Background 

Flavor is an important attribute that greatly impacts beef eating experience. Beef flavor is perceived by the senses in response to flavor compounds, which develop during cooking. The development of cooked beef flavor compounds is driven by chemical reactions between precursor compounds present in raw beef (Mottram, 1998).  

Traditionally flavor has been considered one of the three major attributes of beef palatability, along with tenderness and juiciness (Morgan et al., 1991; Neely et al, 1998). Assessment of flavor by consumers has traditionally been based on acceptability or preference (AMSA, 1995). It is, however, known that flavor is made up of several attributes including: basic tastes, flavor aromatics, and feeling (Adhikari et al., 2011).  

USDA quality grade has been shown to affect palatability ratings assessed by consumer and trained panelists (Smith et al., 1985; Savell et al., 1987; Lorenzen et al., 1999; Lorenzen et al., 2003; O’Quinn et al., 2011). Additionally, a descriptive beef lexicon has been developed which may quantify several flavor attributes affected by USDA quality grade (Adhikari et al., 2011).  

It was the objectives of this study to explore the effect of USDA quality grade on consumer palatability ratings, descriptive flavor attributes, and relationships of flavor descriptors with consumer ratings.  

Methodology 

Experimental design:  

Completely randomized design with 3 treatments (USDA Prime, Low Choice, and Standard) with strip loin serving (n = 8 per quality grade treatment) as experimental unit (n = 24)  

Consumer Sensory Evaluation:  

Consumer panelists (n = 108) evaluated a steak representing each treatment in a randomized order using a 100-mm continuous line scale for flavor, tenderness, juiciness, and overall liking. On the scale, 0 was verbally anchored as not tender, not juicy, dislike flavor extremely, and dislike overall extremely. Similarly, 100 was verbally anchored as very tender, very juicy, like flavor extremely, and like overall extremely. In addition, each consumer was asked to rate flavor as acceptable or unacceptable. Consumers also rated flavor intensity by an 8-point hedonic scale and were asked if off-flavors were detected.  

Trained Flavor Descriptive Analysis:  

Six highly trained panelists from the Sensory Analysis Center at Kansas State University (Manhattan, KS) participated in the trained panel. The beef flavor lexicon developed at K-State in conjunction with Texas A&M University (Adhikari et al., 2011), and funded by the Beef Checkoff was used by the panel.  

Findings 

Results indicate that USDA quality grade impacts consumer and trained descriptive palatability ratings. Increases in quality grade yield greater consumer ratings for tenderness, juiciness, flavor, and overall liking. Flavor descriptor ratings, for positive flavor attributes (Beef identity, Initial flavor impact and fat-like), increase with quality grade, while negative flavor descriptors are inversely correlated with quality grade. Standard steaks were characterized by attributes such as liver-like and serumy. The descriptive sensory work presented here was correlated with consumer and instrumental measures carried out at TTU and it was found that flavor was highly correlated with overall liking. Relationships between flavor descriptors and consumer ratings reveal consumers are adequately evaluating juiciness independent of flavor and tenderness. Flavor ratings by consumers seem to be impacted by off-flavors and brown/roasted flavors independent of tenderness. 

Implications 

Subtle differences in flavor attributes can collectively impact consumer preference. With significant improvements in beef tenderness over recent history flavor has become a highly valued beef characteristic to consumers. Continued exploration of beef flavor is required in order to discover novel management and intervention practices to enhance flavor.