Hello friends. I'm Chad Karr, Extension Meat Specialist within the Department of Animal Sciences at the University of Florida. I'd like to welcome you back here for this our fifth week of The Meat We Eat. This week we're going to discuss, honestly, one of my very favorite topics as a scientist, researcher and teacher, Fresh Meat Palatability. I'm a pretty heavy meat eater and I like to discuss the things which impact the palatability of fresh meat. And so, as we go forward and we think about why we cook meat in a modern consumer perspective. If any of you have eaten raw meat, and you think about the comparison of consuming raw undenatured animal protein as compared to cooked meat. There's obviously a overwhelming difference there in terms of the flavor and the mouth feel that the product has. And so there's a cascade of biochemistry associated with what goes on when we cook meat. And we denature those proteins and we honestly improve the palatability of the product as compared to raw tissue. But it's not just flavor and tenderness and juiciness, and appearance. Those are big contributing factors to why I enjoy to consume cooked meat as compared to raw meat. But another reason is that and probably maybe the most important reason relative to consumer education. Is that when we cook products, particularly how important it is when we think about something that is not intact. Ground product, or something that's been needle tenderized or whatever the case may be. That product needs to be cooked to a reasonable degree of doneness in terms of safety. So, why do we cook meat? Two main reasons. One, is to improve it's safety. Kay, because on the inside of that product, if its been ground or needle tenderized, the inside's not naive to perspective pathogens. The other reason is, these other parameters to improve the quality of and then shelf life and keeping quality as well. But that's the big cascade of reasons. I hit briefly on some of these parameters. This is not about chemistry class. But be mindful that po, protein denaturation is we have the Maillard Browning Reaction on the surface. The little bit of carbohydrate that we've got there and what goes on with fats and nutrient loss. All of that is a vital component of what gives meat its cooked flavor, ultimately, and how it's different compared to fresh meat. kind of getting back to that first component that I said is probably the most important parameter relative to why we cook meat. Is that I could state right here, pathogens that can really make us sick. Particularly if we're immunocompromised. They can live within the GI tract of food animals. And as that gets converted to the surface of the carcass. And then it is unsure if we've got a comminuted product. Then it needs to be cooked. If you have comminuted product, it needs to be cooked to 160 degrees Fahrenheit. Because the inside of that muscle is not naive to pathogens just like it says. So all ground and nonintact red meat, we'll talk about was nonintact means here in just a little bit. But needle tenderized products. They need to be cooked to 160 degrees Farenheit with the good thermometer. Poultry a little bit higher than that. So if we have something that is intact then we can cook that product to 145 degrees Fahrenheit. And then hold that product for an additional three minutes at that time, at that temperature. And the product that if it's intact, then it hasn't needle tenderized, it's wholesome. All right, so again, I've stated multiple times in this class for the Coursera platform and I'm trained as a meat scientist. And the things probably that I enjoy the most would be discussion of factors that impact whole muscle meat palatability. And what palatability is of whole muscle cuts is exactly what you see right here. And this is different if were talking about, you know consuming grains or some other produce product. What palatability would be, would be different as upon that different commodity. But with meat, tenderness, juiciness, and flavor are the three components which drive its palatability. How do we measure those things? Okay? So we don't really have a flavor machine, okay. We don't really have a juiciness testing machine, either. Now, we can make inference as to the cooked meat flavor of products through trained panelists which serve as very objective measurements. We can have consumer panelists, which are certainly more subjective. But we can make inference to flavor. We can make inference to juiciness. We can do fatty acid profiles, which are going to have a big influence of, of fatty acid of the product. It's going to have a huge influence on the ultimate flavor of the product. But, we don't have a machine that could put his chicken breast inside in, tastes good. We don't, we don't have that, okay. For juices for instance, like we stated, we can talk about sensory panel characteristics from trained panelists to consumer panelists. We can certainly quantify cooking loss or water