With the school year starting, both in person and virtually, your kids may be looking for a science fair project. Rather than focusing on a solar system or volcano, here is a simple project that can open up your kids to the world that is meat science!
All that is required for this project is canned and fresh pineapple and a box of jello. Making jello with canned pineapple works great! The jello will set up as expected and even makes a great treat.
Making jello with fresh pineapple, on the other hand, does not work. The jello will not set up and will remain a liquid even if cooled for longer than the recommended time period. This is due to an enzyme found in pineapple called bromelain. Bromelain breaks down protein, which makes it a great ingredient in meat tenderizers. It is also what causes some people to say that their mouth becomes sore if they eat a lot of fresh pineapple. During the cooking process while canning, bromelain is broken down and is no longer functional. This is why canned pineapple works to make jello, but not fresh pineapple.
Now what does this have to do with meat science? Store bought meat tenderizers often contain bromelain or papain, which is a similar enzyme found in papaya. Similarly, meat naturally contains an enzyme called calpain. Calpains are activated by calcium and work to break down protein. They are responsible for the tenderness improvement that occurs when meat is aged. Aging meat, or holding it in a refrigerated environment or a period of time, allows more time for the calpains to be active and to break down more protein. This improvement in tenderness makes for a better tasting steak.
This experiment would also make a great 4-H project. Students could pair the jello and pineapple with the science of aging and tenderness or use it as an introduction into talking about marinades and dry rubs when cooking meat. Either way, it is a simple project that contains a lot of science! It may just be the opportunity your kid needs to spark their interest in a future in meat science!
Last week I had the opportunity to be part of recording a webinar for the Nebraska Pork Producers Association Pork Mentorship program about my experience getting involved in meat science and opportunities within the industry.
I didn’t get involved with meat science until I was in college. It wasn’t until I snuck my way into an upper level meat science course my freshman year that I was introduced to this career path.
What drew me to meat science is that it is really all encompassing. Not only do you have to understand livestock production in terms of genetics, nutrition and handling, but there is also a whole host of things can influence meat quality and safety after the animal has been harvested. The process of getting a safe, tasty product from the farm to your table is extensive. Meat science is also a great way to relate to consumers. Not everyone has had the chance to work in a feedlot, but most people have eaten a hamburger. Connecting the story of agriculture through the actual food people consume is a great way to promote the industry.
Through great classes and opportunities in my undergraduate and graduate programs, I was able to learn more about the industry and the science behind meat production. This led to my current role in youth meat extension for the University of Nebraska-Lincoln.
Now, my story is heavy on the academics. I love to learn, and higher education was a good path for me. However, there are so many more ways to get involved in the industry than just working in academia. Being involved in the meat industry can involve a wide variety of careers. Below are just a few areas that barely crack the surface of opportunities within the industry:
Livestock Production and Health: What happens on the hoof is incredibly important in determining the quality of the product produced. Sickness, stress, bruising, all can lead to later problems with the carcass. Combine that with genetics, diet and environmental factors, and people with roles in this area can make huge impacts in the meat industry.
Research and development: Everything that you see in the grocery store that contains meat has been researched. This includes determining the safety of the product, nutritional value, flavor, shelf life and best packaging for each product.
Industry: Packing plants or butcher shops are what most people think of when considering careers in the meat industry. The fact is, they do provide a lot of opportunities. From line workers, management, marketing, and food safety controls, these businesses are incredibly important to the industry and provide thousands of jobs across the country.
Government: Food safety and meat quality are determined with government oversight. Additionally, jobs in policy, trade, and labeling, all impact the value of the final product.
Technology: The amount of technology and automation within livestock and meat production blows my mind. From feeding systems for the live animals, to machines that assist in harvest and fabrication, to the packaging that holds the final product, the technological advancement in the industry is incredible. Careers developing and maintaining these technologies are abundant.
Like I said, this list is just the tip of the iceberg. With the growing population and more mouths to feed, career opportunities within the meat industry will only continue to grow. You don’t have to be an animal scientist to be active in the meat industry. I encourage you to look into the world that is meat science, you may be surprised to find that it is right where you belong.
This post was co-written with Nebraska Extension Educator, Randy Saner, and originally posted on the UNL Beef Extension website on August 1, 2020. The link to the original publication, which includes more graphs and reported data, is included at the end of this post.
