title: Turnover of carbon, nitrogen, and sulfur in bovine longissimus dorsi and psoas major muscles: Implications for isotopic authentication of meat.
abstract: Stable isotope ratio analysis of light elements (including C, N, and S) is a powerful tool for inferring the production and geographic origins of animals. The objectives of this research were to quantify experimentally the isotopic turnover of C, N, and S in bovine skeletal muscle (LM and psoas major) and to assess the implications of the turnover for meat authentication. The diets of groups (n = 10 each) of beef cattle were switched from a control diet containing barley and unlabelled urea to an experimental diet containing maize, (15)N-labeled urea, and seaweed for periods of up to 168 d preslaughter. The feeding of the experimental diet was clearly reflected by the delta(13)C, delta(15)N, and delta(34)S values of the LM and psoas major muscles, but isotopic equilibrium was not reached in either muscle for C, N, or S after 168 d of feeding the experimental diet. The slow turnover in skeletal muscle was reflected by the C and N half-lives of 151 and 157 d for LM and 134 and 145 d for psoas major, respectively, and by an S half-life of 219 d in LM. It is concluded that the turnover of light elements (C, N, and S) in bovine skeletal muscles is a slow process; therefore, skeletal muscles contain isotopic information on dietary inputs integrated over a long period of time (months to years).
authors.affiliation: UCD School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland. bojlul.bahar@ucd.ie
authors.forename: B
authors.initials: B
authors.lastname: Bahar
authors.forename: A P
authors.initials: AP
authors.lastname: Moloney
authors.forename: F J
authors.initials: FJ
authors.lastname: Monahan
authors.forename: S M
authors.initials: SM
authors.lastname: Harrison
authors.forename: A
authors.initials: A
authors.lastname: Zazzo
authors.forename: C M
authors.initials: CM
authors.lastname: Scrimgeour
authors.forename: I S
authors.initials: IS
authors.lastname: Begley
authors.forename: O
authors.initials: O
authors.lastname: Schmidt
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D002244:Carbon / Q000378:metabolism; D002247:Carbon Isotopes / Q000032:analysis; D002417:Cattle / Q000254:growth & development / Q000378:metabolism*; D004032:Diet / Q000662:veterinary; D008297:Male; D008460:Meat / Q000592:standards*; D018482:Muscle, Skeletal / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D009587:Nitrogen Isotopes / Q000032:analysis; D016658:Psoas Muscles / Q000378:metabolism*; D013455:Sulfur / Q000378:metabolism; D013460:Sulfur Isotopes / Q000032:analysis
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D013460:Sulfur Isotopes; D013455:Sulfur; D002244:Carbon; D009584:Nitrogen