High Stress Steaks

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.

The picture on the left shows product that would be considered a
“dark cutter.”

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.

The Art and Science of Aging Beef

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 an art.

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.

These are strip loins that were used for a research project in our lab this semester. The bright red loins were wet aged. Notice that they do not have the same “crust” like the others that would need to be removed before steaks are cut. The other loins were dry aged for 45 days.

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?

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!

The Science Behind a Steak

Did you know that every food and drink item that you can buy in a grocery store has been through various forms of scientific testing? Whether it be for pathogens, allergens, microbial growth, flavor development, ingredient use, sensory appeal, the list goes on and on, there is a lot of science that goes into the food we eat!

The same goes for the products that you can purchase at the meat counter. Now, when I say that there is science in your steak, I don’t mean that it has been chemically altered. I mean that there has been significant testing put into place to help improve that piece of meat to provide a great eating experience and safe product for you and your family. One of those tests is Warner-Bratzler Shear Force (WBSF).

Although a long name, WBSF is a simple concept. Imagine biting into a big, juicy steak and having one of these two thoughts:

“This is so tender, it just melts in my mouth,” or “This is so tough, I feel like I’m chewing on rubber!”

Sound familiar? These two thoughts are describing the tenderness of the steak. WBSF is a measurement of tenderness. To complete this test, steaks are cooked and cores (basically bite sized pieces) are removed. The cores are then cut with a machine that measures how many kilograms of pressure it takes to cut through the piece (the force it takes to shear the core, hence the name). This represents how much pressure you would have to use to chew through the product. The lower the WBSF value, the more tender the steak. Using this information, we can find different things that can improve tenderness, whether that be a production method (think the animal’s environment it is raised in or what it is fed), a processing method (how long the product was aged, how the meat was cut, etc.) or cooking method (rare vs. well-done).

WBSF is often used alongside taste panels. It is helpful to use WBSF as it gives a definite number without being influenced by personal preference. However, taste panels are necessary because even if a machine tells us it should taste good, it’s people who need to enjoy it.

Step 1: Cook the steaks to a consistent temperature.
Step 2: Remove cores (bite size pieces), try to get a representative group from the whole steak.
Step 3: Shear the core and get the final measurement of force.

For those of you who are new to The Meating Room and haven’t read my bio, I am currently pursuing my master’s degree in meat science. Last week, our lab group spent three days running WBSF analysis. Three days, 230 steaks, 1,400+ cores to cut, all to try to find a method to improve steak tenderness and consistency for the end consumer.

This is just a tiny fragment of the science that goes into producing great tasting steak. As I continue with my project, I hope to share more of the work we are doing in the lab and to give you an insight into what a “meat scientist” really does!

Meatless Monday

Recently, a private University in my home state of South Dakota announced that they will be implementing a “Meatless Monday” program. This is supported by their claims that plant based proteins offer more nutritive value than meat and that meat is generally more expensive than plant-based proteins. I’d like to take a little time today to talk about these two points and see how they really add up.

Plant based proteins offer more nutritive value than meat.

The South Dakota Beef Industry Council shares this graphic and I think it is really eye opening. I’ll admit that it is easy to assume that plant -based proteins will offer more protein per calorie than meat. But in all reality, when looking at the quantity of these products that need to be consumed to reach the protein level provided by one serving of beef, we quickly see that it is not the case.

Per 25 g protein:

Quinoa: 666 calories

Peanut butter: 613 calories

Beef: 173 calories

In addition to being low calorie, that one serving of beef provides 10 essential nutrients- Protein, Iron, Choline, Selenium, Vitamin B, Zinc, Phosphorus, Niacin, Riboflavin. It offers an incredible amount of nutritive value!

Meat is generally more expensive than plant-based proteins.

In addition to an animal science degree, I also received a bachelor’s degree in agricultural business. The business side of me always perks up when I hear claims of ‘more expensive’. It is time to crunch some numbers.

Image and Price from Walmart.com

I have heard a lot of talk recently about the Beyond Burger, so I thought that would be a great example to look at. When initially comparing the Beyond Burger pricing vs. the ground beef patties, it appears to be less expensive. However, looking further we see that on a per pound basis, the Beyond Beef patties are almost twice the price of both ground beef patties (the difference in the patties is the fat content. 80% lean vs. 93% lean. The 93% lean is more expensive on a per pound basis because it has a lower fat content). Don’t let the face value of a product lead you astray. It is important to judge actual economic value of a product not on the simple dollar value it receives, but price per pound basis. It is amazing how much of a difference that can make!

One other thing that I think is interesting to point out about the Beyond Burger is the ingredient list. Consumers continually demand a high quality product with a clean label. Looking at the Beyond Burger ingredient list we see that it contains over 15 ingredients!

“Water, pea protein isolate*, expeller-pressed canola oil, refined coconut oil, rice protein, natural flavors, mung bean protein, methylcellulose, potato starch, contains 1% or less: apple extract, salt, potassium chloride, vinegar, lemon juice concentrate, sunflower lecithin, beet juice extract, pomegranate fruit powder, lycopene color (from tomato).”