Consumers who buy a live animal from a local cattle producer or 4-H member for custom processing are often surprised by the amount of beef they receive, the amount of freezer space needed and that they did not get back the entire live weight of the animal in retail cuts. This article will discuss how to estimate how much meat you will receive when purchasing an animal to harvest.
Dressing Percentage is an important term to remember as it represents the portion of the live animal weight that transfers to the hot carcass weight.
Dressing percentage is calculated as: (hot carcass weight ÷ the live weight) x 100.
The hot carcass weight (HCW) is the weight of the unchilled carcass in pounds after the head, hide and internal organs have been removed. For most fed cattle, the HCW will be approximately 60 to 64 percent of live animal harvest weight. For example, a 1400-pound animal with a hot carcass weight of 880 pounds has a dressing percentage of approximately 63%, which is calculated as follows:
(880 hot carcass weight ÷ 1400-pound live weight) x 100 = 63%.
It is not uncommon for the buyer of a live animal to question, “The dressing percentage of my 1400-pound steer was 63% but I only got 550 pounds of meat – where is the rest of my meat?” The calculation of dressing percentage is based on hot carcass weight. The hot carcass weight includes bones, excess fat and moisture loss that will not be packed and wrapped for home consumption. The hot carcass weight is not the actual amount of meat that the consumer will put in his or her freezer.
Many factors can affect the dressing percentage. Anything that adds weight to the live animal but does not appear on the carcass will lower the dressing percentage. Factors that might add to the live animal weight but not be included in the hot carcass weight include:
Mud and/or manure on the hide
All beef animals are not created equal. Therefore, the dressing percentage is not consistent from one animal to another. Some of the primary factors that influence the dressing percentage include breed of the animal (dairy vs beef), live weight and how it was finished (grain fed or grass fed). The table below shows the relative dressing percentage for various types of beef animals and background conditions.
A beef carcass is composed of 70 to 75% water. As it is chilled, water evaporation will cause the carcass weight to decrease. It is not uncommon for a chilled carcass to weigh 2 to 5% less than the hot carcass. That means our example 880-pound carcass could lose nearly 40 pounds during chilling solely due to water loss by evaporation!
After a carcass is cooled, it will be further processed into the retail cuts you bring home. The carcass is split in half, and further separated into “primal” (or wholesale) cuts. This process is referred to as “breaking down the carcass or fabrication.” Beef primal cuts in the front-quarter include the rib, chuck, shank, brisket, and plate; while the hind quarter is composed of the flank, round and loin (short loin and sirloin). The table below shows the typical weights and percent of a carcass of various primals from an 880 lb. carcass.
Wholesale or primal meat cuts will be further processed into sub-primals or retail cuts. The basic concept of fabricating beef retail cuts is to separate tender muscles from less tender muscles, thick muscles from thin muscles and fat from lean portions. What remains when bone and fat are removed is referred to as yield, or the percent of boneless, closely trimmed retail cuts. For example, according to the National Cattlemen’s Beef Association publication entitled “Beef Cut: Primal and Sub primal Weights and Yields,” the round typically makes up 22% of the hot carcass weight. For an 880 – pound carcass, the round would be approximately 194 pounds. About 20 percent of that weight is made up of fat and bone. This leaves approximately 155 pounds of meat, including steaks, roasts, and ground product, that will be packaged for consumption.
Factors that affect yield of retail cuts include:
Carcass Fat – External carcass fat, or backfat, has the greatest impact on the percent of retail product from a carcass. As more fat is trimmed away from the retail cuts, less weight will be included in the final packaged product; thus, a lower percentage of retail cuts.
Carcass Muscularity – Superior carcass muscling can increase the yield of a carcass. Dairy – type animals with lower lean-to-bone ratios typically yield lower than beef type animals.
Cutting style or cutting directions given to the processor can affect carcass yield. For instance, the amount of bone-in versus boneless cuts, trimming of retail cuts and the percent of fat of the ground beef will affect retail yield.
Aging – the two major advantages of aging meat are improvement in tenderness and enhancement of a “beefy” flavor. A typical aging period of seven to fourteen days allows for tenderness development. Long term aging also can have a negative effect on carcass yield as it results in more weight loss from the carcass due to further moisture loss.
