Color improvement and shelf life extension of fresh red meats packaged with chitosan coated films.

摘要

Fresh, red beef chuck rolls were packaged in chitosan-coated films to investigate the potential for improved red meat color and extended shelf life. Preliminary tests with the Shake Flask and Film Direct Contact Studies showed that chitosan film significantly (P 0.05) reduced Escherichia coli, Weissella viridescens, and mold counts over 96 hours of storage at ambient temperature and at incubation temperatures of 35°C and 21°C. The Zone of Inhibition Test showed that no growth of E. coli, W. viridescens , and mold was observed under the disks of chitosan film in direct contact with agar media.; Sliced chuck rolls in contact with chitosan film packaged in Cryovac ® E301T E-Bags (Oxygen transmission rate: 4000 cc at 73°F, 1 atm., m2, 24 hours) overwrapped in Cryovac B550 Barrier Bags (Oxygen transmission rate: 3–6 cc at 40°F, 1 atm., m2, 24 hours, 0% R.H.) retained the red meat color while still having significantly (P 0.05) lower microbial numbers than samples without chitosan film in the same packaging materials.; Six and nine days post-mortem chuck rolls packaged in chitosan coated Cryovac E-Bags overwrapped in Cryovac Barrier Bags were tested from Day 0 to Day 9+3 (days in dark storage at 32 to 34°C + days in a lighted open display case from 36 to 38°C) and from Day 0 to Day 6+2 (days in dark storage at 32 to 34°C + days in a lighted open display case from 36 to 38°C).; Overall, the vacuum packaging augmented with chitosan coating significantly (P 0.05) improved red meat color retention compared to vacuum packaged samples without chitosan from Day 0 to the final testing day. Also, vacuum packaging with chitosan coating significantly (P 0.05) delayed the growth of E. coli and lactic acid bacteria from Day 0 to the final testing day compared to samples without these combined hurdles.