Repository logo

Browsing by Author "Emerson, Mallory R., author"

Now showing 1 - 1 of 1
  • Thumbnail Image
    ItemOpen Access
    Relationships between USDA camera-based quality grades and beef sensory attributes
    (Colorado State University. Libraries, 2011) Emerson, Mallory R., author; Woerner, Dale R., advisor; Tatum, J. Daryl, advisor; Belk, Keith E., committee member; Pendell, Dustin L., committee member
    This study quantified relationships of recently adopted camera-based USDA beef quality grades to LM sensory attributes and shear force. Heifer and steer carcasses (n = 718, all A-maturity) were selected at beef processing plants in CO, KS, NE, and TX, using marbling scores determined by on-line camera grading systems, to represent 7 marbling degrees: Traces (TR), Slight (SL), Small (SM), Modest (MT), Moderate (MD), Slightly Abundant (SA), and Moderately Abundant (MA). Strip loin steaks were obtained from both sides of each carcass and aged for 14 d. One steak was used to obtain Warner-Bratzler shear force (WBSF) and slice shear force (SSF) measurements; the other steak was evaluated by a trained sensory panel for juiciness, tenderness, detectable levels of several flavors (meaty/brothy, buttery/beef fat, bloody/serumy, livery/organy, and grassy), and overall sensory experience (negative vs. positive). Camera marbling score explained 45, 40, 32, 71, and 61% of the variation in panel ratings for juiciness, tenderness, meaty/brothy flavor intensity, buttery/beef fat flavor intensity, and overall sensory experience, respectively. Increased degree of marbling resulted in steaks having greater (P < 0.001) juiciness, tenderness, meaty/brothy flavor intensity, and buttery/beef fat flavor intensity. The likelihood of a steak delivering a positive sensory experience also became greater (P < 0.001) as degree of marbling increased (MA = SA > MD = MT > SM > SL > TR). Nearly all (98 to 99%) of the steaks with MA and SA marbling, and most (between 80 and 90%) of the steaks with MD and MT marbling received positive ratings for overall sensory experience compared with 62% of the SM steaks, 29% of the SL steaks and 15% of the TR steaks. Steaks produced by steers had lower (P < 0.05) WBSF and SSF values and were generally rated as more tender by sensory panelists than steaks produced by heifers, but the effect of sex on panel tenderness was significant only within the TR category. Comparison of 2 methods for determining camera-based quality grades (i.e., use of original camera grade lines, based on marbling assessments of USDA grading experts vs. use of adopted camera grade lines, based on marbling assessments of field graders) showed that both methods of grade placement effectively stratified carcasses into grades that differed (P < 0.05) with respect to steak juiciness, tenderness, and flavor, with little discernible difference between methods.