In summary, the amount of meat that is cut and wrapped for consumption will be much less than the live weight of the animal. A 1400-pound beef animal will yield a hot carcass weight of approximately 880 pounds. Once cooled, the carcass weight will be approximately 840 pounds. When deboned and trimmed, there will be approximately 570 pounds of product to fill your freezer.
It is important to remember that fat, bone and trim that is discarded from the carcass are not simply thrown away. These products are known as byproducts and can be used in various industries across the spectrum. From leather, pet food, and fertilizer to medical equipment, cosmetics and sporting equipment; the value of a harvested animal stretches far past your freezer.
It is important to understand that these numbers will vary based on many factors. Not all harvested animals weigh 1400 pounds. Some may be harvested at 1100 pounds and some at 1500+ pounds. Some animals may be dairy type and others may be beef type. Some may be grass finished and some may be grain finished. All these factors contribute to how much meat you take home.
When deciding to purchase an animal for harvest, keep in mind the space you have available for safe and effective storage. A quarter of beef takes an approximately 4.5 cu. ft. of chest freezer or a 5.5 cu. ft. upright freezer. A side (half), requires around 8 cu. ft. of space, while a whole beef will need 16 cu. ft.
To summarize: A 1,400-pound steer, one-half inch fat, average muscling, yields an 880-pound carcass. The 880-pound carcass yields approximately:
570 pounds boneless trimmed beef;
280 pounds fat trim and bone;
32 pounds of kidney, pelvic, and heart (KPH) fat, trim loss and carcass shrink.
Sources: Preparing to buy a Quarter of Beef, University of Minnesota Extension Beef Cuts Primal & Subprimal Weights and Yields Cattlemen’s Beef Board and National Cattlemen’s Beef Association. How Much Meat To Expect From a Beef Carcass University of Tennessee Extension Publication 1822 How Much Meat Can You Expect from a Fed Steer, South Dakota State University
Last week, Burger King released an ad toting the beloved (at least by me) Walmart yodel kid singing a song about cow farts releasing methane and leading to green house gas emission. This video quickly went viral and was met with a lot of jokes and some mixed reactions, from annoyance, to frustration, and honestly, a lot of confusion. Personally, I fell within the confused group. On one hand, I was glad that Burger King was still using and promoting real beef on their menu. On the other hand, the video seemed to provide a lot of misinformation that did not represent the beef industry well. I couldn’t be angry, but it certainly didn’t make me crave a Whopper!
Since then, Burger King has pulled the ad and has enlisted the help of Dr. Frank Mitloehner of UC Davis who specializes in air quality to ensure accuracy of their advertisements. I had the chance to hear Dr. Mitloehner speak at the International Livestock Congress at the Houston Livestock Show and Rodeo earlier this year and was so impressed by his presentation on the impact of livestock on the environment. Prior to the BK video release, Dr Mitloehner was active on social media sharing his insights and experience. Since the video dropped, more scientific information about the impact of livestock production on the environment, and people are listening.
It is encouraging to see a company like Burger King make the decision to work alongside the livestock industry to accurately promote a product. Admitting that their claims weren’t what they initially thought and being willing to stop the distribution of costly advertisements is a huge step. In the future, I hope to see more companies work with experts in animal science, whether that be farmers and ranchers, faculty at Universities, or others in the industry from the beginning to ensure factual advertising. This could go a long way to promote their product, accurately represent the ag industry and build consumer confidence in the food they eat.
About a month ago I defended my thesis, completing my M.S. degree in Animal Science at the University of Idaho. Following my defense, I packed up my apartment, loaded a U-Haul and hit the road back to South Dakota. The past few weeks I have been busy at home helping AI cattle, butchering a pig for our family, and finishing up my TA responsibilities. Although it has been so great to spend time at home with my family, it was a tough way to say goodbye to what had become a second home.
Two years ago, when I made the decision to move to Idaho, I was excited, but also nervous. I was excited for new adventures, but nervous about doing research and making friends. I had never worked in a lab before and my meat cutting skills were limited to what I had learned in the Intro to Meat Science course in my undergrad. On top of that, I didn’t know anyone in Idaho. I had met the professors I would work with during my two-day interview, but other than that, I didn’t know a soul. To say I was intimidated would be an understatement.
