The objectives of this study were to evaluate the extent marbling compensates for reduced beef palatability at elevated degrees of doneness and to determine the relationship of residual moisture and fat in cooked steaks to beef palatability, specifically beef juiciness. Paired strip loins (IMPS # 180) were collected to equally represent five quality treatments [Prime, Top Choice (modest and moderate marbling), Low Choice, Select, and Select Enhanced (110% of raw weight)]. Steaks were grouped into sets of three consecutively cut steaks and randomly assigned a degree of doneness (DOD): very-rare (VR; 55 °C), rare (R; 60 °C), medium-rare (MR; 63 °C), medium (M; 71 °C), well done (WD; 77 °C), or very well done (VWD; 82 °C). Samples were subjected to consumer and trained sensory evaluation, Warner-Braztler shear force (WBSF), slice shear force (SSF), pressed juice percentage (PJP) evaluation, and raw and cooked proximate analysis. There were no (P > 0.05) quality treatment × DOD interactions for consumer sensory ratings, indicating increased DOD had the same negative impact regardless of marbling level. There was a quality treatment × DOD interaction (P < 0.05) for the percentage of steaks rated acceptable by consumers for juiciness. Increased marbling modified the point in which steaks became unacceptable for juiciness. Similarly, there was a quality treatment × DOD interaction (P < 0.05) for trained juiciness ratings. When cooked to MR and lower, Prime was rated only 8% to 18% higher (P < 0.05) than Select for trained juiciness ratings, but was rated 38% to 123% higher (P < 0.05) than Select when cooked to M and higher. Besides cooking loss, combined cooked moisture and fat percentage was more highly associated (P < 0.01) to consumer juiciness (r = 0.69) and trained initial (r = 0.84) and sustained (r = 0.85) juiciness ratings than all other objective evaluations. Using regression analyses, cooked moisture and fat percentages, alone, were poor indicators of consumer and trained juiciness ratings. However, when combined, the regression equations explained 45%, 74%, and 69% of the variation in consumer, trained initial, and trained sustained juiciness ratings, respectively. These results indicate that increased marbling levels only offer "insurance" for juiciness of steaks that are cooked to high degrees of doneness, but not for other palatability traits. Additionally, cooked residual moisture and fat percentages, when combined, are a good indicator of sensory juiciness ratings.

The objective of this study was to evaluate the impact of USDA quality grade on beef eating quality of top sirloin steaks when cooked to multiple degrees of doneness (DOD). Beef top sirloin butts (N = 60; 15/quality grade) were collected to equally represent 4 quality grades [Prime, Top Choice (modest00 to moderate100), Low Choice, and Select]. Steaks were assigned to 1 of 3 DOD: rare (60°C), medium (71°C), and well-done (77°C). Steaks were allocated to either consumer sensory analysis, trained sensory analysis, fat and moisture analysis, or Warner-Bratzler shear force (WBSF). There were no interactions (P > 0.05) for all consumer ratings of palatability traits, indicating increases in DOD had the same impact across all quality grades. Prime steaks had greater (P < 0.05) juiciness ratings than all other quality grades, except for Top Choice. As DOD increased, consumer ratings and the percentage of steaks rated acceptable for each palatability trait decreased (P < 0.05; rare > medium > well-done). There was a quality grade × DOD interaction (P < 0.05) for trained sensory panel juiciness scores. When cooked to medium, Prime and Top Choice steaks were rated higher (P < 0.05) for juiciness than Low Choice and Select steaks, while there were no differences at all other DOD. Similar to consumer ratings, trained panel ratings of tenderness decreased (P < 0.05) as DOD increased (rare > medium > well-done). Lastly, there was no quality grade by DOD interaction (P > 0.05) for Warner-Bratzler shear force. These results indicate that regardless of the DOD top sirloin steaks are cooked to, quality grade had minimal impact on palatability. Therefore, it is unnecessary for consumers, retailers, and foodservice to pay premium prices for higher quality top sirloin steaks, as the same eating experience will be provided.

