Postmortem aging time and marbling class effects on flavor of three muscles from beef top loin and top sirloin subprimals

Authors: King, David - Andy; Shackelford, Steven; Wheeler, Tommy

Submitted to: Meat and Muscle Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/12/2020
Publication Date: 3/12/2021
Citation: King, D.A., Shackelford, S.D., Wheeler, T.L. 2021. Postmortem aging time and marbling class effects on flavor of three muscles from beef top loin and top sirloin subprimals. Meat and Muscle Biology. 5(1). https://doi.org/10.22175/mmb.10939.
DOI: https://doi.org/10.22175/mmb.10939

Interpretive Summary: Ensuring beef tenderness is a key factor in providing positive eating experiences to consumers. The most common method for ensuring beef tenderness is postmortem aging at refrigerated temperatures. However, little is known about the effects of prolonged postmortem aging on flavor of beef products. This study was conducted to examine the effects of extended postmortem aging times on beef top loin and top sirloin steak flavor profiles for the lowest one-sixth of the U.S. Choice or the upper half of the U.S. Select grades. These steaks were evaluated by a sensory panel trained to detect the intensity of 31 flavor attributes in beef. Of these attributes, very few were affected by either marbling class or aging time. Differences in these traits that reached statistical significance were small in magnitude and likely of little practical importance. However, substantial variation did occur in flavor attributes among the steak types. Production lot (feedlot pen) was most related to this variation, particularly in off-flavors such as metallic, barnyard, and rancid flavor attributes. Thus, these data suggest that antemortem factors associated with beef production may contribute to the incidence of undesirable flavor of beef. Moreover, these data indicate that prolonged aging can be utilized to ensure beef tenderness without negative consequences on beef flavor.

Technical Abstract: This study evaluated postmortem aging time and marbling class effects on flavor attributes of longissimus lumborum, gluteus medius, and biceps femoris steaks. Carcasses selected to have Lower Small (Small00 to Small49; n = 50) or Upper Slight (Slight50 to Slight99; n = 50) marbling were assigned to aging treatments (14, 21, 28, or 35 d) in an incomplete block arrangement.A trained sensory panel evaluated longissimus lumborum, gluteus medius, and biceps femoris steaks for tenderness, juiciness, and 31 flavor notes. Tenderness increases with aging time were linear (P <0.001) in longissimus lumborum and gluteus medius steaks and quadratic (P=0.001) in biceps femoris steaks. Aging response of rancid flavor in longissimus lumborum steaks was cubic (P = 0.01), whereas the aging response of bloody/serumy flavor in biceps femoris steaks was quadratic (P = 0.03). Compared with Upper Slight marbling, carcasses with Lower Small marbling produced longissimus lumborum steaks with greater (P < 0.01) beef flavor and lesser (P = 0.001) bitter flavor, gluteus medius steaks with greater (P = 0.05) brown/roasted flavor, and biceps femoris steaks with greater (P = 0.02) fat-like flavor, although differences were small. Principal component analysis indicated that bloody/serumy, sour, metallic, and bitter flavor attributes were the strongest contributors to a factor explaining 38% of longissimus lumborum flavor variation. Barnyard, bitter, sour, rancid, and bloody/serumy were the greatest contributors to a principal component explaining 41% of gluteus medius flavor. Barnyard, rancid, sour, bloody/serumy, and bitter were contributors to a component explaining 63% of biceps femoris sirloin cap flavor variance. Sample score plots indicated that neither aging time nor marbling class was associated with principal components and identified production lot as contributing to principal components explaining flavor variation in all 3 muscles. Results indicate that, in strip loin and top sirloin subprimals from carcasses with Upper Slight and Lower Small marbling scores, aging time and marbling class had little impact on beef flavor. Thus, increased aging times could be used to enhance tenderness with no adverse effects on other important palatability attributes.