Recently, Jerrad Legako, a professor with Texas Tech University's Department of Animal and Food Sciences, was in the spotlight in a new story by Bob Holmes of Smithsonian Magazine. Here's part of the conversation dealing with scientifically informed grilling.

Summer has arrived, and it's time to fire up the backyard grill. So, what's the best way to grill that steak? Science has some answers.

Meat scientists (many of them, unsurprisingly, in Texas) have spent whole careers studying how to produce the tenderest, most flavorful beef possible. Much of what they've learned holds lessons only for cattle producers and processors, but a few of their findings can guide backyard grillmasters in their choice of meat and details of the grilling process.

Let's start with the choice of meat. Every experienced cook knows that the lightly used muscles of the loin, along the backbone, have less connective tissue and thus give tenderer results than the hard-working muscles of the leg. And they know to look for steaks with lots of marbling, the fat deposits between muscle fibers that are a sign of high-quality meat.

From a flavor perspective, in fact, the differences between one steak and the next are mostly a matter of fat content: the amount of marbling and the composition of the fatty acid subunits of the fat molecules. Premium cuts like ribeye have more marbling and are also richer in oleic acid, an especially tasty fatty acid — “the one fatty acid that frequently correlates with positive eating experience,” said Jerrad Legako, a professor of meat science and graduate student coordinator with Texas Tech University's Department of Animal and Food Sciences. Sirloin, in contrast, has less oleic acid and more fatty acid types that can yield less appealing, fishy flavor hints during cooking.

That fatty acid difference also plays out in a big decision that consumers make when they buy a steak: grain-fed or grass-fed beef? Grain-fed cattle — animals that live their final months in a feedlot eating a diet rich in corn and soybeans — have meat that's higher in oleic acid. Animals that spend their whole life grazing on pasture have a higher proportion of omega-3 fatty acids, polyunsaturated fatty acids that break down into smaller molecules with fishy and gamy flavors. 

The biggest influence on the final flavor of that steak, though, is how you cook it. Flavorwise, cooking meat accomplishes two things. First, the heat of the grill breaks the meat's fatty acids into smaller molecules that are more volatile — that is, more likely to become airborne. These volatiles are responsible for the steak's aroma, which accounts for the majority of its flavor. Molecules called aldehydes, ketones and alcohols among that breakdown mix are what we perceive as distinctively beefy.

The second way that cooking builds flavor is through browning, a process that chemists call the Maillard reaction. This is a fantastically complex process in which amino acids and traces of sugars in the meat react at high temperatures to kick off a cascade of chemical changes that result in many different volatile end products. Most important of these are molecules called pyrazines and furans, which contribute the roasty, nutty flavors that steak aficionados crave. 

The longer and hotter the cooking, the deeper into the Maillard reaction you go and the more of these desirable end products you get — until eventually, the meat starts to char, producing undesirable bitter, burnt flavors. The challenge for the grillmaster is to achieve the ideal level of Maillard products at the moment the meat reaches the desired degree of doneness. Here, there are three variables to play with: temperature, time and the thickness of the steak.

Legako was honored earlier this year was the recipient of the 2021 Texas Tech Chancellor's Council Distinguished Research Award. The award is the most prestigious honor given to faculty members throughout the Texas Tech University System. Legako's research and teaching specialization is in the area of meat science, and his research program primarily focuses upon pre- and post-harvest factors which influence beef quality. 

His program is differentiated from others based on his usage of analytical chemistry to explore beef flavor character and beef flavor development. Some of the specific factors being explored in Legako's research group include how animal diet, management, genetics, post-mortem aging, packaging and cooking influence beef flavor. 

Thus far in his academic career, Legako has served as an investigator on research projects totaling more than $4.9 million. Results from these research efforts have been presented in 55 peer-reviewed journal articles, 113 refereed abstracts, 11 proceedings papers, one invited white paper, and o4e co-authored book chapter.

CONTACT: Michael Orth, chairman, Department of Animal and Food Sciences, College of Agricultural Sciences & Natural Resources, Texas Tech University at (806) 834-5653 or michael.orth@ttu.edu

0628NM21 / Editor's Note: For the full-text version of the Smithsonian Magazine story, please click here.