2.2. Sample collection and preparation
Pigs were harvested at a USDA inspected facility. Loins (Longissimus thoracis et lumborum) from the left side of the pig were collected 1 day postmortem, placed in bags along with their respective identification tag, and transported with ice packs to the Iowa State University Department of Food Science and Human Nutrition Sensory Evaluation Unit (Ames, IA).
After aging for 10 days at 4 °C, loins were cut. The loin was cut 15.24 cm from the sirloin end to make a roast. The roast was then vacuum packaged and frozen. Next, two 2.54 cm chops were cut, vacuum packaged, and frozen. The chop cut closest to the roast was used for pork quality measurements and the next following chop was used for sensory analysis. These samples were frozen at − 20 °C for a minimum of 14 days to a maximum of 30 days before analysis. The second half of the loin, starting with the side opposite of the blade end, was cut into two 2.54 cm chops followed by a 15.24 cm roast. These samples were weighed and used for fresh analysis. The first chop was used for sensory analysis and the second chop, located closest to the roast, was used for pork quality measurements. Every sample was trimmed to approximately 6 mm of subcutaneous fat. After cooking, each roast was faced and cut into four 2.54 cm slices. Slices closest to the sirloin end and blade end of the loin were used for pork quality measurements. The remaining 2 slices were used for the sensory analysis.