The objective was to determine the effect of "quality grade" (combination of visual color and marbling) or ultimate pH on consumer eating experience of pork chops cooked to different final internal temperatures. The hypothesis was that consumers would rate a greater percentage of pork chops as acceptable when graded "choice," had a greater ultimate pH, or when cooked to 63 °C compared with chops graded "standard," had a lesser ultimate pH, or when cooked to 71 or 82 °C. Consumers (264 total) were served chops in 1 of 2 experiments. Chops in Exp. 1 were classified as "choice" when NPPC visual color score ≥3 and visual marbling score was ≥2 or "standard" when NPPC scores did not meet the qualifications for "choice" and were cooked to either 63 or 71 °C. Chops in Exp. 2 were categorized as high pH (5.88 to 6.23) or low pH (5.36 to 5.56) and cooked to 63, 71, or 82 °C. Chops were cooked with a sous-vide device (ANOVA Precision Cooker, Anova Applied Electronics, San Francisco, CA) in a water bath. Consumers used a 9-point Likert-type score system where scores 1 through 3 were considered not tender, not juicy, not flavorful, or unacceptable. Scores 4 through 6 were consider neutral for tenderness, juiciness, flavor, and overall acceptability. Scores 7 through 9 were considered tender, juicy, flavorful, and acceptable. Data were organized as a percentage of responses and analyzed using the GLIMMIX procedure of SAS for both experiments with models including treatment (quality grade, ultimate pH, and final internal temperature) and all interactions. Quality grade did not affect (P ≥ 0.30) consumer ratings for any sensory trait. More (P < 0.01) consumers rated chops with a high pH (36.07%) as juicy compared with chops with a low pH (24.29%), but pH category did not alter (P ≥ 0.13) perceptions for tenderness, flavor, or overall acceptability. In both studies, a greater (P < 0.001) percentage of consumers rated chops cooked to 63 °C as acceptable compared with chops cooked to 71 °C. Therefore, internal cooking temperature has a greater impact on consumer eating experience than "quality grade" or ultimate pH.

Today, the United States exports 2.2 million tons of pork and pork products annually, representing just over 26% of U.S. pork production. In order to meet specific demands of a growing export market, pork quality and carcass characteristics are now integrated into breeding objectives. Color and marbling are 2 loin quality traits that influence consumer acceptability of pork and while correlations between early and aged ventral quality have been established, it is unclear if those correlations differ between production objectives (meat quality vs. lean growth). Therefore, the objective of this experiment was to compare correlations among early postmortem ventral loin quality characteristics and aged ventral loin and chop quality characteristics between pigs sired by either Pietrain (lean growth) or Duroc (meat quality) boars. Early postmortem (~1 d) quality traits included: instrumental and visual color, marbling and firmness, and loin pH on the ventral surface of the loin. Loins were aged until 14 d postmortem in vacuum packages. Aged quality traits included traits evaluated early as well as Warner-Bratzler shear force (WBSF) and cook loss. Correlations were compared between Pietrain and Duroc-sired pigs using a Fisher's z-test. Early instrumental lightness (L*) was moderately correlated with aged ventral L* (Pietrain r = 0.47; Duroc r = 0.65) and aged ventral visual color (Pietrain r = 0.42; Duroc r = 0.58). Early ventral visual color was moderately correlated with aged chop L* (Pietrain r = 0.46; Duroc r = 0.60) and aged chop visual color (Pietrain r = 0.45; Duroc r = 0.57). Early visual marbling was strongly correlated (Pietrain r = 0.68; Duroc r = 0.84) with aged chop visual marbling. Within the Duroc-sired pigs, early L* was moderately correlated with aged chop L* (r = 0.64) but only weakly correlated (r = 0.35) within the Pietrain-sired pigs and those correlations differed at P ≤0.02. Within the Duroc-sired pigs, early ventral visual color was moderately correlated with aged pH (r = 0.44) and aged ventral L* (r = 0.57) but only weakly correlated (r ≤ 0.29) within the Pietrain-sired pigs and those correlations differed at P ≤0.03. No early postmortem quality traits were correlated (|r| ≤ 0.34) with WBSF or cook loss for either sire line. In summary, correlations between early and aged postmortem quality traits rarely differed between Duroc- and Pietrain-sired pigs. It is not necessary to account for sire line when relating early and aged quality characteristics.

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The objective was to determine the change in extractable lipid concentration during cooking of boneless pork chops to different endpoint temperatures. Pork loins (152 total) were used and three consecutive chops were cut from each loin. Chop 1 was evaluated raw (not cooked) for intramuscular fat (IMF) percentage. Raw IMF percentages were used to categorize the remaining 2 chops, from each loin, into low, average, and high marbling bins. The low bin included ≤ 3% IMF, the average bin included 3 to 4% IMF, and the high bin included ≥ 4% IMF. Chop 2 was cooked to 63°C and chop 3 was cooked to 71°C to evaluate cook loss, Warner-Bratzler shear force (WBSF), and IMF percentage. When cooked to either 63°C or 71°C, high IMF chops maintained greater (P &lt; 0.001) IMF percentage than average and low IMF chops. Additionally, average IMF chops maintained greater (P &lt; 0.001) IMF percentage than low chops, regardless of endpoint cooking temperature. The three marbling categories did not differ in cook loss (P = 0.28) or WBSF (P = 0.23) when chops were cooked to either 63°C or 71°C. However, both WBSF (2.76 kg) and cook loss (18.72%) were decreased (P &lt; 0.001) in chops cooked to 63°C compared with chops cooked to 71°C (3.08 kg, 23.45%). Overall, differences in IMF percentages persisted even after cooking. Furthermore, IMF percentage of pork chops did not affect tenderness.

The objective was to determine the effect of ultimate pH or “quality grade” (combination of color and marbling) on consumer eating experience of pork chops cooked to different final internal temperatures. The hypothesis was that consumers would rate a greater percentage of pork chops as acceptable with a greater pH, when graded “choice”, or when cooked to 63°C compared with 71°C or 82°C. Consumers (264 total) were served chops in 1 of 2 experiments. Experiment 1 assessed chops as high pH (6.23–5.88) or low pH (5.36–5.56) and cooked to 63°C, 71°C or 82°C. Experiment 2 classified chops as “choice” when NPPC color score ≥ 3 and marbling score was ≥ 2 or “standard” when NPPC scores were below “choice” and cooked to 63°C or 71°C. Chops were cooked with an immersion heater (ANOVA Precision Cooker, Anova Applied Electronics, San Francisco, CA) in a water bath. Consumers used a 9-point Likert-type score system where 1 was extremely tough, dry, bland, or unacceptable and 9 was extremely tender, juicy, flavorful, or acceptable. Data were organized as a percentage of responses and analyzed using the GLIMMIX procedure of SAS for both experiments with models including treatment (pH or quality grade category, temperature and all interactions). More (P < 0.01) consumers scored chops at 7, 8, or 9 for juiciness with a high pH (36.07%) compared with chops with a low pH (24.29%), but pH category did not alter other traits (P ≥ 0.13). Quality grade did not affect (P ≥ 0.30) consumer ratings of any sensory trait. In both studies, a greater (P < 0.001) percentage of consumers rated chops cooked to 63°C as acceptable compared with chops cooked to 71°C. Therefore, internal cooking temperature has a greater impact on consumer eating experience than ultimate pH or “quality grade.”