Aging increases lightness of grass-fed beef

Grass-fed beef is becoming increasingly popular and is expected to be a $14 billion industry by 2024. Even so, grass-fed beef is typically darker in appearance than that of conventional grain-fed beef. Aging has been shown to improve lean color (L*, a*) of dark-cutting beef however little work has focused on aging as it relates to improving the lean color of grass-fed beef. Therefore, the aim of this study was to evaluate the effect of dry aging on grass-fed beef compared to varying lengths of grain-feeding. Thirty commercial Angus crossbred steers were randomly assigned to either pasture finishing (CON), short (SF), or long fed (LF) programs. The SF and LF treatments ranged from 90 to 114 d (average: 98 d) and 118 to 134 d (average: 125 d) on ad libitum high concentrate feeding, respectively. Cattle were randomly identified from each treatment group and harvested over a consecutive 3-wk span. Carcass evaluation and longissimus lumborum samples were collected 24 h postmortem. Carcasses were aged for 21 d, and steaks were collected on 1-, 3-, 7-, 10-, 14-, and 21-d postharvest, and objective color was evaluated following 1 h bloom. Our data show color (L*, a*, b*) was improved with aging regardless of treatment. However, grass-fed (CON) showed the greatest improvement in both lightness (L*) and redness (a*) ultimately making grass-fed comparable to that of grain-fed beef by day 21. These data argue that dry-aging grass-fed beef improves color development similar to that of grain-fed beef.