| Summary: | The objective of this study was to evaluate the effects of marbling texture on muscle fiber morphometrics, adipocyte cross-sectional area, perimysial thickness, collagen solubility, and thermal transition temperature of perimysial collagen of beef strip loin steaks from 3 marbling scores. Beef strip loins ( = 117) were selected from three marbling scores [Top Choice (Modest – Moderate marbling), Low Choice (Small marbling), and Select (Slight marbling)] to equally represent 3 different marbling texture groups: fine, medium, and coarse, via visual appraisal. There were no marbling texture × marbling score interactions for all traits evaluated. Marbling texture impacted ( < 0.05) adipocyte cross-sectional area, where coarse steaks displayed larger adipocytes in comparison to fine marbled steaks, but medium marbled steaks were similar ( > 0.05) to both coarse and fine marbled steaks for the same trait. However, marbling texture did not impact ( > 0.05) perimysial thickness. Marbling texture did not affect collagen traits, as no differences ( > 0.05) were found among marbling texture treatments for soluble collagen, insoluble collagen, and total collagen concentrations. Furthermore, all marbling texture groups (fine, medium, and coarse) were similar ( > 0.05) for the peak thermal transition phase of the perimysial fraction of collagen. Marbling score affected adipocyte size, as Top Choice and Low Choice possessed larger ( < 0.05) adipocytes than Select steaks. There were no differences ( > 0.05) among marbling scores for fiber type; nor were differences found among marbling textures or marbling scores for fiber cross-sectional area. These results indicate that marbling texture does not contribute to differences in collagen characteristics or fiber cross-sectional area that may impact eating quality of beef strip loin steaks.
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