I knew that Idaho was the place I was meant to be. I had prayed a lot about this decision and after meeting with the professors I would work with, I knew the move was the right decision. Shortly after I moved to Idaho, I began to get to know the other graduate students and our undergraduate lab employees. As research projects ramped up, we spent more time on the kill floor, in the processing room, and in the chemistry lab. Although it took a while, I became more confident and comfortable with these processes.
I was busy preparing for my final defense when the quarantine began. At first, it was nice to be able to work from home. I had no excuse not to get my thesis finished and my presentation put together. Soon, however, I realized that this was how I was going to end my experience in Idaho. Graduation was cancelled, research projects were postponed, classes and my final defense was moved online. I had moved 1200+ miles from home, built a life in a new state, made friends that became family, and this is how I was to say goodbye.
During this time, a story that a pastor had shared with our congregation a few years prior kept coming to mind:
A man had a beautiful apple tree that he tenderly cared for. It was his pride and joy. One night, a storm came through and tore the tree from the ground. The next day, his neighbor came over and said, “You put so much time and effort into helping this tree grow, what are you going to do now?” The man with the tree turned to him and said, “I’m going to harvest the fruit, burn the tree, and move on.”
Harvest the fruit: My experience in Idaho was incredible. I am so proud of myself for stepping out of my comfort zone and moving somewhere new. I learned so much, was able to see some incredible sites, developed strong friendships and gained experiences that prepared me well for my future career.
Burn the tree: I was sad, but I let myself be. I had worked hard on my degree and was disappointed that this is how it was coming to an end. I let myself mourn the ending that I had planned for and wasn’t able to experience.
Move on: I am home now, and I am so thankful for the time I have been able to spend with my family. In a few weeks, I will begin my job at University of Nebraska-Lincoln working as an Extension Assistant Professor. Had the pandemic not occurred, I wouldn’t have been able to enjoy this time with my family and it would have been a quick transition from school into the new job. It is easy to be upset with all that has been happening in our world, but the time at home has been a major blessing.
There is a lot of sad things happening in our world, but I rest assured that it is in God’s control. For me, I know that although it may have come to a bittersweet end, I will forever be thankful for the time I had in Idaho. It is an experience I will not soon forget.
While at the University of Idaho, my research is focused on making beef more tender. To do this we evaluate enzymes, measure mechanical tenderness, and best of all, perform taste tests!
A lot of planning goes into performing a taste panel. It isn’t just simply cooking, cutting and serving steaks! Prior to performing the taste panels, product is labelled and randomly assorted. If we are looking at different treatments (ex. If the panel is looking at degrees of doneness, one treatment may be cooking steaks to well done, while another treatment is cooking to rare), the product is randomly distributed among the panelists. We don’t want one panelist to get 5 samples from the same treatment. Additionally, in the taste panels I performed, we assigned what order that the samples had to be eaten. This allows us to eliminate any bias or ‘sample fatigue’ of trying the same sample first every time. Sample fatigue may seem like a silly concept (who wouldn’t want more steak?), but it is necessary to limit the size and number of samples each panelist receives so they don’t become too full or exhaust their taste buds. We also serve unsalted crackers (boring, I know), and water with the samples so panelists can cleanse their palette between samples.
Along with the samples, panelists receive a questionnaire that has them rank each sample on a 1-10 scale based on tenderness, juiciness, flavor, and overall acceptability. They can also provide comments on what they really liked or disliked about the sample. This type of form gives us actual numbers to analyze for differences as well as provides some actual insight as to what the consumer actually thinks about the product.
Lab analysis is so important to meat science. Understanding what is actually happening within the meat itself is necessary to try to improve it. However, the most important aspect of researching food (in my opinion), is making sure that consumers are satisfied. We can develop the coolest technology to ‘improve’ the product, but if consumers are unhappy or don’t notice an improvement in the final product, it may not be worthwhile to implement. Because of this, taste panels are so important to develop methods to improve consumer satisfaction to drive the demand for high quality meat; keeping processors, producers and meat scientists in business.
