The combined effect of films of various gas barrier properties, various gas packaging atmospheres (air, vacuum and gas packaging, oxygen absorbents) and storage temperatures (4 and 12$ sp circ$C) were investigated on the color stability and shelf-life of fresh beef. Meat color was described by reflectance measurements and by reading the color coordinates L* (lightness), a* (redness), b* (yellowness), C* (chroma) and h (hue angle) in the CIE-LAB system. All packaged beef was regarded as unacceptable when reflectance differences values at 630 and 580 nm i.e., due to oxymyoglobin (MbO$ sb2)$ were $ sim$30-35. Based on these standards, aerobic packaging of beef in polyvinylchloride (PVC) film had a shelf-life of $ sim$5 d and 1 d at 4 and 12$ sp circ$C respectively. Beef packaged in both low gas-moisture barrier films resulted in black discoloration after only 2 d at 4$ sp circ$C due to increased moisture loss. Longer extensions in both color and microbial shelf-life of fresh beef were possible by packaging products under modified atmospheres using high gas barrier Cryovac$ sp circler$ bags. Both vacuum packaging (VP) and vacuum skin packaging (VSP) resulted in a shelf-life of $ sim$35 d at 4$ sp circ$C. Gas packaging using high levels of CO$ sb2$ (100%) in conjunction with Ageless-SS$ sp circler$ oxygen absorbent, delayed discoloration for $ sim$42 d at 4$ sp circ$C. (Abstract shortened by UMI.)
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.27510 |
| Date | January 1997 |
| Creators | Choucha, Sam E. |
| Contributors | Smith, J. P. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Food Science and Agricultural Chemistry.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001615052, proquestno: MQ37108, Theses scanned by UMI/ProQuest. |
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