Researching Pork Quality

Today's consumer is looking for a meat product with great color, consistent quality and exceptional taste. The key to meeting the demands of the entire pork chain is on-going research. Babcock has focused on several pork quality traits in our research projects - traits we feel are important to our customers to guarantee their competitive edge in the market place. In order to better understand pork quality research, we thought it would be helpful to review pork quality measurements and tests.

Pork quality measurements begin with live weight and carcass weight. Dressing percent or yield is calculated from the ratio of these two weights. Backfat and loin depth are measured on the hot carcass and used to estimate percent lean of the animal. Most premiums paid today are based on a measure of percent lean. Hams and loins are separated from the carcasses and weighed, providing us with ham and loin percentage. There has been some indication that packers may be interested in paying for the weight of the primal cuts rather than simply percent lean.

More often these carcass measurements are relatively standard, and are not a part of pork quality discussion. More typical pork quality measurements include loin pH, color, marbling, firmness, and drip loss.

Loin pH has little economic importance, but is often used as a predictor of other measures of pork quality including color, moisture and firmness. It is used to predict whether carcasses will be PSE (pale, soft and exudative), DFD (dark, firm and dry), RSE (red, soft and exudative) or RFN (red, firm and normal). Packers are especially interested in using pH to decide which carcasses should be exported.

Color is measured using the Minolta Chromameter. Consumers tend to favor a reddish-pink color in the meat case with a minimal amount of marbling showing.

Marbling is measured chemically based on total lipid (fat) content of raw, trimmed loin muscle. Too much marbling becomes a problem in the meat case, as consumers will shy away from it. Too little marbling is believed to negatively affect the taste and moisture content of cooked pork.

Tenderness of the meat is measured using the Warner-Bratzler shear test. This test is used to predict the chewiness of meat.

Color, marbling and firmness of the loin is also measured subjectively, using the 1-5 NPPC scales.

Drip Loss is measured by removing small samples of meat from the carcass over an extended period of time. Drip loss has the greatest economic loss to the packer. The loss begins with the hanging carcass. It gets worse when the carcass is cut into primals and is probably most noticeable when moisture lies in the bottom of a package at the meat counter.

Measuring cooked loin measurements are also planned. Cooked loin tenderness is measured either by a trained sensory panel or by the Universal Testing Machine using the star probe. Loin cooking loss will be measured as the difference in weight between a piece of loin before cooking and after cooking.

All of the above pork quality measurements are used on loin samples, and many are also used on ham samples when research is being conducted.