holding capacity as that associates with the juiciness of the product. But we don't really have a juiciness machine, put it in here, it's juicy, we don't have that, okay? We do have ways to more objectively quantity cook meat tenderness. And that would be as stated here, Warner-Bratzler Shear Force measurement. Or something similar to that would be Slide Shear Force measurements. Which we have cooked whole muscle, steaks or roast. They're presented in a given way relative to the orientation of the myofibrils. And then we essentially use instrumentation to mechanically sever that product to measure the amount of force as to which it takes to do that. To kind of quanti-, to simulate the human bite, but that's how we measure palatability in meat science as a whole. Okay? What things influence palatability? Fat, the amount of fat, the kind of fat that we have. Huge driving component as to the flavor that we have within meat products. Big, big driving component. And just like the slide says, and I've heard Dr. Gary Smith talk about this research that they did some, a long time ago. But if we have pork that's ex, essentially denuded and has no fat on it, and we have. Beef fat with it, then the consumers would think that product would be beef. And likewise, whatever the kind of fat that we put with that product, that consumers generally associate with the, the flavor of that product. That's ultimately what the product they'll identify it as. So not only is the species definition or is that associated with the fatty acid profile. But what we've fed animals has a big impact upon not necessarily the amount of fat definitively, but the kind of fat that we'll have. So, we hear lots of stuff about differences within international markets with grain-fed or pasture-finished or grass-fed beef, for instance. And so, it certainly influences the fatty acid profile of the products. And which ultimately the differences in fatty acid profile impacts the flavor, or can, impact the flavor of the product. And so collectively just, just in general as we think about a, a 50,000 foot view. Comparing grass fed product that, to a, a, a com-, or a U.S. commodity grain fed product, grain, grass fed carcasses. They'll tend to be little, leaner externally. And, within side the carcass, within the muscle as well, they'll tend to have lower, lighter weight carcasses. They'll tend to have more, more off-flavors, and those off-flavors are driven by this difference that we have here. In polyunsaturated fatty acids, as compared to grain-fed beef, and that's what we'll hit on here in just a second. So as we look here, and let's go through this final slide which as it kind of quantifies this difference. When we see comparing grain-fed commodity product with a grass-fed product. Which was some of Jennifer Laheska's work when she was at Texas Tech. And it was a composite of samples from, from multiple grass-fed beef outfits. We can see here that certainly there is a difference between grass-fed and grain-fed beef, in terms of omega-3 fatty acids and CLAs. Which both collectively would be quantified as polyunsaturated fatty acids. There's definitely a difference there. And then, also we can see here that those products do look different. They can look different. This is a picture that was taken of a little research project that we did here at the University of Florida with some grass fed product. Now we'll talk about I'm not certainly, because the fatty acid profile is different it certainly impact the flavor. I don't know, that it definitely impacts the healthfulness of the product. And we'll talk about that. Both of the are healthy products. And, and, certainly part of a balanced diet. And we'll talk about that a little bit more when we have our, our last, PowerPoint presentation associated with the meat we eat lecture series. So, we talked about the kind of fat and the influence that that can have on flavor. The amount of fat within the muscle, within a ground beef patty, whatever the case may be, we know it has a huge impact on flavor. And then ultimately on mouth feel and everything else associated with consuming animal products. More fat, more flavor. There we go. More fat, as a whole, as that is rendered, we're going to have more liquified oil within our mouth and then, not only that, that will help us to salivate. And then we'll have the perception that the product is more juicy. This slide picture here is one that I probably should of had there in our grading presentation. But that would be the slide snapshot or screenshot or instrumentation differences. That would be dictated in a large scale commercial beef processing facility here in our country. And it just kind of documents the the touchscreen panel that the USDA mass grader would utilize. Okay, so as we go here from Prime down to Select in these pictures. No question about it, fat is easier to penetrate than it would be for animal protein, or, muscle protein, myofibrillar protein. And