CORRELATIONS AND PREDICTION EQUATIONS FOR FATTY ACIDS AND SENSORY CHARACTERISTICS OF BEEF LONGISSIMUS RIB STEAKS FROM FORAGE-FED CATTLE AND RETAIL USDA CHOICE AND SELECT RIB STEAKS

ABSTRACT

Rib steaks (n = 52) from forage-fed cattle and United States Department of Agriculture Choice and Select rib steaks obtained from area supermarkets were utilized to determine correlations between fatty acids and sensory characteristics, to develop prediction models for sensory characteristics, and to determine correlations among fatty acids. The beef/brothy and beef fat sensory characteristics were positively correlated (P < 0.05) with 16:0, 16:1cis-9 and 18:1, and negatively correlated (P < 0.05) with 15:0, α-18:3, 20:4, 20:5, 22:5 and 22:6. The grassy sensory characteristic was positively correlated (P < 0.05) with 15:0, 16:1trans-9, 18:0, 18:2cis-9,trans-11 (conjugated linoleic acid [CLA]), α-18:3, 20:5, 22:5 and 22:6. Regression utilizing stepwise selection to develop prediction equations for sensory characteristics indicated that the beef/brothy sensory characteristic was best predicted (P < 0.05) by the single fatty acid 20:5, with this fatty acid explaining 40% of the variation. CLA and α-18:3 were utilized in the model that best predicted (P < 0.05) milky/oily flavor, with these two fatty acids explaining 31% of the variation. These results indicate that CLA and the 20- and 22-carbon polyunsaturates have large roles in influencing flavor, causing increases in grassy and milky/oily flavor or decreasing beef/brothy flavor.

PRACTICAL APPLICATIONS

With the increase in concentrate feed costs, it has become more important to finish cattle on alternate feedstuffs, particularly forage. However, shifting cattle from concentrate to forage finishing diets may impart different sensory attributes of the beef produced. Therefore, it would be advantageous to be able to predict palatability characteristics such as beef flavor in order to correctly segregate beef into markets that seek and accept different sensory attributes. Results from this study would allow beef to be identified from its fatty acid profile as forage finished or grain finished in sensory characteristics and therefore targeted to the appropriate markets. Furthermore, with these results, it may be possible to produce and correctly classify beef from forage-finished diets that may exhibit affinities to deposition of fatty acids more closely associated with grain-finished beef, and therefore fit into those markets.