Date of Graduation
Master of Science in Animal Science (MS)
Jason K. Apple
Casey M. Owens-Hanning
Second Committee Member
Steven C. Seideman
In two experiments, dark-cutting (DC) beef strip loins were used to test the effects of citric acid-enhancement pH on visual and instrumental color of fresh and cooked steaks. Dark cutting and normal pH strip loin were injected to 111% of raw product weight with pH 3.5, 4.0, 4.5, or 5.0 solutions by mixing citric acid in either 0.05% phosphate solution or tap water (Exp 1), or with pH 2.0, 2.5, 3.0, and 3.5 solutions made by mixing citric acid in either a 0.5% orthophosphate solution (PO4) or a 0.5% tripolyphosphate solution (STP) (Exp2). Loin sections were cut into 2.5-cm-thick steaks and assigned to either simulated retail display for five days or cooked. Post-enhancement pH of enhanced DC steaks did not (P ≥ 0.180) differ from that of non-enhanced DC steaks, regardless of solution pH (Exp 1); however, decreased linearly (P < 0.001) as solution pH decreased from 3.5 to 2.0, and the proportions of free and bound moisture of DC steaks enhanced with pH 2.5 solution were comparable (P ≥ 0.141) to that of CH (Exp 2). On d 1 and 3 of display, fresh color scores of enhanced DC steaks were greater (P < 0.001) than untreated DC (Exp 1), but color scores of CH steaks were greater (P < 0.001) than enhanced DC steaks (Exp 1 and 2). Conversely, in experiment 1, degree of doneness scores increased linearly (indicating greater doneness; P = 0.032) as solution pH increased from 3.5 to 5.0, and steaks enhanced with pH 4.0 and 4.5 solutions received lower (more red; quadratic, P = 0.012) cooked color scores than non-enhanced DC steaks, but neither score was comparable (P < 0.001) to those for CH steaks. While in experiment 2 enhancing DC sections with pH 2.5 solutions produced cooked color and degree of doneness scores that were similar (P ≥ 0.113) to non-enhanced CH steaks. Thus, enhancement with pH 2.5 citric acid solutions can effectively eliminate the persistent red cooked color typically associated with DC beef; however, citric acid enhancement failed to improve the fresh color of DC beef comparable to that of CH beef.
Stackhouse, Ryan, "Effects of Enhancement Solution pH on Fresh and Cooked Color of Dark-Cutting Beef" (2016). Theses and Dissertations. 1752.