Date of Award
Doctor of Philosophy
This study was concerned with effects of different commercial practices on quality of vacuum packaged pork chops. Variables included type of packaging film (high or low barrier to oxygen), presence or absence of bone in the packaged pork chops, length of loin storage time prior to cutting into chops, method of cutting into chops, and length of storage period of packaged chops prior to retail display. The microflora of the pork chops was characterized with regard to numbers of microorganisms, types present, and changes in numbers and types over time. Vacuum packaged pork chops were also tested with regard to organoleptic quality, drip loss, odor, color, and pH;The presence of bone in the chops had little effect on the microbial population, but did influence sensory qualities, drip loss, and odor;Vacuum packaging the chops tripled the shelf life over conventionally packaged chops to about nine days before spoilage was apparent. Neither microbial growth or sensory qualities were significantly different for high or low barrier films, but drip loss was greater with the low barrier film;Chops cut from loins immediately after slaughter, scored higher for sensory qualities than did chops from stored loins;Loins which were subjected to a freeze tempering process prior to being cut showed faster growth of psychrotrophs and lactobacilli than did the refrigerated loins. Cutting method produced no effect in sensory scores but had a large effect on drip loss;Storage of chops in the dark prior to display under light caused inhibition of microbial growth but had little effect on organoleptic qualities or drip loss. Total Volatiles Relative to Nonane (TVRN) increased upon exposure of chops to light in a display case;The results of this study demonstrate the advantages of vacuum packaging over hand wrapping pork chops, indicate that loins may be held up to seven days prior to cutting without undue loss of quality, that storage of chops in the dark is a feasible holding practice and that a freeze thawing process has less desirable effects on the microbiological quality and drip losses of pork chops compared with refrigerated chops.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
William Joseph Lulves
Lulves, William Joseph, "Quality changes in vacuum packaged fresh pork " (1981). Retrospective Theses and Dissertations. 7445.