 Welcome, everyone. My name is Julie Garden Robinson and I'm your host for today's field of fork webinar. This is brought to you by North Dakota State University Extension. And this is the seventh year that we've done the series and are really glad you joined us today. The next slide shows our upcoming webinars. I hope you plan to join us to learn more about attracting pollinators to your garden, which is a really important topic. That's by Janet Kanotl. She's an entomologist here at NDSU. And then on April 13th, we'll have Landa Nwadaki and Anna Barr, and they're from Kansas State and Missouri and South Dakota, respectively. And they'll be talking about farm to school getting started and best practices. The next slide shows our webinar controls, because we have a large number of participants, we invite you to post your comments in the chat. And we're going to practice using and finding the chat box. So click to open the chat. And if you've been on these before you know what to do, type your city and state in the chat. The next slide provides an acknowledgement. As you work on typing in your city and state, I have a special request. This program is sponsored in part with grant funding from USDA's Agricultural Marketing Service. And I will ask all of you to complete a short online survey that will be emailed right after today's webinar. And thank you, I have prizes for the lucky winners and as more than one winner every week. So be sure to put your complete address on the follow up form, and don't forget to include your city, state and your zip code. Sometimes I have a hard time tracking down my winners and I have to Google them and try to figure out their address. Welcome to today's webinar and I'm very pleased to introduce today's speaker. This is his first time speaking with our field to fork group. Byron Chavez is an assistant professor and food safety extension specialist in the Department of Food Science and Technology at the University of Nebraska Lincoln. His research focuses on designing evaluating and optimizing antimicrobial interventions for foods of animal origin, and also on characterizing foodborne pathogen growth under simulated product and process conditions. His extension or outreach program focuses on providing training and technical assistance to food manufacturers in food safety, sanitation and regulatory compliance. He is the USDA FSIS State HACCP coordinator for Nebraska, working very closely with small and very small meat processors, as well as he serves as a Nebraska lead for the North Central Region FISMA Center, where he provides assistance on environmental monitoring, interpretation of microbiological data and improving good manufacturing practices. Byron holds a PhD in food safety from Texas Tech University and has been on the faculty at UNL for over four years. So thank you for being with us and it's all yours. Thanks. Thanks, Julie, can you hear me okay. Yes. Excellent. So thank you so much for the invitation to talk to you and your audience today I am very excited to be here and I'm very impressed with this series of talks and conversations of the field to to table. So today we're going to talk a little bit about developing safe food products and really what I'm going to cover is very general so I encourage everybody that has questions to please reach out to me with, you know, with with questions about what I'm going to talk about this is just going to be very general for the purpose of time. What I want to cover is, you know, the goals that I have is for the audience to understand a little bit about what are the intrinsic and extrinsic factors that affect microbial growth in foods, and how those factors interact with one another to either control microbial growth or to control microbial growth. And of course this is important because we know that so many people get food poisoned every year right so we have epidemiological estimates that say that maybe one in every six people in the United States get a foodborne illness every every year. And of course we think that that is preventable right we want to prevent foods from becoming contaminated. And so so we work under the premise that foodborne illness is entirely I'm sure that lots of people in the audience have had food poisoned right I've had I've been food poisoned that I can that I can recall maybe three times in the last 15 years, and I know that that that I know the cause of all of those of all of those instances was one was Salmonella the other was Giardia, and the other was Clostridium perfringence and so, so I know that it's very uncomfortable and so we want to prevent this from happening. So when we think about the microbiology, the microbiology of food processing, we know that microbes in foods can be good, can be bad or can be really ugly right and so the good ones are the ones that we use for bioprocessing and fermentations and to develop flavors and textures in foods. The ones that are bad are really the spoilage ones right so those spoilage ones will reduce the shelf life of the product but are not really going to cause illness in general. But then we have the really ugly ones and those are the ones that cause illness in humans. And so those are the ones that we really, really want to control for safety purposes, foods are very complex as most of you probably know. And so there's a lot of different microbes that interact in food in food products at any given time, especially when the product is wrong when we have a lot of different cultural commodities and highly perishable food products. So the microbial profile will be determined by a number of different properties including factors that belong exclusively to the food product as we'll talk in a little bit, as well as temperature and relative humidity, the gaseous atmosphere around the product and many others. And of course as you guys know, microbes can be introduced at any point during food production, right so either on the field or in food service during food preparation during transportation. And so the fragility of the food supply in terms of microbial contamination is actually very high right we can incorporate microbes at any point. So this is what I was telling you a little bit about before microbial growth in