title: Color stability of semitendinosus, semimembranosus, and biceps femoris steaks packaged in a high-oxygen modified atmosphere.
abstract: The objectives of this study were to evaluate visual and chemical attributes of beefsteaks from various USDA quality grades and muscles packaged in high-oxygen (80% O2/20% CO2) modified-atmosphere packaging (MAP). A total of nine carcasses were selected to represent Select (n = 3), low Choice (n = 3), and high Choice (n = 3) USDA quality grades. The semimembranosus (SM), semitendinosus (ST), and biceps femoris (BF) muscles were removed from each carcass and allotted to two packaging types (MAP or polyvinyl chloride over-wrap) and were displayed for up to 10 d, with evaluation on d 1, 3, 5, 7, and 10. Fifty-four steaks were evaluated on each day by a five-member trained panel for visual color (lean color and discoloration) and were also analyzed with a Minolta Chroma Meter CR-310 for L* and a* values (lightness and redness, respectively). Chemical properties measured included percentage of metmyoglobin formation and fat content. Visual color scores did not differ (P > 0.05) at d 1 and 3 with respect to all quality grades, but decreased after d 3, with a greater reduction (P < 0.05) in high Choice steaks for both lean color and discoloration. The low Choice steaks packaged in MAP displayedhigher (P < 0.05) lean color scores and less (P < 0.05) discoloration at d 7 and 10 than did Select and high Choice steaks. Redness (a*) values also decreased (P < 0.05) after d 3, whereas (lightness) L* values declined (P < 0.05) from d 1 to 5. The high Choice steaks had higher (P < 0.05) metmyoglobin content than low Choice and Select steaks, but packaging had no effect (P > 0.05) on metmyoglobin content. Muscle type did affect metmyoglobin content; however, the metmyoglobin content of the SM was greatest (P < 0.05), followed by the BF, with the ST having the lowest (P < 0.05) metmyoglobin formation. Results indicate that low Choice steaks react the best in MAP, and the ST maintained greater storage characteristics regardless of quality grade or packaging.
authors.affiliation: Department of Animal Sciences, University of Kentucky, Lexington 40546, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Behrends
authors.forename: W B
authors.initials: WB
authors.lastname: Mikel
authors.forename: C L
authors.initials: CL
authors.lastname: Armstrong
authors.forename: M C
authors.initials: MC
authors.lastname: Newman
mesh_terms: D000818:Animals; D002417:Cattle; D018857:Food Packaging / Q000379:methods*; D008460:Meat / Q000145:classification / Q000592:standards*; D008786:Metmyoglobin / Q000032:analysis; D018482:Muscle, Skeletal / Q000378:metabolism*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000494:pharmacology*; D010858:Pigmentation; D011786:Quality Control; D013997:Time Factors; D014481:United States; D016885:United States Department of Agriculture
chemical_list: D008786:Metmyoglobin; D010100:Oxygen