Interpretive Summary: Evaluation of marbling and enhancement's abilities to compensate for reduced beef palatability at elevated degrees of doneness.
By: Thomas Powell
The generally accepted theory has been that higher levels of marbling in meat lessen the negative impact of increasing degrees of final doneness on the ultimate palatability of cooked meat. A recent study at Kansas State University published in the Journal of Animal Science adds a degree of specificity to that theory by taking a comprehensive look at the interactive effects of marbling level and degree of doneness (DOD) on the juiciness, flavor and tenderness components of palatability.
The research team pulled strip loins from beef carcasses selected across the marbling levels of Prime, Top Choice, Low Choice, and Select and aged them in vacuum packaging for 21 days. A fifth treatment was created by enhancing Select loins at 7 days of aging to 110% of raw weight with a water, salt, and alkaline phosphate solution. Steaks cut from the loins after 21 days of aging were sliced, frozen and later cooked to one of five DOD: very rare, rare, medium-rare, medium, well done, or very well done. Consumer and trained sensory panels evaluated aspects of juiciness, tenderness and flavor in the cooked steaks. Objective measurements included Warner-Bratzler shear force (WBSF), slice shear force (SSF), pressed juice percentage (PSP), and raw and cooked proximate analysis.
The key finding in this study is that juiciness is the only component of sensory palatability that was protected by higher marbling from some of the adverse effects of high DOD. The findings revealed that for each quality treatment, a DOD threshold exists where there is a significant reduction in the percentage of steaks rated acceptable for juiciness. The trained panel results indicated that the higher degrees of doneness had a less detrimental effect on juiciness in the Prime and enhanced Select samples. Both consumer and trained panel observations showed that there is no added benefit to increased marbling on flavor when cooked to higher DOD. Tenderness results from sensory panels and objective methods did not consistently show an interaction between marbling and DOD.
Two other noteworthy findings include: first, that the enhanced Select treatment performed on par with the Prime samples in many measurements of palatability, and, second, that the strongest objective predictor of sensory palatability was the relationship between the combination of cooked fat and moisture content and sensory juiciness scores. The article also includes an in-depth comparative analysis of the findings from several prior studies.
To view the full article, visit the Journal of Animal Science.