food it's determined by many factors. The ones that are intrinsic to the food products so the chemical composition the level of acidity, the amount of moisture that the food product has available for microbial growth is what we call intrinsic factors. And those are the ones that I'm going to be talking about mostly today. When we think about conditions of the packaging and storage environment that will be extrinsic factors so things that we can control externally such as temperature, the atmosphere, basically the amount of oxygen that it's surrounding the food product and the relative humidity. And then there's other factors that we're not going to discuss today but are related to the physiology of the microbes right so how those microbes are behaving in foods and what are the interventions that we apply to control for those microbes. Okay, so just a little bit of background about how microbes grow in food so when we think about microbial growth. One thing that I really want to to make very clear it's that not every microbe can actually grow in or on food products. So when we think about bacteria in filamentous yeast and malts. So things that cause illness or that may be cause spoilage those microbes can multiply in foods. But when we think about viruses and parasites those types of microbes don't multiply. So they actually need to be inside of a host to be able to multiply. So whatever amount of parasites or viruses we get on a surface or on a food product, that is what it is right so those are able to cause illness but are not going to multiply in foods or proliferate in foods. But for the ones that do multiply let's think about bacteria as the most common ones. When we think about bacteria there are different segments or different stages that they go through. And the one that it's labeled number two the log phase or exponential growth of growth of phase is the one that we really want to prevent. We want the microbes to prevent actively multiplying because they are going to increase in size. And so, in order for us to do this well we need or in order for microbes to do this to grow they need a number of different things they need nutrients. They need a certain level of acidity and moisture, they also require a specific temperature and level of oxygen, but most importantly they need time. Right and so when we think about time as a factor for microbial growth, really that that leads us to this thing called the temperature danger zone. And when we think about danger zone, we've always been told well you shouldn't keep foods in the temperature danger zone and roughly defined that is 40 to 140 degrees Fahrenheit. And this temperature danger zone is the temperature that will allow microbes to proliferate quickly right so the growth rate increases basically they reproduce faster. And the doubling time decreases and the doubling time is the amount that takes the entire population to double in size. So microbes can actually divide very quickly, and they divide exponentially so two cells become four for two cells become 1616 etc. So they divide multiply very very quickly. So, let me see what I was going to say here so when we think about temperature abuse right when we think about developing products or keeping the products that we already have save from a temperature perspective, we think about temperature risk, which is the temperature time combination that allows growth of pathogenic organisms in the food matrix and so we want to prevent this. And this is why we always insist that people keep foods either refrigerated, or hot, right it's either hot or cold. And we can now assign a value to that right so we want to keep them cold that it's under 40 degrees, and if we want to keep them hot that is over 140 degrees. So many factors as I said before influence microbial growth and if you are thinking about either developing a product right for maybe entrepreneurship, or maybe you're thinking of a cottage food, or maybe you already have a product that you want to put in the market but you are modifying some of the ingredients and some of the conditions of processing. We want to think about multiple factors and one of those factors is the pH and the pH is an indirect measurement of the acidity of a food product or of a solution or of anything. pH scale goes from zero to 14, and it's a little weird but the lower the value so closer to zero that is acidic and closer to 14 that is alkaline or basic. When we are around seven that will be neutral pH so around seven is the pH of pure water at room temperature. And so when we think about classifying foods based on pH there are really three broad categories the first one is acid foods that have a natural pH of under 4.6 when we measure that on equilibrium that there's acidified foods that have a pH of under 4.6 and a water activity above 0.85 and we'll define but that water activity is in a second, and then we have low acid foods that have a pH above 4.6 and a water activity 0.85 and so this is important because when we think about acid foods those are naturally acidic. When we think about acidified foods those may be foods that we add acid or we mix with ingredients that are already acidic to bring the pH to a much lower value right so you guys can see that 4.6 is kind of far from seven right so it's kind of far from that equal of that neutral pH. And so this is what we would call acid foods or acidified foods and of course if it has a pH of over 4.6 and it's closer to neutral that's what we call low acid foods so it has a low acid level and therefore it has a higher pH. Now this value 4.6 is not completely random right so when we think about making food products or creating recipes and we rely on the acidity of the product, then we use this indirect measure of measurement of acidity the pH and that is not completely random. pH 4.6 is the cutoff value for the growth of clostridium botulinum. You guys may have heard about clostridium botulinum as one of the very dangerous foodworm pathogen that creates a toxic toxin that it's extremely potent and it's one of the most toxic chemicals known to humans. And so we want to prevent this from happening because of the public health consequences. So that cutoff value is 4.6. Now when we think