My whole life I have been very fortunate to have home-raised beef in my freezer. It is not often that I have had to buy meat in the store, however, I do enjoy perusing the meat counter whenever I go grocery shopping to see what is available and how much it costs. Recently, I was shopping with a fellow meat science grad student when something in the meat counter caught our eye.
This picture shows two very different appearing steaks. The package on the right appears normal, being the typical bright cherry red color that we would expect to see. The package on the left, however, is a much darker color.
The condition of this product is known in the industry as being a “dark cutter.” As the name implies, it produces a very dark, unappealing product. It is caused by long term stress of the animal that can be influenced by genetics, environment, or management.
The simple explanation: Stress causes muscles to tense. When this happens all the energy in the muscles is used. When the animal is harvested, there is no energy left in the system to produce lactic acid and cause the meat to have a drop in pH. This leads to product that is darker in color, firm in texture due to holding water, and dry on the surface since all the moisture is held within the cut. For a more scientific explanation, read on. If this is enough, skip to the final paragraph.
To get scientific: muscle tissue stores energy in the form of glycogen. When we use our muscles, that glycogen is converted to lactic acid. (Think about when you try a new workout and are often sore the next day. This is due to a buildup of lactic acid in your muscles since you used the muscle’s energy.) When an animal is stressed for a long period of time, it uses up the glycogen within the system and depletes the lactic acid. (Think about when you’re stressed. Do you tense up? Do you clench your fists and your jaw? Your muscles are working. The same thing happens to livestock.)
When an animal is harvested, a lot of things happen as muscle is converted to meat. One of these things is a drop in pH. Living muscle tissue is very neutral, with a pH of approximately 7.0; whereas beef has a pH of approximated 5.6 (making it more acidic than living muscle). The drop in pH is caused by all of the glycogen that is left in the system at harvest being converted to lactic acid. If an animal has been stressed for a long period of time, there is no glycogen available in the system, and there won’t be any lactic acid to drop the pH. This causes the meat to have a very dark color and bind water tightly, creating a dry, tacky surface. This produces a product that is dark, firm and dry.
It is important to note, that this product is still safe to consume, but due to its high level of moisture, is often used in further processed products. Dark cutting beef is only found in approximately 1-2% of harvested cattle, often following severe changes in harsh weather. Producers do all they can to limit this occurrence by controlling the animal’s environment and stress level. Housing animals indoors, providing shade in the summer if housed outdoors, consistent feeding times, treating sickness, these are just a few practices that producers use to help mitigate stress of the animal. Animal care is a priority to producers and ensuring a safe, high quality product for consumers is their mission.
Have you ever seen the phrase “aged beef,” or “dry aged beef,”
in a menu or on an add and wondered what it really means? Aging is very important for tenderness
development in beef. It allows enzymes
that are naturally found in the meat to be active and breakdown protein that
leads to tenderness. Beef can be aged
for just a few days or up to a couple months before it is eaten. Outside of tenderness, aging can also be used
to help with flavor development.
Depending on how it is used, aging is not just an important science but
There are two types of aging that used in the beef industry:
wet aging and dry aging.
Wet aging is storing large cuts of meat in a sealed, vacuum
package bag under refrigerated temperatures, and is the most commonly used form
of aging in the industry. This method is
great because the packaging inhibits cross contamination with other products, controls
bacteria growth and retains the moisture from the product within the bag. Since the product doesn’t dry out, there is
very little waste once removed. Once
removed from the package, the product is further cut into steaks and roasts
before being sold to the end consumer.
Dry aging is storing the product without packaging in open
air. This method allows for mold growth
on the product as well high amounts of moisture loss. Although this may sound unappealing, the mold
growth allows for intense flavor development (example: one of the molds that is
commonly associated with blue cheese can be found on dry aged meat, giving the
meat a blue cheese like flavor). Once
the product is ready to be divided into retail cuts, the dried portion and mold
is cut off and discarded.
Dry aging is really where the art and science meet. Mold growth allows for flavor development,
but also has the potential for unsafe organisms to develop. Controlling temperature and airflow around
the product is key to limit dangerous growth.
Keeping these factors in mind account for the science, but how about the
art? Dry aging has not been extensively
studied, but has been done for ages. From
high end restaurants, to meat cellars, dry aging can be done in many different
places and conditions. Choosing the cut
of meat to age, length of time of aging, temperature control, etc., each person
doing the aging may have a different method to their madness. It’s an incredible collaboration of meat
science and culinary creativity.
