Bone and Subcutaneous Fat Influence on Yield, Physicochemical Traits, and Color Stability of Dry-Aged Loin From Grass-Fed Nellore Bulls

Abstract

The objective of the current study was to evaluate the influence of bone and subcutaneous fat on yield, physicochemical traits, and color stability of dry-aged beef from grass-fed Nellore bulls. Paired bone-in loins (from the 10th thoracic vertebra to 6th lumbar vertebra) from 8 carcasses were collected and cut in half, and the sections from each carcass were assigned to 4 treatments (n = 8): bone-in with subcutaneous fat, bone-in without subcutaneous fat, boneless with subcutaneous fat, and boneless without subcutaneous fat. Loin sections were dry-aged for 21 d, at 2°C and 70% relative humidity. After dry aging, the half-loins were weighed, trimmed, and weighed again to determine the evaporation loss, trimming loss, and yield. Additionally, water activity, pH, thiobarbituric acid-reactive substances, moisture content, cooking loss, pressed juice percentage, Warner-Bratzler shear force, and color stability (during 9 d of display) were analyzed. No interactions (P > 0.05) between bone and subcutaneous fat were found for evaporation and trimming loss, yield, and physicochemical traits. The treatments did not affect Warner-Bratzler shear force, pressed juice percentage, thiobarbituric acid-reactive sub-stances, and pH values (P > 0.05). Regarding color stability, there was a bone-by-time interaction (P < 0.05) for a* and b* parameters. Boneless treatments showed higher a* and b* values (P < 0.05) than bone-in treatments, after 6 and 7 d of display, respectively. Bone-in treatments and treatments with subcutaneous fat had lower evaporation and trimming loss and higher yield compared to boneless treatments and treatments without subcutaneous fat, respectively (P < 0.05). Therefore, although bone-in treatments showed lower color stability, bone and subcutaneous fat were considered important factors to the dry-aging process, as both resulted in a greater yield over dry-aged product that had bone and/or fat removed, without compromising other physicochemical traits of dry-aged beef from grass-fed Nellore bulls.