Taking color-score readings, in this case, using a Minolta colorimeter, is one step in measuring pork quality.

Pale, soft and exudative pork is harder to find in U.S. pork today.

The PSE incidence is now at 3.34 percent, according to a nationwide pork packing industry survey conducted in 2005. That’s down from 15.4 percent in 2002. The National Pork Board and the University of Missouri conducted the study.

Researchers conducted this survey as a follow-up to the 2002 study because it became apparent in that study that PSE cases may have been unusually high. Some participants rejected the product if it showed one or two of the PSE quality characteristics— pale, soft or exudative. More typically, a cut is identified as PSE if it reflects all three characteristics.

In the 2005 survey, University of Missouri researchers sent surveys to nine of the top 15 packing companies, which include 11 plants that slaughter 82 percent of all U.S. hogs marketed. The goal was to measure classic PSE, meaning each loin would have to exhibit all three PSE characteristics.

Researchers asked questions relative to pork’s subjective color, objective color, pH level, moisture loss, marbling, blood splash and lean firmness.

Here’s a rundown of the survey results from the 11 plants:

  • Nine plants evaluated subjective color. Overall, one of every 50 loins was deemed unacceptable (using NPB’s color standards key) for subjective color.
  • All 11 plants measured objective color with the Minolta colorimeter. The average L*-value was 45.61.

NPB lean color standards run from pale, pinkish/gray to white, with an L*-value of 61 to dark purplish/red, with an L*-value of 31. Ideal color is dark reddish/pink pork with an L*-value of 43.

  • All plants measured loin pH. The average ultimate pH was 5.76, with an acceptable pH range of greater than 5.55 to greater than 5.7.

On average, one in 24 loins had an unacceptable pH level.

  • Eight plants measured exudate (moisture loss). One in 20 loins, on average, was unacceptable based on water loss.
  • Seven plants evaluated loins for quality (marbling), with nine of them using NPB standards for loin quality, which includes color, pH and marbling.

The average marbling level was 1.5 percent to 2 percent. Packers generally viewed levels of 1 percent to 5 percent as acceptable, with 1.5 percent for domestic markets and 2.5 percent for export markets.

  • Six plants evaluated all loins for blood splash. An average of one in 87 loins was unacceptable for blood splash.
  • Six plants regularly evaluate loins for firmness. Those results showed that an average score for loins was “moderately firm.”

Overall, the 2005 survey showed that 3.34 percent of pork loins had all three PSE characteristics. Considering market hog slaughter in 2005, that would have exceeded 3 million loins.

What do these results mean to you as a producer?

All surveyed plants were trying to measure pork quality in some way. The declining PSE incidence shows that various production factors such as genetics, management, animal handling and transport, as well as slaughter, processing and chilling techniques are making positive changes to improve pork quality.

According to Eric Berg, University of Missouri meat scientist, the survey also shows that packers are doing a better job of segmenting and sorting products for various markets. For instance, U.S. consumers generally don’t want to see much marbling in pork, but restaurant chefs prefer high-marbled pork, which adds taste to their creations.

A 3.34 percent PSE incidence is excellent but with record production it still adds up to a lot of hogs, which means there’s still room to improve.