Evaluation of marbling and enhancement’s abilities to compensate for reduced beef palatability at elevated degrees of doneness1

Abstract

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.

Evaluation of Beef Top Sirloin Steaks of Four Quality Grades Cooked to Three Degrees of Doneness

“…This compensation for decreased palatability that marbling provides is commonly known as the "insurance theory" (Smith and Carpenter, 1974;Savell and Cross, 1988). To date, only 1 study has thoroughly evaluated the interaction between marbling and DOD in depth through sensory evaluation (Drey et al, 2019). In our study, no quality grade × DOD interactions were present in all consumer sensory rating data.…”

“…Previous literature has established that as DOD increases, tenderness, juiciness, flavor, and overall acceptability of steaks decrease linearly (Parrish et al, 1973;Akinwunmi et al, 1993;O'Quinn et al, 2018). More notably, recent studies have demonstrated enhancement and higher degrees of marbling can compensate for detrimental effects on palatability that are associated with increasing DOD in the LL (Lucherk et al, 2016;Drey et al, 2019). This compensation for decreased palatability that marbling provides is commonly known as the "insurance theory" (Smith and Carpenter, 1974;Savell and Cross, 1988).…”

“…The impact marbling level has on beef palatability has been thoroughly evaluated in previous literature (Parrish et al, 1973;Smith et al, 1985;Akinwunmi et al, 1993;O'Quinn et al, 2012;Emerson et al, 2013;Corbin et al, 2015;McKillip et al, 2017). Studies have noted a linear increase in tenderness, juiciness, flavor, and overall acceptability of beef steaks as marbling level increases (Emerson et al, 2013;O'Quinn et al, 2018;Drey et al, 2019); however, many of these studies have only evaluated marbling level within the LL. Cuts from the strip loin are moderate in connective tissue, with greater amounts of connective tissue typically found within muscles of locomotion, such as the chuck and round (McKeith et al, 1985).…”

“…In our study, no quality grade × DOD interactions were present in all consumer sensory rating data. Studies by Lucherk et al (2016), McKillip et al (2017), and Drey et al (2019 have also noted the lack of this interaction in consumer ratings; however, these authors have strictly evaluated the LL. Consumer sensory and acceptability ratings in our study are also inconsistent with this theory, as the impact of increased DOD on juiciness, tenderness, flavor, and overall like ratings were independent of quality grade.…”

The effects of the LIPEX finishing diet regimen on pork quality, fatty acid profile, palatability, and color stability12

“… Huff-Lonergan et al (2002) established marbling was correlated to both subjective and objective pork palatability measures. Drey et al (2019) demonstrated the effect marbling has on improved consumer and trained panel tenderness, juiciness, and flavor ratings. Juarez et al (2011) found pork chops from barrows were 1.2 points greater in flavor than gilts.…”