The objective of this study was to determine the impact on beef palatability perceptions when consumers with varying degree of doneness (DOD) preferences are served steaks cooked to multiple DOD. Paired Low Choice strip loin steaks were randomly assigned to a DOD of either rare (60°C), medium-rare (63°C), medium (71°C), medium-well (74°C), or well-done (77°C). Consumer panelists were prescreened for DOD preference (rare, medium, or well-done) prior to sensory panels and were assigned to panels based on their DOD preference. In the first round of testing, consumers were served 1 sample from each of the 5 DOD under low-intensity red incandescent light to mask any DOD differences among samples. In round 2 of testing, consumers were fed the paired samples cooked to the same DOD under white incandescent lights. There were no (P > 0.05) consumer DOD preference × steak DOD interactions or consumer DOD preference effects for tenderness, juiciness, and flavor ratings when steaks were evaluated under both lighting types. Within the white-lighting testing, there was a consumer DOD preference × steak DOD interaction (P < 0.05) for overall acceptability. Consumers who preferred steaks cooked to well-done reported no differences (P > 0.05) in overall palatability among DOD under white-lighting, whereas consumers who preferred steaks cooked to rare and medium rated steaks lower (P < 0.05) for overall palatability as DOD increased. Regardless of DOD preference, consumer sensory ratings decreased (P < 0.05) when steaks were cooked above the consumer’s preferred DOD; whereas sensory ratings improved (P < 0.05) when steaks were served below the consumers’ preferences. These results indicate that overcooking steaks has the greatest negative impact on beef palatability perception and thus, foodservice should err on the side of undercooking steaks to preserve, and potentially improve, eating satisfaction.

The objective was to characterize ham and loin quality of carcasses ranging from 78 to 145 kg (average ∼119 kg). Hot carcass weight (HCW), back fat depth, and loin depth was measured on 666 carcasses. Loin pH, instrumental and visual color and iodine value of clear plate fat (all 3 layers) was measured on approximately 90% of the population. Quality measurements of the ham, 14 d aged loin and chop, and loin chop shear force (SSF) were evaluated on approximately 30% of the population. Myosin heavy chain fiber type determination was completed on 49 carcasses. Slopes of regression lines and coefficients of determination between HCW and quality traits were calculated using the REG procedure in SAS and considered significantly different from 0 at P ≤ 0.05. As HCW increased, loin depth (b1 = 0.2496, P < 0.0001), back fat depth (b1 = 0.1374, P < 0.0001), loin weight (b1 = 0.0345, P < 0.0001), and ham weight (b1 = 0.1044, P < 0.0001) increased. Estimated lean (b1 = –0.0751, P < 0.0001) and iodine value (b1 = –0.0922, P < 0.0001) decreased as HCW increased, where HCW accounted for 24% (R2 = 0.24) of the variation in estimated lean and 7% (R2 = 0.07) of the variation in iodine value. However, HCW did not explain variation in ham quality traits (P > 0.15) and did not explain more than 1% (R2 ≤ 0.01) of the variation in 1 d loin color or pH. Loins from heavier carcasses were more tender (decreased SSF; b1 = –0.0674, P < 0.0001), although HCW only explained 9% of the variation in SSF. Hot carcass weight did not alter (P > 0.22) muscle fiber type percentage or area. These results suggest that increasing HCW to an average of 119 kg did not compromise pork quality.

The objective of this study was to assess consumer and chef perceptions and knowledge of beef degrees of doneness (DOD) as well as to measure the changes in cooked color over time related to DOD. Steaks from strip loins (M. longissimus lumborum) from each of 5 quality treatments were used for this study. Steaks were cooked to an endpoint temperature of either very-rare (54°C), rare (60°C), medium-rare (63°C), medium (71°C), well-done (77°C), or very well-done (82°C). L*, a*, and b* were evaluated at 0, 1, 2, 3, 6, 9, and 12 min post-cutting and digital pictures were taken immediately on an internal surface of the steak. Digital surveys for the evaluation of the images of the cooked steaks were created for consumers and chefs. There were time × DOD interactions (P < 0.05) for L*, a*, and b* values. For very-rare, rare, medium-rare, and medium, a* values increased (P < 0.05) over time. For L*, well-done and very well-done steaks became darker (P < 0.05) and very-rare, rare, and medium-rare steaks became lighter (P < 0.05) over time. Surveys indicated consumers determine DOD when cooking beef in their home primarily by using color, whereas chefs primarily use touch to determine DOD. There were no quality grade effects (P > 0.05) for DOD responses for steak pictures evaluated by consumers or chefs. Consumers identified the DOD of cooked steaks as the DOD that corresponds to published end-point temperatures 27 to 35% of the time. Chefs typically identified the DOD as 1 DOD higher than which the steaks were cooked for steaks cooked to medium or less and 1 DOD lower for steaks cooked to well-done and higher. This indicates differences exist in the perceptions of DOD between culinary professionals and consumers, and may contribute to decreased consumer satisfaction when ordering steaks in a restaurant.