title: Influence of supplemental vitamin C on postmortem protein degradation and fatty acid profiles of the longissimus thoracis of steers fed varying concentrations of dietary sulfur.
abstract: The objective was to examine the effects of supplemental vitamin C (VC) on postmortem protein degradation and fatty acid profiles of cattle receiving varying concentrations of dietary sulfur (S). A longissimus muscle was collected from 120 Angus-cross steers assigned to a 3 × 2 factorial, evaluating three concentrations of dietary S (0.22, 0.34, and 0.55%) and two concentrations of supplemental VC (0 or 10 g h(-1)d(-1)). Increasing dietary S and VC supplementation (P<0.001) increased the percent polyunsaturated fatty acids of steaks. Addition of VC tended to increase (P = 0.09) both Fe and 2-thiobarbituric acid content of longissimus thoracis. Increasing S increased (P = 0.03) the proportion of 80-kDa subunit of μ-calpain. Addition of VC within the high S treatment increased (P = 0.05) the abundance of 76-kDa subunit of μ-calpain. Increasing S decreased troponin T degradation (P = 0.07) and protein carbonylation (P<0.01). Supplemental VC appears to alleviate negative effects of high S on autolysis of μ-calpain and protein degradation.
authors.affiliation: Department of Animal Science and Interdepartmental Graduate Program in Nutritional Sciences, Iowa State University, Ames, IA 50011, United States.
authors.forename: Danielle J
authors.initials: DJ
authors.lastname: Pogge
authors.forename: Steven M
authors.initials: SM
authors.lastname: Lonergan
authors.forename: Stephanie L
authors.initials: SL
authors.lastname: Hansen
mesh_terms: D000273:Adipose Tissue / Q000737:chemistry; D000821:Animal Feed / Q000032:analysis; D000818:Animals; D001205:Ascorbic Acid / Q000008:administration & dosage*; D002154:Calpain / Q000378:metabolism; D002417:Cattle; D004032:Diet / Q000662:veterinary*; D019587:Dietary Supplements; D005227:Fatty Acids / Q000032:analysis; D005231:Fatty Acids, Unsaturated / Q000032:analysis; D050356:Lipid Metabolism; D008297:Male; D008460:Meat / Q000032:analysis; D018482:Muscle, Skeletal / Q000737:chemistry*; D011180:Postmortem Changes; D050050:Protein Carbonylation; D013455:Sulfur / Q000008:administration & dosage*; D020107:Troponin T / Q000378:metabolism
chemical_list: D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D020107:Troponin T; D013455:Sulfur; D002154:Calpain; C449002:mu-calpain; D001205:Ascorbic Acid
keywords: Cattle; Fatty acid; Sulfur; Vitamin C; μ-Calpain