Effects of sodium chloride and lactates on chemical and microbiological changes in refrigerated and frozen fresh ground pork

Changes in fat oxidation and color of freshly ground pork, 14% fat, during storage at 2 degreesC for 15 days and at -20 degreesC for up to 70 days were determined. The fresh meat was further treated with NaCl (1 and 2%, by weight), sodium or potassium lactate (2%), and combinations of NaCl and lactates. The microbial stability of the refrigerated meat was enhanced by the lactates, and their combinations with NaCl were more effective than lactates alone in delaying the onset of spoilage. Changes in TBARS were seen in the untreated meat only after it was judged spoiled when stored at 2 degreesC (day 7), and after 69 days at -20 degreesC. Among treatments, fat stability was highest in lactate-treated meat, and TBARS values were generally similar to those in untreated meat. NaCl enhanced fat oxidation, and the effects of 2% salt were significantly higher than those of 1% (P<0.05). Combinations with lactates reduced the prooxident effects of NaCl at both storage temperatures, and the effects were more pronounced in meat with 2% NaCl stored at -20 degreesC. The red color (a* value) was enhanced by NaCl and lactates immediately after their addition to the meat. However, values for all treatments, including the untreated meat, declined rapidly after 4 days at 2 degreesC, and were 50-70% lower than the initial values after 8 days. Color stability in the frozen meat was highest in control and lactate-treated samples throughout the storage period. It was lowest in samples with 2% NaCl, whether alone or in combination with lactates. Sodium or potassium lactate (2%) enhanced the microbial stability of refrigerated pork without deleterious effects on its color or fat stability. Combinations of lactates with NaCl improved the fat stability, particularly during storage at -20 degreesC, by reducing the prooxidant activity of NaCl. (C) 2002 Elsevier Science Ltd. All rights, reserved.