about microbial growth based on pH of course microbes have pH values that they like the most and not all of the microbes grow at the same pH values. There is a minimum, an optimum and a maximum pH value. Now some of them you guys can see that 4.6 is not a magic value right 4.6 is a value that stops the growth of clostridium botulinum, but there are other microbes that could potentially survive and even grow very slowly at pH under 4.6. And so the example that I have here is carrot juice versus orange juice, and we know that carrot juice has a pH closer to six, right so around six so it's closer to neutrality, whereas the pH of orange juice is about or around 3.5. Right so that is a food matrix that is inherently more protected against microbial growth because the pH or the pH is lower and therefore the acidity is potentially higher. And Julie I see questions in the chat and do you want me to take a look at this as we go or towards the end. I will pose them to you at the end of your talk. Okay sounds great. So then when we think about acidity right when we think about designing a product based on the core controlling microbial growth in a food product that we are designing or a recipe that we are designing based on acidity, the pH is that best indicator for microbial growth. There is a regulation that it's called the juice has up so the hazard analysis and critical control points for juice processors and this is an FDA regulation. And the reason why this regulation exists is because about, I don't know 30 years ago, the scientific community used to think that most pathogens were controlled by low pH, even if the food product was not pasteurized but now we know that that is not true. We know that there are pathogens such as shigatoxygenic E. coli and certain types of salmonella and certain types of listeria monocytogen is that are actually able to grow and survive under pH 4.6. And so now because of this regulation, all manufactured juices have to be pasteurized, whether that is through a thermal or non thermal treatment. But then that takes us to another significant factor when we think about microbial growth in foods right so as I told you before it's a little complicated there's so many things that interact to determine microbial growth, but this one is water activity and water activity is the available water for chemical and somatic and biochemical reactions. The scale goes from zero to one where one is the water activity of water at room temperature in equilibrium and bacteria require really high values of water activity basically they require the water to be really available for microbial and somatic reactions etc. But fungi can tolerate much lower water activities and that is the reason why we see that dry products to think about bread, when they spoil, it's typically not bacteria right it's typically fungi, yeast and molds, the ones that are actually able to grow in those conditions and produce spoilage, because the water activity is low enough that it's actually controlling bacterial growth. And so that takes us to the point that growth of microbes is different than surviving right so a micro can actually survive in a in a low water activity without being actively dividing and growth is different for growth we actually need optimal conditions. And just like with water or just like with pH there are values of water activity that are minimum optimum and maximum for bacteria and other microbes to grow. And so this we also take into consideration because most microbes require a high level of water activity so we reduce the amount of water that it's available for microbial growth, then that product is potentially safer, although we'll see that it that is not. A straightforward as it sounds in a second. When we think about reducing the water activity of the food product just as when we think about reducing the pH of the food product to control microbial growth. There's many things that we can do right so I didn't mention this when we were talking about pH but if you produce a fermented food product right so that fermentation process with lead to a significantly higher pH than the original value and that acidity that it's been produced and those assets and all of those chemicals that are being naturally produced by the food product or by the microbes in the product are going to reduce the pH. If you pickle something right so you add a certain level of acidity or a chemical substance that it's acid enough that it's going to bring the pH to equilibrium below 4.6 and so we use things like fermentation and pickling and other types of acidification to control microbial growth. We can do the same to reduce the water activity when we are thinking of designing a food product that we can of course dehydrate we can evaporate we can extrude we can freeze a food product and all of those things. Excuse me all of those things will reduce the water activity of the food product basically meaning that there's not enough water available for microbes to grow. We can also change the product formulation and this is one of the most common ones when we are thinking about things like cottage foods or, you know, small businesses that are developing products so entrepreneurship, we use formulation. And for that formulation we can add salts of different kinds we can add sugar which is one of the most common to reduce the amount of water that it's available for foods and make those foods a little more stable against microbial microbial growth. There is a term that you guys may see in the literature or in popular media. It's called a low moisture foods and those low moisture foods in general by definition are foods that have a water activity below for below 0.7. And that is important because those low moisture foods tend to be a little more stable when they are in shelves. Okay, so thinking about these two things this these two combinations of water activity and pH to intrinsic factors that truly have a great influence on determine what is the kind of microbial contamination that we are going to see in food products. I said before that dry foods or low moisture foods tend to be a little more stable right shelf stable but they are not inherently safe. We know for example that there are microbes