Harvest practices cause aberrations in pork quality

Consumers are often confused and reluctant to purchase products from fresh retail meat counters that exhibit significant color variations. This hesitation to purchase results in annual profit loss to the pork industry. Processes to minimize color variation remain a major focus of the industry and many meat science programs across the globe. Previously, we found inherent muscle characteristics contribute to variations in pork quality but these characteristics fail to explain the high frequency of two-toning and other pork quality defects routinely occurring in many hog processing facilities. Therefore, we hypothesized harvesting practices, such as scald alter color across muscles of the ham. Scald time was initially investigated using 32 carcasses subjected to either a 4 (n=16) or 8 (n=16) min scald time. Samples were collected before or after scalding and at 24 hrs. A 50% reduction in scald time resulted in (p < 0.0001) lighter muscle color (L*) early postmortem, although the 8 min scald treatment was lighter (p < 0.005) at 24 hrs. Although differences in pH (p < 0.0001) and color were noted, ultimate carcass temperature was not affected. To that end, we moved to validate our hypothesis in an industrial plant setting. Carcasses (n=200) were assigned treatments of 6.5 or 7.5 min scald times, and SM muscle samples were collected at 24 hrs. Surprisingly, the shorter scald time resulted in (p < 0.05) a lighter color, contradicting our first study. To explore this color issue further, we uncoupled scald from the dehairing process. To achieve this goal, carcasses (n=24) were assigned to either an 8 or 16 min time to dehair, with or without scalding. Protracted time to dehair resulted in higher ultimate pH (p < 0.005) and less color variation across the muscle (p < 0.05). Though a color gradient remained, the variation across the muscle was reduced by increasing time to dehair. These data show time to dehair affects pork quality development and suggest that delaying time to physical manipulation of the carcass may improve pork color, thus increasing consumer acceptance.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Animal and Poultry Sciences

Department dc:contributor.department

Animal and Poultry Sciences

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2019

Author dc:creator

• Daniels, Rachel Page

Chair dc:contributor.committeechair

• Gerrard, David E.

Committee members dc:contributor.committeemember

• Sutton, Douglas Scott
• El-Kadi, Samer Wassim
• Shi, Hao

• pork
• ham
• harvesting
• muscle metabolism
• two-toning
• scald
• dehair

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

vt_gsexam:21679

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/93175