By: Brian D. Paxton, M.S.
The Ohio State University, 1999
Professor C. Lynn Knipe, Adviser

Improving pork quality is an important economic concern to pork processors today. The processing quality of pork from pigs with the Napole gene was evaluated in order to improve functionality. Paired hams from 33 hogs were obtained and glycolytic potential (GP) was determined. One ham of each pair was stored frozen and the other non-frozen. Two processing methods were also applied to each pair of hams. One method involved using a conventional curing solution, while the other method was a curing solution with the addition of 0.125% sodium hydroxide (NaOH). The frozen hams had a confounding effect of nitrite, while no nitrite was added to the unfrozen hams. Samples from the 66 frozen hams were served in a taste panel for evaluation of sensory qualities. Phase 2 processing methods were the same as phase 1, but ham treatments were applied at the same time, under the same conditions, and all contained nitrite.

Hams from high GP animals were found to have decreased pH, cooking yield, Minolta L* (lightness), and increased Minolta b* (yellowness) and tenderness. No differences in cured product package purge were found between GP groups. Both the freezing treatment and NaOH treatment were found to significantly (P<.0001) increase the pH, cooking yield, and decrease Minolta L* and b* of cooked hams. This increase in cooking yield from both treatments was found to be greater in hams from RN- animals. Frozen hams were found to possess significantly (P<.05) less package purge after raw and cured product storage.

No significant (P>.05) differences were observed between low and high GP groups for any of the four sensory characteristics. Sensory results of NaOH-treated hams found significantly (P<.05) more tenderness and juiciness than controls. For those hams processed with the conventional solution, a significant (P<.05) increase in tenderness was observed for hams from RN- animals. However, when NaOH was added, an increased and more consistent tenderness was observed across GP. No significant (P>.05) difference was found between chemical treatments for ham-flavor intensity and off-flavor intensity, indicating panelists were unable to detect off-flavor or loss of ham-flavor that may accompany the addition of NaOH.

The addition to hams of frozen storage and treatment with 0.125% NaOH would be very beneficial to pork processors. Not only do these treatments help to decrease the difference in the quality of meat between RN- and rn+ pigs, they also slightly improve the quality of meat from rn+ pigs.