that are that can easily survive in foods that have very low water activity. You guys might have seen in the news recently there was contamination of powder infant formula and powder infant formula of course is a food product that it's designed for a very high risk population of course infants and babies. So we know that the low water activity help us control microbial growth but it doesn't make foods inherently safe. Right, so the example that we have here is a raw meat product versus a process meat product so in this case some kind of steak versus a, let's say beef jerky. Right, so the water activity of the product is much lower the the process food product has a water activity of point around 0.86 and the water activity of the raw meat product it's about 0.99. So, microbes and the microbial ecology is going to change right so now the microbes that we really care about when we have a dry meat product like in this case would be something like Staphylococcus aureus we're not that concerned about Salmonella and we're not that concerned about Listeria monocycloginous but Staphylococcus aureus it's one of those microbes that can actually grow and produce toxin at a significantly lower value of water activity compared to other microbes. And so we know that even though these products are more stable that these products are not inherently safe right doesn't mean that they are safe think about flour right so wheat flour it's one of those things so that we used to think wow it's so dry the water activity is so low. No, now we know that sugar toxin producing E. coli can be present in that product and survive and make people sick. Think about shredded dehydrated coconut we see Salmonella in those products and of course think about powder infant formula where we see Chrono Bacter Sacca Sacchi I in those products. So, it's a factor to control microbial growth, but it doesn't make it inherently safe just as pH. Intrinsic factor that I'm going to mention to mention is biological structures, and this is also extremely important because structures can prevent entry and growth of pathogens. Think about the shell of nuts and the skin of fruits and the egg cuticle and shell and the membranes and once we remove those things and of course we will be compromising the physical barriers and increasing the probability of microbial contamination. That is the reason as you can see in the picture we compare fresh cut melons and cantaloupes to the whole fruit right so fresh pet product produce is a high risk commodity. And the reason for that is because we don't have those physical protections that we used to have when the product was intact right so so we know of course from a microbiological point of view point of view that fresh cut produce is actually one of the risk is things right because microbes can easily contaminate a product is ready to eat. If the product is temperature abuse, then the microbes will grow very very quickly. And so, besides the intrinsic factors that we need to consider when we are designing a food product and thinking about a recipe and thinking about the consistency and and how stable we want this product to be. Of course we consider pH and water activity of the food product, but we also have to think about external things that we can change. And one of those things is temperature. Most microbes that cause illness will grow at moderate temperatures and that it would be room temperature right so anywhere in the 70 to 80 degrees Fahrenheit, let's say, so that is a really good comfortable temperature for microbes to grow. There are a few microbes however that are able to cause illness, and they are also able to grow at refrigeration temperatures, basically under 41 degrees Fahrenheit. Those microbes of course need to be taken care of because lots of food production is conducted or happens under refrigerate under refrigeration, because it's a really good way to delay the growth of microbes. But some pathogenic organisms can actually grow in refrigeration, and we need to take care of those and so there are specific programs such as environmental monitoring and different temperature controls that we use for these microbes. This one the next one about freezing is really important and I and I hear this all the time from people that they froze the product and so now the product is safe. So we need to be really careful about this because killing or freezing doesn't kill most bacteria. So most bacteria are actually resistant to freezing. A proportion of the microbes are going to die, of course, but once you throw out that product once the product is defrosted, then those microbes can actually recover. Now freezing, deep freezing, it's a really good way to kill parasites. And so if you handle any products such as pork, right, so if you have pork primals or sub primals, right, so if you're handling meat, then freezing is a really good way to kill parasites such as or if you're handling any kind of seafood, I don't anticipate that that just like in Nebraska that you guys are handling a lot of seafood in North Dakota, but who knows right and so freezing is a really good way to kill parasites in seafood. But we don't typically use freezing as a step to control pathogenic bacteria. Now we can reduce the rate at which microbes grow and multiply and of course we use refrigeration and cooling and chilling and freezing to reduce the speed at which they multiply and make the foods a little more stable. And we can also use the other spectrum of the other side of the spectrum of temperature, which will be a thermal treatment. So we can pasteurize we can cook we can can or retort we can we can bake all of those things will help us control microbial growth. So now you guys can see that this, there's so many factors that influence microbial growth and they don't act in isolation right they all interact with each other, as we will see in a second. And I believe the last factor I'm going to talk about is packaging atmosphere. The example that I have here is fresh meats, well those are processed meats but they are open to the environment and the picture on the bottom is a vacuum packed set sets of meats. So when we think about reducing the amount of oxygen, we will change the microbes that