Effects of dietary magnesium and duration of refrigerated storage on the quality of vacuum-packaged, boneless pork loins

Quality data were initially collected on 78 pork loins from crossbred pigs fed diets containing 0, 1.25 or 2.5% magnesium mica (MM). Loins were then v acuum-packaged, and randomly assigned to either 4 or 8 weeks of storage at 2 degreesC. Dietary MM had no (P > 0.05) effect on moisture loss/retention or subjective and objective color measurements. Purge volume increased (P < 0.05) and drip loss decreased (P < 0.05) as storage time increased. Moreov er, longissimus thoracis et lumborum (LM) chops became lighter (P < 0.05), redder (P < 0.05), and more yellow (P < 0.05) during 8 weeks of storage. Al though TBARS values increased linearly (P < 0.001) during extended storage, LM chops from pigs fed 2.5% MM tended to have lower (P < 0.07) TBARS value s after 4 weeks of storage than chops from pigs fed 0 and 1.25% MM. After 8 weeks of storage, however, there was a tendency for TBARS values of chops from pigs fed 1.25% MM to be lower (P < 0.07) than chops from pigs fed 2.5% MM. Even though feeding swine diets containing MM did not affect color and water-holding capacity of pork loins during storage, the data indicated in clusion of MM in swine diets may retard onset of oxidative rancidity in vac uum-packaged pork loins. (C) 2000 Elsevier Science Ltd. AU rights reserved.