so there's improved tenderness with a greater amount of fat. The prime steak are probably going to be somewhere around, I dunno, upwards of 10% fat within the muscle. Compared to the select steak wich is, eh, probably 2 and a half to 3 and a half % within the muscle. And it's true that as we have more fat within the muscle is serves as an insulatory component to prevent us from overcooking the product as well. All right. Now, as we continue to talk about palatability here, let's hit on the component. Which is the most consumed beef product in the U.S., and that's ground beef. So the definition of ground beef, relative to USDA, is just like it says: only whole muscle cuts. It must be less than 30% fat. Now, the definition of hamburger is actu, is different, okay. That is according to USDA labeling regulatory compliance. It can contain some organ meat and binders, but it must be stated on the label. And if you buy ground beef that says specifically round, if it has a subprimal on it, it actually must be from that subprime. Okay? As we think about palatability of ground beef as a whole and how we make ground beef commercially, just generally, across the board. It's not going to, the, a ground beef patty or a chub of ground beef that you would purchase as an international consumer. That product or that ten pound chub of ground beef probably comes from more than one animal. This why. 'Kay? We're going to take the picture that we see of the fed carcasses on the one side. We'll take the fattier cuts. Those that would be, oh I don't know, the plate and the navel, somewhere around 40% fat maybe. And then we would have the leaner parts of that carcass and the leaner parts that we would have from imported trim possibly. Or the leaner parts that we would have from a a non-fed cull breeding animal like we see with the other picture. Which is going to be you know, in excess of 85% lean. We will grind that and then blend it to a targeted fat percentage and so that's kind of why we were getting at it. You know, if you buy a 10 pound chub of ground beef, the odds that that comes from only one animal, eh, probably not. Probably more than one represented within that chub because that's how it occurs commercially. Okay. Other thing, but one thing that I didn't mention, if to talk about the, the palatability of that ground beef product. The driving force to consumers' satisfaction with that ground beef product, all of the things consistent, would be the amount of fat within it. So if we show consumers, the ground beef products of differentiation or different lean fat percentages. They would prefer the one that's more red or a higher lean percentage. But when we cook that product, they'll certainly prefer the product that's got a little more fat, in general, so. Just something to kind of consider as it associates with ground beef palatability. All right. I already mentioned this since we talked about beef grading. But as an animal ages, the complexity of the connective tissue associated within all facets of that construction of the muscle. Around the epa and para and endometrium even becomes more sophisticated as that animal becomes older. And we have more collagen cross links. And ultimately, that product becomes more insoluble or the collagen becomes more insoluble. Making the product tougher to consume from a tenderness perspective. So that's one thing that we know for sure and collectively animals that have advanced age. We need to help those products out in terms of further processing. That would be those animals of, like we've talked about, cull breeding the animals, they would go into making ground beef blends, let's say. Also, other things which impact the palatability of whole muscle cuts would be the location it comes within the carcass. So just generally across the board. Animals, or muscles of locomotion. They will tend to have more and more sophisticated connective tissue as compared to muscles of posture. And so cuts that come from the round or chuck or the leg or the ham or the shoulders, compared to loin cuts. Will tend to need to be cooked for a longer, slower period of time due to greater amount of connective tissue collectively. So, this right here, this kilogram of shear force quantified different muscles within a beef carcass. Relative to their ultimate shear force of the simulation of a human by the amount of instrumentative force that it takes to sever that product. And so Psoas major or Tenderloin are somewhere around, I don't know, six and a half pounds or so. And anything that would ultimately bess than, less than that four and a half kilograms or ten pound mark. Would be deciphered by the average consumer to be acceptable or intermedian in terms of tenderness. And those things that would be on the top side of the four and half or ten four and a half kilograms or ten pounds would be deciphered as tough. And so as we look tenderloin and certainly not a muscle of locomotion it's on the inside