are present in that food product. And the reason for that is because unlike humans that we need oxygen right we can even have a plastic bag on in our heads for for long because we run out of oxygen. So some microbes like oxygen and some microbes don't like oxygen, and some microbes can either do with or without oxygen. But when we remove the oxygen from a package and we vacuum packed and we eliminate the oxygen or substitute the oxygen for another gas, then the microbial ecology it's going to switch a little bit. This has lots of implications for quality purposes right to stabilize the color and to reduce microbial spoilage, but all for safety. And the reason for that is because microbes such as clostridium botulinum that I mentioned before, and a really close relative of clostridium botulinum called clostridium perfringence. Those are very particularly clostridium perfringence is a very common organism to cause illness in humans, and those microbes don't like oxygen. So when we remove the oxygen if you're thinking about having a process that removes oxygen that you would have to talk with with your health inspector about that. But in the state of Nebraska and I assume that that is that is similar in other states, including North Dakota, you would need what we call a variance for the application of that reduce oxygen packaging or a process that removes oxygen. And so we need to make sure that once you remove the oxygen that the conditions are not conducive to the growth of clostridium botulinum that could potentially produce toxins and make somebody sick. Okay, so how are these things interacting right so I've mentioned the pH I've mentioned water activity temperature, oxygen levels, all of these things are interacting right they don't work alone. And maybe when maybe the title of my talk should have been a little different, I think that that this is obviously relevant to developing safe food products but maybe I should have just told you. This is going to be about pH water activity and how those things interact. But this is extremely relevant right so we as an extension specialist and and I'm sure that it's the same for other people we get a lot of calls and we get a lot of people that come to us asking us, is the pH of this product or is the water activity of this product enough to make it safe right so if you are thinking about developing a recipe developing a product, maybe have a prototype maybe you want to pilot it. Maybe you go into a commercial kitchen, and you want to do some testing and change ingredients and whatnot. All of these things are important to keep in mind because you want to make your product as microbiologically stable as possible because that will potentially reduce the probability of making somebody sick. So all of these things are interacting and the way that they interact to reduce microbial growth or even microbial growth is a little different, but I'll give you an example. The example that I have here is for the growth of clostridium botulinum, which is a very dangerous micro. Fortunately, it's not very common to find botulism cases in the United States, but it is a very dangerous organism. I'll ask you to take a super close look at the table, but the example here is at 68 degrees right which is very comfortable temperature for microbes 68 degrees is good for microbial growth or for growth growth of clostridium botulinum. The pH is seven so the pH that they tested was five, six, seven, eight and nine right so they go from acidic which would be five to or mightly acidic to neutral to might be alkaline or basic. At pH seven that is also good pH for clostridium botulinum to grow, especially when the temperature is comfortable. But if we see the water activity levels they evaluate different water activity level levels, and we see that below point nine six there is no growth of clostridium botulinum. So even if two of the factors are ideal for the micro to grow and potentially produce toxin, we can use the interaction with the third factor to control for microbial growth. And we see examples like this all the time we see examples like this let's say for staph aureus right so where Staphylococcus aureus companies toxin under certain conditions of temperature and pH and water activity, especially in the in the presence of oxygen, right so all of these enter all of these factors interact with one another, and we cannot just use one factor to predict right we cannot just use one factor to predict what is going to be or the optimal conditions for growth, because foods are complicated and so are microbes. So when we think about controlling microbial growth and food. What comes to mind is time temperature control for safety foods. And these are foods that require a time temperature control for safety to limit pathogenic growth or toxin toxin formation. And so they're maintaining these foods at a proper temperature reduces reduces the probability of food more illness. Some of you may be familiar with the food code, and the model food code that comes from the US FDA from the food code administration. Every state has a food code and it is typically modeled after the federal food code. I know that the North Dakota food code it's based on the 2013 US FDA food food code. So there, there may be some changes it hasn't changed significantly but there is some science that has been added since then. This is an excellent resource when you are thinking about developing recipes, improving the safety of your recipes, retail and institutional food service, anything like this, the food code is really the place to go and it's where the science is at. When we think about foods that require time and temperature control that can be any animal food or any plant food. So there are specific examples, we have sprouts cut fruits cut leafy greens cut tomatoes. Those things need to be refrigerated and only for a certain period of time. Otherwise, it will allow microbial contamination if there's any, any microbes present. These are some of the examples that are very historical right so think about garlic and oil mixtures. And those are for clostridium botulinum. And I remember when I was, when I was an undergraduate student and even growing up even before I went into food