Consumer sensory evaluation and chemical composition of beef gluteus medius and triceps brachii steaks from cattle finished on forage or concentrate diets

The objective of this study was to assess the impact of cattle finishing diet and muscle type on meat quality. Consumer sensory response, proximate composition, Warner–Bratzler shear force (WBSF), fatty acid composition, and volatile compounds were assessed from the gluteus medius (GM) and triceps brachii (TB) muscles of cattle (n = 6 per diet) which were grain-finished (USUGrain) on conventional feedlot or 2 forage diets, a perennial legume, birdsfoot trefoil-fin-ished (USUBFT; Lotus corniculatus), and grass-finished (USUGrass; Bromus riparius). Diet had an interacting effect with muscle for all sensory attributes (P ≤ 0.002), except aroma and flavor (P ≥ 0.078). In forage-finished beef, tenderness, fattiness, overall liking, and WBSF tenderness of GM was greater (P < 0.05) than TB, whereas for USUGrain, the tenderness, fattiness, overall liking, and WBSF tenderness of both muscles were similar (P > 0.05) but the juiciness of TB was more liked than USUGrain GM (P < 0.05). The juiciness of forage-finished beef did not differ (P > 0.05) between GM and TB. Lower (P < 0.05) intramuscular fat (IMF) percent was determined for USUGrass beef in comparison with USUGrain beef. The IMF percent of USUBFT beef was similar (P > 0.05) to both USUGrass and USUGrain beef. However, IMF percent was not impacted by muscle type (P = 0.092). The ratio of n-6:n-3 fatty acids was affected by muscle dependent on diet (P = 0.016). The ratio of n-6:n-3 fatty acids was affected by the interaction of muscle × diet (P = 0.016). Between forage diets (USUGrass and USUBFT), n-6:n-3 ratios were similar (P > 0.05) between GM and TB, whereas within USUGrain, the GM was greater (P < 0.05) than the TB. Cumulative MUFA was greater (P < 0.05) in USUGrain compared with both USUGrass and USUBFT, which were similar (P > 0.05). Strecker aldehydes, ketones, pyrazines, and methional were affected (P ≤ 0.036) by muscle and found to have a greater concentration in GM compared with TB. Overall, consumers determined that USUGrain GM and TB had similar (P > 0.05) quality ratings. However, within forage-finished beef, the GM was perceived more frequently (P < 0.05) to be of premium quality and the forage-finished TB was more frequently (P < 0.05) rated as having unsatisfactory quality. These findings were in agreement with ratings of tenderness and overall liking. Therefore, in the context of our consumer group grilled GM and TB steaks, grain-finished beef provided more uniform quality and eating experience compared with forage-finished beef.