of the body cavity. If we look at ribeye that's a muscle of posture as compared to the brisket or deep pectoral muscle every time he moves there that's moving. So that kind of supports the ideology of what goes on there in terms of connective tissue and it's amount. Relative to differentiation in muscle type and function. All right, degree of doneness, and the impact that it has on tenderness. kind of a fine line here. Okay? So as we cook a product from raw, there will be a stage of tenderization like we see down here. So between somewhere around 85 and 145 degrees Fahrenheit. There's going to be enzymes which contribute to improved myofibrillar tenderness. And we're going to have solubilization of these collagen crosslinks as well in the presence of water. So it will tenderize. But then also some, somewhere around that same temperature is that cutoff point that those myofibrillar proteins, the myosin and actin. They'll start to get hard. 'Kay? So there's a fine line up until we get to about medium rare. We're probably going to, we have not allowed effective tenderization, but we get much past that. And we probably start to get in the hardening of these myofibrillar proteins and we give up tenderness. So, collectively, the, just like we were talking about in terms of safety. If we have a, whole muscle intact, cut, red meat cut, that has not been needle tenderized. Then, it can be cooked to about 145 degrees Fahrenheit. And collectively, that probably maximizes the palatability. So, yeah, we have tender cuts. Those that would be from, rib or loin as a whole that can withstand that dry heat cooking and that connective tissue constriction some. They, that'll work fine and we'll end up with highly palatable products. This will be examples of dry heat shorter time cookery methods broiling, pain broiling, grilling, deep fat frying. All are examples of dry heat cookery methods. Anything where you've added water obviously it would be a most heat cookery method. >> And that works with some cuts which give up more in terms of tenderness, which innately have more connective tissue. And they probably need a lower temperature, moist heat cookery to help solubilize some of that collagen like it states there. Cuts that are kind of intermediate, in terms of tenderness. We can maybe do some stuff to try to improve their palatability and we can marinate the products prospectively. We can certainly utilize dry heat cookery methods. But maybe for a longer period of time, we wouldn't want to take and we've got something we think is going to be pretty darn tough. We wouldn't want to cut steaks from a brisket, for instance, and then put that on our grill. We wouldn't be very pleased with that, probably. And cut those across the grain to improve the ultimate tenderness of the product, or perception of tenderness as you consume it. So these cuts here, as it shows for the primary red meat species that we talk about. They all kind of be, eh, they might need a little bit of help to maximize the palatability of the product. 'Kay. As we, other things which impact palatability. As a whole, as an animal, as it is slaughtered, 'Kay, we talked about what goes on in terms of postmortem muscle metabolism. And the integrity of the sarcomere, okay. As an animal as a carcass is aged postmortem, what happens there're enzymes that are calcium dependent. This calpain enzyme, and in vivo calpain works to help us in terms of protein turn over, wound repair, all that kind of stuff, okay. But in the postmortem muscle system, what they do, they still continue to work in the presence of calcium. And they will break down some of the proteins there at the end of the sarcomere. There at those z lines so it works to improve palatability or the tenderness of the product. Predominately by breaking down those z line proteins like it says. So for whole muscle cuts, if we allow to age that product for 14 to 21 days that pretty much will maximize the tenderness of that product. And anything over that we might still have some marginal improvement in tenderness. But it's done most of what it's going to do, actually within the first 11 days; particularly within beef. But yeah, if we do that that, the, done what we can in terms of a post mortem aging perspective to improve tenderness. And allow those endogenous proteases to work. What else can we do to influence palatability differences? How we age the product. If it's exposed to oxygen or if it's been dry aged, there's some renaissance within our country. In, in terms of niche charcuterie programs and niche butch shops. Which would like to add value or market products to the high end white table cloth restaurants. Because it imparts a different flavor when beef has been dry aged. As compared to aged like everything else is in a vacuum sealed anaerobic bag system. So there's going to be differences in oxidation, a little bit of difference maybe in spoilage, bacteria, microflora. That affect that difference in