Intramuscular fat content has little influence on the eating quality of fresh pork loin chops

¹ Department of Animal Science, University of Illinois, Urbana 61801
² Department of Food Science and Human Nutrition, University of Illinois, Urbana 61801

^* To whom correspondence should be addressed. E-mail: mckeith{at}uiuc.edu.

	Abstract

Fresh pork loins (n = 290) were selected from a commercial packing facility based on subjective marbling of the intact loin and 24 hr pH in order to determine the influence of marbling on sensory attributes. The study was designed using pigs from a similar genetic background, raised in similar production facilities, and harvested on a single kill day to minimize the effects of genetics, management, environment, and slaughter day. Loins were vacuum packaged, transported to the University of Illinois Meat Science Laboratory, and aged for 7 d after which a chop was removed from the area of the tenth rib for proximate analysis. Quality measurements including NPPC color, marbling, and firmness, ultimate pH, Minolta L*, a* and b*, and drip loss were determined after aging. Once proximate composition was complete, 150 loins were selected to provide a continuous and uniform distribution of extractable lipid ranging from 1 to 8% and a pH range from 5.5 to 5.8. Trained sensory panel analysis (endpoint cooking temperatures of 62°C, 71°C, and 80°C) as well as Warner-Bratzler shear force (cooked to 71°C) were performed on chops from the 150 loins. Consumer evaluation was also conducted on a subset (n = 40) of these loins that were broken down into five discrete levels of intramuscular lipid with averages of 1.6, 2.5, 3.6, 4.5, and 5.7% extractable lipid. Consumers were also asked to select the chops that they would most prefer from a retail display case based on the amount of marbling present. Results from the consumer portion of the study indicated that intramuscular fat content had limited effects on perceived tenderness, juiciness, pork flavor, and oiliness. Some significant differences (P < 0.05) were detectable, but they were numerically small. Most consumers also selected lean chops from the retail case with almost 50% selecting chops with less than 1.7% extractable lipid. Warner-Bratzler shear force was negatively related (P < 0.0001), to extractable lipid with a R² value of 0.10. Results from the trained panel sensory analysis indicate that percent extractable lipid does not correlate strongly with perceived tenderness, juiciness, or pork flavor for this group of pork loins that was controlled for genetics, pH, management, and day of harvest.

Key Words: consumer, lipid, marbling, pork, quality, sensory