TBA values, sensory characteristics, and volatiles in ground pork during long-term frozen storage: effects of packaging

Ground pork (30% fat) was packaged in vacuum bags (V), polyvinyl chloride film (P), Saran Wrap(S), aluminum foil (A), or Saran-aluminum foil combination (SA) and frozen at -17 degrees C for 13, 26, and 39 wk. Samples were analyzed for TBA value and pH. Volatiles were steam distilled, volatilized at 60 degrees C, and 1 mL samples of headspace gas was analyzed using gas chromatography and mass spectrometry. Spectra for individual peaks on the total ion chromatograms were identified with spectra from known standards. Ground pork (cooked to 75 degrees C) was evaluated by a trained sensory panel for flavor and texture. Rancid and acid odor and flavor scores and TBA values increased over time regardless of packaging treatment; however, V-packaged pork had lower scores and P-packaged had higher scores at all time periods than did that in other materials. Eighteen volatiles were identified and quantified using GC/MS; 3-hydroxy-2-butanone had the highest correlation coefficients with TBA value, odor, and flavor scores