flavor that you have there. So we can see vacuum sealed product versus dry aged product and how that would work. Other things that influence the flavor and, mouth feel, of red meat products. Would be what we see here in terms of the rate of postmortem glycolysis. This is absolutely essential within fast metabolizing, red muscle fiber type species, predominantly pork, and turkey, and chicken. But the components here that we will talk about really impact the pork industry mainly. And so if that rate of postmortem glycolysis, if it happens really fast, okay. And we denature the proteins we have accumulation of lactic acid really quickly. Due to maybe some term, short term stressors there in the early ante mortem period. And right there if the temperature stays high on the slaughter floor. What will happen, that will exacerbate what's going on there in terms of rate of postmortem muscle metabolism. And when that temperature's high, it kind of denatures those proteins and ultimately we'll end up with pork that'll be very pale and soft and white. And you think, oh, well this stuff's gotta a lotta fluid here in the package, and it'll be juicy. No, no. That's probably actually the antithesis of that. It it can't hold onto its own water. And so, when you go to cook it, and further stress it. We're just going to lose more water. And it will probably end up to be dry and have small flavors. It might even be kind of tough. So, there you go. As we think about this degree of doneness parameter. And how that associates with, ultimately, the, cooked meat satisfaction. The, these degree of doneness here. That, what that would associate with. So, very rare. We'd see that, somewhere around 130 degrees Fahrenheit. That 145-ish, generally, is what would maximize the palatability of intact whole muscle red meat cuts, just like it states right there. So, for some cuts, which give up some, in terms of palatability. What can we do? So, technology that's been utilized to add value to kind of marginal intermediate quality meat, is enhanced. And so essentially, what enhancement does if we have really good quality meat and we enhance it. Then it probably makes it a little more mediocre honestly. If we kind of have poor quality meat and we enhance it then it makes it better. 'Kay so it kind of standardizes and brings everything to the middle is honestly what enhancement does. Something that's became pretty popular here domestically relative to retail markets and, and large scale retailers particularly. So, as a whole what enhancement entails is that we have a pork loin let's say and it weighs 20 pounds. And when it comes out the other side, we're going to add ten pounds of enhancement solution to it, or two pounds, 10%. So it comes out the other side weighing 22 pounds. So we have added water, predominantly, as the vehicle, salt, as a flavoring, and phosphate. Phosphate, it kind of opens up that protein lattice and allows us to bind water more effectively. We might have a antimicro, a natural antimicrobial or a natural antioxidant in it as well. But enhancement is utilized pretty extensively within our domestic market at retail for sure to add value. And ultimately make the product so that don't do a very good job cooking and you temperature abuse it. It'll still be pretty highly palatable. And in terms of marketing to food service in this country, we extensively utilize this technology. And this picture here is actually the picture of what we here at the meat lab of a, of an enhancement solution. But the principal for a needle tenderization or blade tenderization is just the same. But we would have a physical disruption of those miofibirils prior to fabricating let's say a top sirloin butt into retail portion size cuts. To be sold at any major food service outfit and it improves the consistency and the palatability of those products as well. Some things that are also used in, in some quantity, particularly, or, predominantly with animals that are of advanced physiological maturity. We could take, if you go to Las Vegas and you buy the, the $8 beefsteak buffet,. You're probably not eating dry-aged, prime USDA beef, okay? You're probably eating something that's of a little more marginal quality. But it's probably, they're, they're going to make it as consistent as they can. And so with that, something's probably been enhanced with some of these tropical plant enzymes. Which help to, to break down some protein within them. So, if you think about Adolph's Meat Tenderizer it includes some of these tropical plant enzymes. Which certainly help to improve tenderness of the product. And due to the different action points or the different, reactivity temperatures of those enzymes to breakdown protein. Papain, Ficin, and Bromelain, they are respectively made from papaya, and figs, and pineapple. And they work kind of in a composite to make a more tender animal protein product. So, that's what we have. Join us next time for the Meat We Eat.