Now let’s compare that ingredient list to that of the ground beef patties:

“Ground Beef and Natural Flavorings.”

Two ingredients! That’s it! The Food Safety Inspection Service allows spices and seasonings such as black pepper, onion powder, and garlic to be defined as natural flavorings. It is a simple product that offers so much to the consumer.

Simply put, animal based proteins are a relatively low calorie, low cost option that are supported by a clean label. Protein takes up a large portion of the grocery budget. We all want to feed our families a high quality product. When thinking about it in that sense, meat offers the most bang for your buck. For that reason, I plan to keep meat in my diet on Mondays, and every other day of the week!

How much meat do cattle provide?

Have you ever wondered how many pounds of beef that cattle provide? It’s a great question, and something that livestock producers and packers care a lot about:

More muscle (what becomes meat) per animal = More pounds of saleable product

So, how much meat do we get?

The average market weight (body weight of the animal the day that it ‘goes to market’, ie: when it is harvested) of beef cattle is around 1,400 pounds. As the animal goes through the harvest process, the head, hide, blood, viscera (internal organs and digestive system), and hooves are removed. At this point, what is left is referred to as a carcass.

From here, we can calculate the dressing percent of the carcass. Dressing percent is equal to the carcass weight, divided by the live weight of the animal. For cattle, this value is typically around 63%, but can vary depending on how much muscle and fat the carcass has, as well as what gender and breed the animal was. A high dressing percent means that more product is available to use.

At this point, the carcass is fabricated. This means that it is cut into large, wholesale cuts, and then into retail cuts (what you buy at the store: steaks, roasts, etc). In the agriculture industry, the amount of actual saleable product is known as the amount of yield from a carcass. This is also referred to as the percent of boneless, closely trimmed (much of the extra fat removed), retail cuts (yes, some cuts have bones that remain with the product, but many are removed). The percent yield in beef animals is typically around 65%.

So lets take a look at an example:

Say a steer has a market weight of 1350 lbs. We expect that animal to produce around an 850 lb carcass. From here, we cut the carcass into saleable product and remove excess fat and bones. We are left with approximately 553 lbs of meat.

Now, it is important to remember that all the product that is removed before we reach our final retail cuts is able to be used! Almost nothing from the animal is thrown out. Here are just a few examples of products besides meat that cattle provide us:

Hide: leather for furniture, car seats and clothing.
Bones: Used to make gelatin, used in things like jello and gummy bears.
Fat: Also known as tallow, used in production of biodiesel and in some cosmetics.
Intestines: Cleaned and sanitized and then used for casing for sausages and other processed products.

I hope this post helps answers your question about how much meat that one animal can provide us, but don’t forget, they offer us so much more!

Let’s Talk Quality

Last week we talked about meat inspection, which is based on wholesomeness and safety. Quality grade on the other hand, is focused on determining palatability; determining how tender, how juicy, and how flavorful you can expect the meat to be. While inspection is a legal requirement for all meat that will be sold and is supported by tax dollars, quality grade is optional and paid for by the packer. Whether or not quality grade is used depends on the goals of each operation.

Quality grade in beef is based on two factors:

Maturity: In order to qualify for the highest level of quality grade, the animal must be under 30 months of age. This is determined by dentition (how many teeth they have). As an animal gets older, the meat is known to become more tough and have a poorer color which is often seen as a turn off to consumers. Since the packer can choose whether to use grading, carcasses that are classified as older may be determined as a “No Roll”, meaning they won’t receive a ‘rolled on’ stamp for their quality grade. Much of the meat from this carcass will be ground for hamburger or used for jerky products, where the quality grade is not as important, rather than being used for steaks. *Important note: Even though it may not receive a quality grade, the carcass is still inspected to ensure that it is safe to eat. *

Marbling: The most important factor for determining quality is the level of marbling, or intramuscular fat (Fat that actually lies within the muscle). While cooking, this fat will melt into the meat, making it juicy, tender and very flavorful.

At the plant, the animal is ‘ribbed’, exposing the loin muscle. Here, USDA representatives from the Agricultural Marketing Service use a camera to determine the grade. Grades can range from:

Prime: Young carcass, VERY high level of marbling. Meat should be very tender, juicy and flavorful due to the high levels of fat.
Choice: Young carcass, Small to moderate level of marbling. This is the grade that is most often seen in the industry and ensures a tasty, tender product.
Select: Slight level of marbling but still from a young animal. Meat in this category may still be very tender but will be less juicy than the grades above.
Standard: Young animal but very, very little marbling.
Cutter, utility, commercial: Low grades often from older animals, 100% safe to eat but may not make a tasty steak. It is rare to see these quality grades because carcasses that would fall into this section are often not graded.

The photo on the left shows a carcass with a select grade, while the one on the right shows a choice grade. Notice the differences in marbling, or specks of fat that lie within the muscle.

To wrap this up, inspection is a legal requirement to ensure meat safety. Quality grade is optional, but often used by packers as a method to inform consumers how palatable a product will be. Quality grade is determined primarily by how much marbling is in the loin muscle and signifies how tender, juicy and flavorful the meat will be!