Beef flavor has been defined as an important component of beef demand. Beef flavor, however, is not a single attribute, but it is composed of multiple attributes that can be dynamic. The beef industry took the first big step in addressing beef flavor by funding the development of the beef flavor lexicon that identified major and minor beef flavor components. The beef industry cannot develop systems for identifying beef flavor if it does not know what “beef flavor” is or how the human senses perceives beef flavor. Now that the beef flavor lexicon has been developed, researchers are working to understand what compounds are responsible for each attribute in the lexicon. After understanding what chemical compounds are responsible for specific beef flavor attributes, this information can be used to control, mask, enhance or reduce specific flavor compounds to manage and improve beef flavor. While this research is on-going, one of the big questions that still has not been answered is “which beef flavor attributes are positive and which attributes are negative for beef consumers?” While consumer perceptions are variable, some attributes may be positive to one consumer, but negative to another consumer, it is important to understand the effect of specific beef flavor attributes on consumer attitudes across consumer segments.
The objective of this study was to determine consumer attitudes toward beef flavor in steaks of different quality grades, grilling temperatures and thicknesses.
Strip Loins from 32 random carcasses were selected in a commercial processing facility from USDA Select (n=16) and upper two-thirds USDA Choice (n=16) carcasses. Vacuum-packaged Strip Loins were transported to the Texas A&M University, Rosenthal Meat Technology Center and stored at 4°C for 14 days post-processing. Because steak thickness was a primary treatment, the Strip Loins were placed in the freezer after aging to allow uniform and precise cutting of steaks on the band saw. After intact Strip Loins were frozen, one of the Loins from each animal was divided into 12 portions for 2 cooking temps (high temperature = 450°F/232°C or low temperature = 350°F/177°C) and 2 steak thicknesses (thin steaks = 0.5-inch and thick steaks = 1.5-inches). For each analysis, individual steaks were selected and thawed in refrigerated (4°C) storage for 12 to 24 hours. Steaks for all cooked analyses were placed on the grill, turned when the internal temperature reached 37.7°C (100°F) and removed when the internal temperature reached 71°C (160°F, medium degree of doneness).
Beef flavor attributes were measured using the beef lexicon (0 = none and 15 = extremely intense) by a trained sensory panel. Furthermore, consumers (80 per city) were randomly selected in 4 cities (Olathe, KS; State College, PA; Griffin, GA; and Portland, OR) so that geographical areas were representing the Midwest, the East coast, Southeast and the West coast. In each city, 4 consumer sessions with approximately 20 consumers per session were conducted. After completion of each consumer session, 4 to 5 consumers (n = 20 consumers per city) were asked to participate in one-on-one exit interviews to determine their attitudes toward beef and beef flavor.
Volatiles were captured from the same steaks evaluated by the consumer panelists in State College, PA. After samples were prepared for consumers, approximately seventy-five grams of 0.5-inch beef cubes were placed in foil with a tag separated from the meat samples. Volatiles were evaluated using the Aroma Trax gas chromatograph/mass spectrophotometer system with dual sniff ports for characterization of aromatics. Raw meat pH, fatty acid composition, myoglobin content, fatty acids and non-heme iron content were determined from each raw muscle.
USDA Choice steaks tended to be rated higher in beef ID and brown/roasted descriptors compared to USDA Select steaks. Beef ID and brown/roasted ratings were the highest for 1.5-inch steaks cooked at 350 degrees. Fat-like, umami and sweet descriptors were the lowest for 1.5-inch steaks cooked at 450 degrees. Consumer liking scores were not affected by quality grade in this study. Similar to the trained sensory panel findings, consumers rated 1.5-inch steaks cooked at 450 degrees lowest in overall like, flavor like, beef flavor like, grill flavor like and juiciness like. Nearly 220 volatile aroma chemicals were generated from the steaks in this study. As might be expected, the chemicals associated with steak browning were highest in the thicker steaks and those cooked at 450 degrees compared to the thinner steaks cooked at the lower 350 degrees. In fact, about one-third of all of the variation in beef ID trained panel scores can be accounted for by the cook time before flipping and grill temperature. These data indicate that the development of beefy, brown/roasted flavors can best be accomplished by long cooking times at moderate cooking temperatures.
Thick-cut steaks cooked at high temperatures may not be ideal for the development of beefy, grilled flavors that are considered the trademarks of good steak flavor. Cooking protocols should be developed that allow for longer cooking times at moderate temperatures. High-temperature cooking of thick steaks were scored significantly lower than those cooked at moderate temperatures.
Table 1. Simple correlation coefficients (r; higher values [+ or -] indicate variables are more related) among cooking parameters and trained sensory panel descriptive attributes.
|
Beef ID |
Brown/ Roasted |
Bloody/ Serumy |
Fat-like |
Metallic |
Livery |
Umami |
Initial grill temp |
0.096 |
0.224 |
-0.408 |
-0.133 |
0.001 |
-0.167 |
-0.214 |
Steak surface temp at flip |
0.239 |
0.241 |
-0.284 |
-0.089 |
0.013 |
-0.079 |
-0.046 |
Grill temp at flip |
0.102 |
0.184 |
-0.322 |
-0.109 |
-0.030 |
-0.082 |
-0.135 |
Grill time - 1st side |
0.519 |
0.459 |
-0.147 |
-0.093 |
0.182 |
-0.166 |
0.127 |
Grill time - 2nd side |
0.360 |
0.379 |
-0.180 |
-0.185 |
0.138 |
-0.032 |
0.006 |
Total grill time |
0.503 |
0.481 |
-0.189 |
-0.162 |
0.183 |
-0.111 |
0.074 |
Final steak surface temp |
0.307 |
0.367 |
-0.435 |
-0.180 |
0.059 |
-0.086 |
-0.118 |
Final grill temp |
0.163 |
0.253 |
-0.444 |
-0.205 |
0.063 |
-0.199 |
-0.215 |
Cook loss, % |
0.154 |
0.184 |
-0.072 |
-0.232 |
0.087 |
-0.147 |
-0.062 |
Photos from the lab.