Calcium and beef, not a combination that you hear paired
together very often, but it is a very important combo! Calcium is important in beef as it helps make
the meat tender. How does it do that you
may ask? Well let me tell you…
All muscle contains enzymes, called calpains, that breakdown
protein and are activated by calcium. These
enzymes are important during life because they help remove any weak, or injured
proteins in your muscles and let new, healthy protein be formed. Think about exercising. When you work out, your muscle fibers are injured
and the protein that makes them up is damaged.
Calpains help get rid of those injured proteins and let new, healthy
proteins take their place, helping your muscles gain strength.
Postmortem, when this muscle has been converted to meat,
those calpains are still active. The only
difference is that meat no longer has energy available to rebuild the muscle. Calpains are busy breaking apart the protein,
without new protein being formed. This continuous
breakdown is what causes meat to be tender. Think about eating a steak. Did your mouth
just water at the thought? If you have a
whole steak and try to just take a big bite without first cutting it, it will probably
be kind of tough to chew through. Cutting
the steak across the grain into bite-sized pieces makes it much more tender and
easier to chew. Calpains “cut” those
fibers and break them down, leading to a more tender product.
Calcium is important because it is responsible for
activating these enzymes. Without calcium,
there would be no need to age beef, because the enzymes responsible for
tenderness wouldn’t be active. The beef
we consume would be much tougher than what we know it to be today. It is so crazy to me that although beef isn’t
known to be a good source of calcium in our diet, it still requires calcium to
create a palatable product.
While at University of Idaho, my research has been focused
on finding a method to improve beef tenderness by activating calpains earlier
postmortem. Basically, I am trying to
find a way to make more calcium available to kick the enzymes into high
gear! This project has kept me busy in
the lab the past few months, but it has been so fun and exciting to see the
data pour in. I am continually amazed at
the amount of science that is involved in making a steak taste great, but it
has been so much fun to be a part of the research!
This weekend I was walking through the grocery store and stopped to browse the meat counter. My family raises cattle, so growing up we were fortunate to be able to fill our freezer with home-raised beef. I try to look at the meat counter whenever I get groceries to be aware of what products are offered, and how much they cost.
While perusing the beef section, a few packages of ground
beef caught my eye. There were three
options of ground beef, all selling for a different price and appearing to be a
different color. Today, I would like to
discuss the differences in fresh ground beef in terms of color and price.
Looking in the meat case, there were three options of fresh
93% XX-Lean Ground Beef ($5.08/lb)
85% X-Lean Ground Beef ($4.08/lb)
73% Regular Ground Beef ($2.98/lb)
When I first saw the product, the first thing that stood out
to me was the differences in color. As
you can see in the photo, there is quite a variation in redness between the XX-Lean
Ground Beef, and the Regular Ground Beef.
This difference is due to the fat content. The name of the product is describing the
percent of lean (actual meat, not fat), within the product. For example, the XX-Lean product was 93% lean
meat, and 7% fat; while the Regular product was 73% lean meat, and 27%
fat. Being that lean beef is a bright,
cherry red color, while fat is white, the different blend of meat/fat leads to color
The second thing that stuck out to me was the difference in
price. $2.10/pound is quite the
difference! Driving the price is once
again, the ratio of lean to fat. Although
fat has a lot of benefits in terms of flavor, juiciness, ease of cooking, etc.,
it is often seen as a waste product. If
you brown the ground beef, or make hamburger patties, a lot of that fat will cook
off and be discarded. Because of this,
it is seen as a lower value product. In
the 1.25 lb package of Regular ground beef, there is approximately 1/3 lb of
fat. In the XX-Lean package, there is
only about 0.08 lbs of fat, making it a higher value product.
Now, all three of these ground products are a good option to
take home, depending on what fits into your budget and how you intend to use
it. No matter what blend you choose,
remember that beef is an excellent source of protein and 9 other essential nutrients. It’s a healthy option that will leave your
family full and satisfied.
If you come across anything interesting at the meat counter
and have questions, please send them my way!
If I don’t know the answer, I’d love to do some digging to help find it!