science that people would would always say oh garlic and oil garlic and oil it's such a big problem. Of course, lots of people don't know why, but it is for clostridium botulinum. Now there's other reasons why the food may be time temperature control for safety. And if a food that because of the interaction of water activity and pH is designated as a product assessment required. We'll see that in a second. That is a temperature control for safety situation. So the point that I'm trying to make here is that there's many different types of foods that have to be refrigerated that you have to apply a refrigeration or a hot holding to increase the safety of that product and we'll see examples in a second. Now, we're not going to go into super high details of this but there are tables that come from the food code on the interaction of pH and water activity to control spores in foods that are heat treated. Okay, and these foods are also packaged so there are different situations and this is part of the utility of the food code that you can go and see what are conditions that approximate your process a little better. And determine if those two values of pH and water activity interacting a way that will make your product non temperature control for safety, basically shelf stable, right that it's a little more shelf stable, or if it requires a product assessment. And when when we think about requiring a product assessment is really not it's it's can get fairly complicated right because foods can be very complex in the way that they interact in the way that microbes interacting food. And so we need to do individual product assessments for products that have a pH that it's maybe closer to neutral and a water activity that it's closer to one right the closer to one, the more water there is for microbes to multiply. So we want to make assessments and this is for package foods. If we go to the next table, this is for foods that are not going to be packaged, even if they are heat treated or not heat treated. Right and so sometimes we can classify them as non TCS TCS foods so they are a little more shelf stable, or we need to do product assessments to make sure that the interaction of pH and water activity is sufficient to control for microbial growth, or if it's going to require refrigeration. Right so in a lot of these cases, the outcome of this product assessment is that the food needs to be refrigerated, or maybe that the food needs refrigeration and reduce oxygen packaging right so when we are thinking about developing products. These are some of the interactions that we want to keep in mind. And so I'm going to give you a couple of examples of time temperature control for safety foods. So of course meat and poultry products always have to be refrigerated there are very few examples of shelf stable meat products that are ready to eat that are shelf stable of course, such as beef jerky. Things that are dehydrated right smoke dehydrated cure. So there's certain categories of meat products that can be shelf stable. Now most seafood including cooked seafood and sushi. If you're a restaurant or if you are thinking of offering sushi at a restaurant that you own. It is might be the same case in might be the same case in North Dakota but in Nebraska you need a has a variance right so you need to have specific permits and specific oversight from the regulatory authority to be able to make sushi restaurant. Now most fruits and vegetables and fresh cut produce are temperature control for safety, because they allow or it's a it's a those are matrices food matrices that where my troops can grow boiled or steam cereal products such as rice right and so we we know that there are starchy foods that are pretty easily contaminated with things like bacillus serious right and so we can get intoxicated with a toxin we can get sick with a toxin that it's producing these very starchy foods, and there's many other products as fresh milk and was milk products. Some of the exceptions would be fermented meal fermented dairy products that are a little more stable. And even if left on outside of refrigeration there unlikely to cause illness. So these operations should be followed, should follow required temperatures and times according to the food code. So if you need to have a product that it's refrigerated based on the product assessment, then it has to be under 41. If it has to be hot, it has to be above 140. And if you guys remember from the first couple of slides, this is the temperature danger zone we don't want my we don't want foods to be in the temperature danger zone because that it's where my troops are actively multiplying. When we are cooling a food product and cooling is extremely important cooling is almost as important if not. Yeah, it is as important as cooking. So when we cook a food product we eliminate microbes from the food product, but when we cool down product we are also eliminating other indirectly preventing other microbes. And so when we think about Salmonella and E. coli and Listeria we are killing those with the cooking step, but when we come down to refrigeration in a control way, we are controlling for things like clostridium perforage and synclostridium botulinum. And then of course let's think about reheating things that are already cooked that has to go to 165 internal temperature for 15 seconds. It is really important to prevent temperature abuse of these products because at that temperature it's when my troops will grow significantly faster. These are some examples of things that are not temperature control for safety so fully retorted and fully dried and salted seafood right so things that are shelf stable. Think about process fruit and vegetable products such as I like to eat a lot of the fruits that are already coming in a in a little cup right that come in some some juice with no sugar no sugar added but I love to eat that. Because I'm really bad at keeping fruits and vegetables at my house. So those things are shelf stable and therefore are not temperature control for safety I put them in the fridge just because I like them cold but they don't have to be in the fridge. Most baked goods baked goods without a feeling and the feeling it's typically the most important