Lydia O'Sullivan

Mrs. Lydia O'Sullivan


Research Focus & Metrics

Academic Career Length

3Years (2024-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2024 in Meat and Muscle Biology
Verified
Journal Article
Open access
CNClay J. Newton
Clay J. Newton
LOLydia O'Sullivan
Lydia O'Sullivan
KUKeith R. Underwood
Keith R. Underwood
JGJudson Grubbs
Judson Grubbs
CBChristina Bakker
Christina Bakker
ABAmanda Blair
Amanda Blair
The objective of this study was to determine the influence of grain- and grass-finishing systems on carcass characteristics of bison bulls and proximate and fatty acid compositions of bison steaks. Bison bulls grazed native pasture until approximately 25 mo of age, then were randomly assigned to grain-finishing (n=98) or grass-finishing (n=98) treatments. Bulls were slaughtered at approximately 30 mo of age. Hot carcass weight (HCW), ribeye area, backfat thickness, kidney fat percentage, marbling score, and instrumental color (L*,a*, and b*) of the ribeye and subcutaneous fat were recorded. Skeletal maturity, lean maturity, and fat color were subjectively scored. Strip loins were collected from a sub-sample of carcasses, fabricated into 2.5-cm steaks, and designated for proximate, cholesterol, or fatty acid analyses. Grain-finished bulls had greater (P<0.0001) HCW, dressing percentage, ribeye area, backfat thickness, kidney fat percentage,and marbling score. The a* and b* values of the ribeye and a* value of subcutaneous fat were greater (P<0.0001), but the L* and b* values of subcutaneous fat were less (P<0.0001) for grain-finished bulls. A greater proportion (P<0.001) of grain-finished carcasses had moderately bright red lean color, whereas a greater proportion (P<0.0001) of grass-finished carcasses had moderately yellow fat color. Steaks from grain-finished bulls had an increased percentage of crude protein (P<0.0001), fat (P<0.0001), and ash (P=0.0006) content but less moisture (P<0.0001). Steaks from grain-finished bulls had more (P<0.001) cholesterol and palmitic, stearic, oleic, linoleic, and arachidonic acids in addition to more total fatty acids (mg/g of wet tissue). However, for total fatty acids, grass-finished steaks had a greater (P<0.0001) percentage of polyunsaturated fatty acids. These data indicate that the finishing system influences the composition of bison bull carcasses as well as the nutrient profile of bison meat.

21 March 2024 in Foods
Verified
Journal Article
Open access
PDF file
CBChristina Bakker
Christina Bakker
SESamantha R. Egolf
Samantha R. Egolf
LOLydia O'Sullivan
Lydia O'Sullivan
RCRyan B. Cox
Ryan B. Cox
HRHeather R. Rode-Atkins
Heather R. Rode-Atkins
JGJudson Grubbs
Judson Grubbs
The objective of this research was to investigate the influence of beef hot carcass weight (HCW) on consumer sensory attributes. Beef carcasses (n = 116) were selected based on the USDA quality grade and HCW. Lightweight (LW; 296–341 kg), middleweight (MW; 386–432 kg), or heavyweight (HW; 466–524 kg) carcasses with USDA Choice (LC) or USDA Select (SEL) quality grades were used in this study. Carcasses were tracked through fabrication and the semitendinosus, chuck roll, and strip loin were collected and fabricated into eye of round, Denver cut, and strip loin steaks, respectively, for consumer sensory evaluation. USDA Select MW Denver cut steaks had increased overall liking and texture liking scores and were more tender and juicier than the SEL LW steaks (p ≤ 0.02). USDA Select MW strip loin steaks had increased overall and flavor liking scores and were more tender than the SEL LW steaks (p ≤ 0.02). USDA Choice MW eye of round steaks had increased overall, flavor, and texture liking scores and were juicier than the LW eye of round steaks (p ≤ 0.04). The steaks evaluated in this study were differentially impacted by HCW and little to no clear pattern of effects could be determined across cut or quality grade. Additional research is needed to determine the most acceptable HCW from a consumer perspective.