolate things a little bit differently. So that's a big challenge for the low moisture food industry especially.
Zachary Cartwright: I've noticed in a lot of your press releases or things covering this grant that you just won, the term low moisture will be used a lot and not so much water activity. And I'm wondering if, if that is a decision that you've made or why you use the term moisture instead of water activity and some of these things that are released.
Jennifer Acuff: Yeah, well, it really just depends on who I'm talking to and or who I'm talking for. So obviously you guys are very aware of water activity but I assume some of your audience is still becoming familiar with that term and what it means.
Jennifer Acuff: So, low moisture is just, I have found a more accessible term to the public. When I say low water activity, I usually have to then go into the full-fledged definition of what that means and why it's important. And so of course there. Pretty technical differences between moisture and water activity.
Jennifer Acuff: Pretty big ones, as but the general public is just not usually familiar with that term. And so, it's a little easier to, to get people kind of on the same page as you when you start talking about low moisture and then you can bridge the gap into water activity. And I said that a lot too, even in my own position, whether I'm talking to maybe the cannabis industry or pharmaceutical industry or something, they will tend to, recognize the term low moisture.
Jennifer Acuff: But I think once you have the chance to really sit down and describe water activity, then it, it starts to, to make some sense. Yeah.
Zachary Cartwright: How does using water activity strengthen your research?
Jennifer Acuff: Well, water activity gives you a really good read into what amount of water is available, obviously. And not currently bound by something else. And so it tells us how much is available for bacteria to use. So that's a good indicator of whether or not you can expect growth of bacteria. . So that's primarily what we use it for. Water to me can be used for a lot of other things, but really it's our, it's kind of key measurement when we're trying to target certain levels. We've seen an increase in thermal resistance from bacteria as you decrease the water activity. And so, whenever you're looking through publications in this field you're always gonna be asking, Okay, so that was the thermal line activation rate, but what was the water activity?
Jennifer Acuff: Because that's, that's one of the key measurements now that we use to compare different commodities. So it really does have a huge impact, the water activity on bacteria and how they survive for how long and how they die after they've been treated with something. And so we like to know what that measurement is to help correlate some of these some of these trends.
Zachary Cartwright: I also wanted to touch on your experimental design a little bit. It looks like you'll be using what's called surrogate bacteria. Basically bacteria that you can introduce into a company's production line to verify detection and in activation systems And make sure that they're working correctly. If you're going to use this approach, how can a company that you're working with, how can they be confident that this bacteria isn't going to cause problems down the.
Jennifer Acuff: Yeah, that's a good question. So, there's a couple of criteria that bacteria would have to meet to be called a surrogate. And one of them is that it is non pathogenic. So, if somebody is using the word surrogate, then the assumption is, It has been determined that it's non pathogenic. So sometimes that can just mean it to BSL 1 it's harmless to humans. It's maybe not even a human pathogen. So there's a couple of reasons that a bacteria might not be harmful or a threat to human health.
Jennifer Acuff: It could be that it's an, a virulent strain of something. So you have to, you have to follow up. I would never, if, if I were a company, I would never allow somebody to come in saying they have a surrogate without at least verifying that the research has been done to show. This is the good option and it really is a true surrogate; it's harmless.
Jennifer Acuff: But but yeah, that's one of the main criteria. So I don't know if that fully answered your question.
Zachary Cartwright: I think it does. And I just think that that approach is really interesting and I'd be interested to see how companies handle this And how you explain it to them. And also the results that you get from this I think will be really helpful if you're, bacteria right there in their production line. So I, I look forward to see how that turns out.
Jennifer Acuff: Yeah. I'm looking forward to it. It can be. I, I think a lot of people in the food industry are very familiar with surrogates now, maybe 20, 30 years ago that not as many were familiar with it. So it got a lot of concern. Sure. And you said you wanted to bring in a live bacteria,but luckily people are starting to see how helpful that research can be and how, they really are harmless bacteria.
Jennifer Acuff: You always have to follow up.
Zachary Cartwright: And then I also understand that part of the grant funding that you're receiving, it's going to be used to figure out some of the best ways to present food safety training to small food processors that have to comply with the Food Safety Modernization Act. How do food, how do small food processors currently receive this type of training, and what are some of the improvements that you're already planning on?