thing when it comes to safety, because the feeling it's the one that can that can be contaminated with things like listeria monocytogen is or stuff or is and produce a toxin. Let's see other things traditional sugars and syrups right so those have a very low water activity because there's so much sugar that there's it doesn't really allow for microbes to grow. And then one that it's interesting is hard boiled eggs with the intact shell, but so if the shell is there then that product doesn't have to be refrigerated. And now as a food microbiologist as a food safety expert, I don't like to eat eggs that have been left out for a really long time, even if I know that it has an intact shell, but. But it is not a temperature control for safety and it is unlikely if it's cooked adequately it is unlikely to make anybody sick. Okay cottage foods when we think about developing food products now you guys are expert food microbiologists based on this overview that I've that I've given you and one thing that it's really important about cottage food foods. The regulations are a little different I checked the North Dakota regulations and compare those to the Nebraska ones. And I think you guys up there are a little more permissive about what are some things that can be sold as cottage foods. I think in Nebraska we're still being pretty conservative about the types of things that we can sell, but cottage foods really allow small time producers to use appliances in their homes to bake, cook, can pickle, dry or candy certain low risk foods for sale. And the low risk is the low risk portion of this sentence or this this statement is the thing that kind of worries me the most because we know as humans that we all assess risk differently. Right so if we don't have the tools to make an informed decision then we will be making risk decisions or risk assessment decisions, maybe incorrectly. State laws in general require all other food producers to process foods in licensed kitchens right so when we have, you can have licensed kitchens of course where you go and do different products that are under state or maybe local city or tribal regulations. If a consumer buys foods from a neighbor friend or even an acquaintance then that consumer presumably knows enough about the operation to make an informed decision. And that is the value of cottage foods right so we are buying from somebody that's making something of their home. We know this we know this person we appreciate the love that they put into cooking these things and so I'm going to buy from my neighbor or I'm going to make this and sell it in in my vicinity. Right, and so these are not things that are fully commercialized. Although, just like in Nebraska in North Dakota you guys also need to have a label that this was not produced in a kitchen that was inspected and that is important. Now one of the last things that I'm going to talk about thinking about those producing safe food products, especially at home or for cottage foods or entrepreneurship, anything like that is food safety hazards. I've mentioned lots of hazards already different microbes different, including bacteria and viruses and parasites and I don't expect you to remember all of those names. But I what I do want you to know is that the hazard is the actual agent that causes illness or injury, and it can be biological as I mentioned before but it can also be chemical or physical. And there is another term that it's highly related to hazard, and that is risk, right in that risk, it's the one that determines if somebody's going to get sick. The hazard is the actual agent that causes illness or injury, but the risk is the probability that we're going to get sick. And that probability is determined by how frequently we find the hazard in the food product, and also the severity of the illness that it's caused by the hazard. So not all hazards carry the same level of risk because some hazards will be a little milder right so think about an adult healthy adult that gets salmonella. Well, you're going to spend maybe one day 24 to 48 hours in the toilet right maybe you are going to have some physical discomfort but it's going to be self limited. But if you get clostridium botulinum, even as a healthy adult you can have an extremely negative outcome of that illness, right. So, so the risk of those hazards is different. Then do remember that hazard and risk are different things. And then one of the last things that I'm going to tell you the last couple of slides is also remember that growth and survival are different things. We're talking about how microbes can grow in foods right so there are optimal conditions for microbial growth in foods, but the non optimal conditions may allow the microbes to survive. Even though they are not actively multiplying just controlling for those factors such as pH or water activity may not be enough and that is the reason why we tell people clean separate cook and chill. Right so cooking to an adequate internal temperature chilling at the rate that we need to do so to prevent outgrowth of spores. Then we want to clean to prevent cross contamination we want to separate to prevent to prevent cross contamination. So all of these things that only the way that microbes growing food but the way that we actually handle food has lots of implications for microbial food safety. And then lastly, I'm going to briefly talk about regulatory oversight for food safety when we are thinking about designing food products. We know of course that most of the food production in the US falls under inspection and enforcement by the FSIS if it's meat poultry processed eggs or catfish. And the USDA pretty much handles everything else that the FDA excuse me the FDA handles pretty much everything else. Right so they are in charge of enforcing and inspecting for adulteration and misbranding. And of course they are involved in interest state commerce so if a food product crosses state lines. That requires federal oversight right. State inspection is very important and state health and ag agencies overseas interest state commerce, sometimes like in the case of Nebraska they can. They can outsource federal inspections for the FDA. I don't know if it's the same in North Dakota. And