Effects of collagen content, fiber alignment, storage and heating on cooking characteristics, dimensional changes and microstructure of restructured beef
Hsu, Kanghuan M.
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Studies were conducted to determine the effects of collagen level, fiber alignment, frozen storage and oven temperature on cooking characteristics and the dimensional and structural changes of restructured beef steaks. Three replicates of high (HC) and low collagen (LC) raw materials similar in proximate composition, salt content, pH and physical measurements but different in total collagen were manufactured and stored for either 40, 85 or 130 days before cooking by broiling or roasting. HC steaks tended to require less time for heat to penetrate than LC steaks. Collagen levels did not significantly (P>O. 1) affect cooking losses and physical measurements except the width (WI) at he narrow end. Effects of storage were not different for all cooking losses except evaporation losses nor for physical measurements except WI and the longest axis (Ll). Cooking treatments affected all cooking losses and physical measurements except the midpoint thickness of the steak. Random fiber steaks tended to need less time to reach each end-point temperature than aligned steaks. Orientation of fibers had no effect (P>O.l) on cooking losses and physical measurements except Ll and the straight region (L2) on the perimeter of the steak. Broiling yielded higher evaporation and total cooking losses than roasting. Drip losses were not different between heating methods. For both collagen levels and fiber alignments, site 1 (apex of the dome) had higher residual moisture and fat contents than site 3 (no visible change occurred). The possible mechanism for dome formation considers that: 1) complete layers of parallel muscle fibers form heavy barriers; 2) sufficient binding exists between meat pieces to form a dome; 3) excessive protein films (coat) cover meat particles; 4)a dense protein matrix traps moisture and fat components; 5)additional denatured collagen provides strength to support the dome; and 6) "microvoids" exist within the dome with larger voids in the vicinity of the dome. A possible mechanism for channel development is based upon the following observations: 1) sufficient layers of parallel muscle fibers are lacking; 2) insufficient binding exists between meat pieces; 3) insufficient protein films (coat) cover this area; 4) poor protein matrix allows more moisture and fat components to escape into the atmosphere and meat drippings; 5)prominent channels are located between muscle strands connecting the interior and exterior portions of the steak; and 6)voids are located on the steak surface among parallel muscle fibers.
- Masters Theses