Jennifer Acuff: Well, every plant and every processor is going to give their training a little bit differently. So it, they're, for the Food Safety Modernization Act, they need to have a a qualified, a preventive controls qualified individual who can disseminate the information required in their. In their preventive controls plan and food safety analysis.
Jennifer Acuff: So, every plant is gonna do it a little bit differently. My goal though is to really get into the good manufacturing practices or GMPs and plant design, because you could give everybody all of the same, the same exact training, the same textbook, everything. And they'll go back to their plant they have to figure out how to apply it. And every plant is totally different. Their design, the personnel, the product that they're making. And so there's not one single set of training that is gonna make perfect sense to every group, right? It's gonna always be even within a company. Their plants are going to be different, right?
Jennifer Acuff: They didn't build all of their plants at the exact same moment, right? They, they buy And trade and sell and they improve, and things don't always look the same from plant to plant. So, each with that uniqueness, I think we need to have unique, good manufacturing practices and unique plant designs.
Jennifer Acuff: So what I think is that these programs really need to have some customization and have people willing to go into the plants And train their employees in, in that applied environment, in their actual real environment. If the employees understand why we're concerned about even a little bit of moisture, condensation on the wall or on the equipment, if they understand why we're concerned about that, they're more likely to see it and actually report it rather than just fix it and then move on. Or maybe not even fix it and just move on. Right. So, I think that's what I'm hoping to do is to actually information and trainings that actually apply to those processors no matter you know, which plant they're in. They have a way to make those connecting lines and train their employees with a lot of baseline knowledge and not just check these boxes cuz that's, they're
Jennifer Acuff: Pathogens find a way to evade all of the checklists. They just do.
Zachary Cartwright: And then finally, you, you're among a really small group of individuals in academics who study or use water activity in their research. And I was just wondering if you could talk about why you enjoy being in academics. Why, why have you decided to, to stay there?
Jennifer Acuff: Well, luckily that small number is growing a lot. So I mean, part of it is that it's it's that now a funding priority among some agencies, and so people are like,"Well, I can, I can jump into that." And so luckily our numbers are growing, so that means that there's a lot of opportunities for really neat collaborations.
Jennifer Acuff: That's primarily why I stayed in academia at this point is I really love to work with students. I love teaching and I like this extension portion of my job as well. And so it's just very fun for me to get, to share knowledge give and receive as well. But I really like being able to work with a wide variety of groups because I'm in academia, so I get to work with industry members. Individuals from the regulatory agencies, and then I get to bring students along with that. And they're eager to learn and eager to try and they're motivated.
Jennifer Acuff: And that's just, it's a lot of fun. it's constantly new. It's a little bit crazy. We don't always know what we're doing from day to day but it's just a lot of variety and it's a lot of fun.
Zachary Cartwright: And then finally, what is the timeline for this current project that we've been talking about and when can we expect you to come back on the show to, to give us an update?
Jennifer Acuff: Well, hopefully, hopefully anytime you ask me to come, I'll have something to update, though it might be small, small benchmarks. But this grant is going to wrap up in December of 2023. But I'm certainly hoping that we're going to start being able to compile some of the results that we're getting and.
Jennifer Acuff: Working out some presentations and publications as we go. we expect several different things to come out of this grant and I'm hoping that they don't all come out just at the end. I think we'll be able to kind of pace ourselves. So hopefully in the next six-ish, six to nine months, we'll have some new things to talk about.
Zachary Cartwright: Well, great. Well, thank you so much, Jennifer. we really appreciate your time. I, I am looking forward to an. And this is, one of my favorite part of my jobs is getting connect to connect with clients, but also with, people in the university system And seeing and understanding what the research is.
Zachary Cartwright: So I'm sure we will invite you back at at some point. But thanks again for coming on today.
Jennifer Acuff: Thank you. This was great to talk about this. We're so excited to talk about the research we have going, so I really appreciate the time.
Zachary Cartwright: I'm Zachary Cartwright. This is water and. Find this podcast on Apple, iTunes, Spotify, or wherever you listen to podcasts.

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