then there will be other regulatory guidances and ordinances that could be city municipal or tribal agencies. And so it's always better to check with the health and act departments in your municipalities in your states to make sure of what are the appropriate regulations that you need to be compliant with. And so with that, I think we have maybe 10 minutes for four questions. And I will try to respond to any questions in the chat and thank you so much for your attention. All right, well I have a couple questions for you and the participants have been helping each other out with some links to other resources. I don't want to check those out as well such as where is the food code and that kind of thing. But an earlier question was, can a virus, even though it does not multiply and food be carried in food and spread to humans who then eat it. That's a great question. So, okay. Foodborne viruses do not multiply, right? So now, can viruses survive in or on a food product for a really long time? Yes, they can, right? So let's think about two very popular foodborne viruses. The Norovirus, right? It's what we call the two bucket disease. You can be puking and pooping at the same time, which I'm sure it's not fun, but that is the two bucket disease, right? And not everybody gets the two at the same time, but some people do. So Norovirus and Hepatitis A, right? So two of the main foodborne viruses. And actually some of the most common etiological agents or causes of illness, foodborne illness in the US and actually Norovirus is the number one, right? So when we think of all of the microbes that produce foodborne illness in the US, Norovirus produces about 55% of all of the illness cases in a single year. So it's a big deal. Now, those microbes can potentially dwindle and concentrate over time, right? But they can also be carried over. And the fact that the virus is present or maybe there's some generic material that it's present doesn't mean that it's going to make people sick over time. There are environmental conditions that will determine for how long the virus is going to survive, right? So not only intrinsic factors of the food products such as water activity and pH, but for viruses, things like UV light, right? If the virus is exposed to the sunlight, that will have an effect. Typically when we change the oxygen concentrations that doesn't really have an effect, but relative humidity does have an effect, right? So there is an optimal relative humidity for viruses to survive just because of the structure of the viruses. So the short answer is yes, they can survive for a really long time in or on food products. Now, the infectious portion of the virus or how much of that population is infectious and can make somebody sick will decrease over time based on multiple conditions, right? And so we don't have time to go into all of those and that is very product and process specific. But then the other thing is can foods act as a formite, right? Can act as a formite for microbial contamination? What that means is can viruses be present on a food product? Then I touch the food product and then I bring my hands to my mouth or my eyes and can I get sick? Well, it is an unlikely scenario, but it is still plausible, right? We see a lot of those with the SARS-CoV-2 virus. We go under the assumption that COVID-19 is not foodborne. But there are some people pushing for the hypothesis that you can get COVID by touching a food product that's contaminated and then bringing those to your mouth or your eyes. And one of the things that we do in my lab is to try to please prove that hypothesis. And so we work with viruses that are very similar to that. So I'm going to ask the participants to take a look at your shelf behind you and there's a little microorganism type of animal stuff thing. What do you guys think that is? Which one is that microorganism? Yeah, that is my only one and I really want to have more. I have the whole set. I think that's E. coli, right? This is an E. coli. Yeah, there you go. This is an E. coli. I really want to have them all. Yeah, I have a whole bin of them. I have another question for you. If food manufacturers want to add a chemical preservative to prevent mold or bacterial growth, how would they decide on the type and the amount to add and you know of restrictions on chemical preservatives for the overall food industry? Yeah, so great question. So when we think about the ones that we want to add the first thing would be to check the regulation to make sure that that is not that that is an additive that it's allowed in foods right and so we can go to the FDA or the USDA. And there are lists of approved chemical additives for foods, right? So the big risk that we run into with chemicals is that if you add them at an excess concentration, they may act as a chemical hazard, right? So we talked a lot about biological hazards, but if we violate the concentrations or the tolerances of that chemical, then that can make somebody sick. So think about nitrites in cure meats or think about benzoids in confectionary or propanate salts in bakery products and things like that. So how do we know what is the adequate concentration? It is based on the residual concentration in the product, right? So the residual concentration is really what we want to measure. And so we put, let's say, a specific amount and then based on the amount of product that we are producing in our formulation and then we measure how much is in the recipe. And so that is what it's going to tell us how safe that is. Now, the regulation will tell you what are the ranges of concentrations that you are allowed to use in specific situations. And I would advise that if it's something very specific that you can't get from the regulation to reach out to your health department or to regional offices of the USDA or the FDA and they will be able to tell. Okay, thank you. And I wanted to let everyone know that Byron slides are posted on the events page. So you can take a closer look he provided some great information to all of us today and I want to thank you for that. It's been a very interesting talk and I think that's it for questions so thank you very much. Thank you for having me. This was great. Thanks everybody.