{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/56591"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/56591","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Biochemical Basis of Fresh Ham Color Development","abstract":"Commercial hams display variation in color uniformity across the cut surface, especially the semimembranosus (SM) muscle. This variation in fresh ham color, or two-toning, persists through further processing and contributes to production of a less desirable end product. In an attempt to understand the underlying source of this color variation, we evaluated the differences in muscle fiber-type composition and glycolytic metabolism in the SM muscle of fresh hams differing in color uniformity. Fifty-eight fresh SM muscles, ranging in color, were selected at 24 h postmortem and each partitioned into four distinct regions and three color classes based on color uniformity in the caudal region. The L* (lightness) values were greatest and a* (redness) values lowest in the most caudal portions of the muscle. The caudal portion also exhibited the lowest ultimate pH (P < 0.0001), lowest myoglobin (P < 0.05), greatest glycolytic potential (GP) (P < 0.0001) and the lowest myosin heavy chain type I isoform (P < 0.0001) abundance of all regions in 'normal' colored hams. After segregating based on L* values, the caudal region had identical pH, GP, LDH, and MyHC-I, despite significant differences in L* (P < 0.0001). These data show the most caudal aspects of the SM are indeed more prone to adverse postmortem metabolism and suggest that inherent differences in muscles of the ham may make some areas of the ham more vulnerable to temperature abuse during harvesting.","abstract_html":"Commercial hams display variation in color uniformity across the cut surface, especially the semimembranosus (SM) muscle. This variation in fresh ham color, or two-toning, persists through further processing and contributes to production of a less desirable end product. In an attempt to understand the underlying source of this color variation, we evaluated the differences in muscle fiber-type composition and glycolytic metabolism in the SM muscle of fresh hams differing in color uniformity. Fifty-eight fresh SM muscles, ranging in color, were selected at 24 h postmortem and each partitioned into four distinct regions and three color classes based on color uniformity in the caudal region. The L* (lightness) values were greatest and a* (redness) values lowest in the most caudal portions of the muscle. The caudal portion also exhibited the lowest ultimate pH (P &lt; 0.0001), lowest myoglobin (P &lt; 0.05), greatest glycolytic potential (GP) (P &lt; 0.0001) and the lowest myosin heavy chain type I isoform (P &lt; 0.0001) abundance of all regions in &#x27;normal&#x27; colored hams. After segregating based on L* values, the caudal region had identical pH, GP, LDH, and MyHC-I, despite significant differences in L* (P &lt; 0.0001). These data show the most caudal aspects of the SM are indeed more prone to adverse postmortem metabolism and suggest that inherent differences in muscles of the ham may make some areas of the ham more vulnerable to temperature abuse during harvesting.","abstract_has_math":false,"creators":["Stufft, Kristen Marie"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Animal and Poultry Sciences","degree_department":"Animal and Poultry Sciences","school":null,"contributors":[],"advisors":[],"committee_chairs":["Gerrard, David E."],"committee_members":["Johnson, Sally E.","Mills, Edward William"],"year":2015,"date_issued":"2015-09-14","date_published":"2015-09-14","updated_at":"2026-07-22T22:19:16Z","subjects":["pork quality","ham quality","muscle metabolism","meat color"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:6154"],"render_values":[{"text":"vt_gsexam:6154","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/56591","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Gerrard, David E."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Johnson, Sally E.","Mills, Edward William"]},{"key":"dc:contributor.department","label":"Department","values":["Animal and Poultry Sciences"]},{"key":"dc:creator","label":"Author","values":["Stufft, Kristen Marie"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2015-09-18T20:07:26Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2015-09-18T20:07:26Z"]},{"key":"dc:date.issued","label":"Date","values":["2015-09-14"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Animal and Poultry Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["pork quality","ham quality","muscle metabolism","meat color"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:6154"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/56591"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Commercial hams display variation in color uniformity across the cut surface, especially the semimembranosus (SM) muscle. This variation in fresh ham color, or two-toning, persists through further processing and contributes to production of a less desirable end product. In an attempt to understand the underlying source of this color variation, we evaluated the differences in muscle fiber-type composition and glycolytic metabolism in the SM muscle of fresh hams differing in color uniformity. Fifty-eight fresh SM muscles, ranging in color, were selected at 24 h postmortem and each partitioned into four distinct regions and three color classes based on color uniformity in the caudal region. The L* (lightness) values were greatest and a* (redness) values lowest in the most caudal portions of the muscle. The caudal portion also exhibited the lowest ultimate pH (P < 0.0001), lowest myoglobin (P < 0.05), greatest glycolytic potential (GP) (P < 0.0001) and the lowest myosin heavy chain type I isoform (P < 0.0001) abundance of all regions in 'normal' colored hams. After segregating based on L* values, the caudal region had identical pH, GP, LDH, and MyHC-I, despite significant differences in L* (P < 0.0001). These data show the most caudal aspects of the SM are indeed more prone to adverse postmortem metabolism and suggest that inherent differences in muscles of the ham may make some areas of the ham more vulnerable to temperature abuse during harvesting."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["ETD"]},{"key":"dc:title","label":"Title","values":["Biochemical Basis of Fresh Ham Color Development"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Gerrard, David E."],"dc:contributor.committeemember":["Johnson, Sally E.","Mills, Edward William"],"dc:contributor.department":["Animal and Poultry Sciences"],"dc:creator":["Stufft, Kristen Marie"],"dc:date.accessioned":["2015-09-18T20:07:26Z"],"dc:date.available":["2015-09-18T20:07:26Z"],"dc:date.issued":["2015-09-14"],"dc:description.abstract":["Commercial hams display variation in color uniformity across the cut surface, especially the semimembranosus (SM) muscle. This variation in fresh ham color, or two-toning, persists through further processing and contributes to production of a less desirable end product. In an attempt to understand the underlying source of this color variation, we evaluated the differences in muscle fiber-type composition and glycolytic metabolism in the SM muscle of fresh hams differing in color uniformity. Fifty-eight fresh SM muscles, ranging in color, were selected at 24 h postmortem and each partitioned into four distinct regions and three color classes based on color uniformity in the caudal region. The L* (lightness) values were greatest and a* (redness) values lowest in the most caudal portions of the muscle. The caudal portion also exhibited the lowest ultimate pH (P < 0.0001), lowest myoglobin (P < 0.05), greatest glycolytic potential (GP) (P < 0.0001) and the lowest myosin heavy chain type I isoform (P < 0.0001) abundance of all regions in 'normal' colored hams. After segregating based on L* values, the caudal region had identical pH, GP, LDH, and MyHC-I, despite significant differences in L* (P < 0.0001). These data show the most caudal aspects of the SM are indeed more prone to adverse postmortem metabolism and suggest that inherent differences in muscles of the ham may make some areas of the ham more vulnerable to temperature abuse during harvesting."],"dc:description.degree":["Master of Science"],"dc:format.medium":["ETD"],"dc:identifier.other":["vt_gsexam:6154"],"dc:identifier.uri":["http://hdl.handle.net/10919/56591"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["pork quality","ham quality","muscle metabolism","meat color"],"dc:title":["Biochemical Basis of Fresh Ham Color Development"],"dc:type":["Thesis"],"thesis:degree_discipline":["Animal and Poultry Sciences"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:16Z"}