Comparison of Sterile and Inoculated Beef Tissue

SUMMARY— A surgical isolator technique was developed for obtaining sterile muscle tissue from a beef carcass. This tissue was compared during refrigerated storage with a general inoculum tissue sample, a low level general inoculum sample, a sample inoculated with Pseudomonas and an Achromobacter sample. Protein fractionation revealed a decrease in sarcoplasmic protein for all treatments during storage. An initial rise, followed by a relatively constant value in the myofibrillar fraction, was also observed for all treatments. The stroma fraction, the nonprotein nitrogen fraction, percent free water, pH and emulsifying capacity of the aseptic and low level inoculated samples remained fairly constant throughout storage. The higher level inoculated samples decreased slightly in stroma protein during storage and increased in nonprotein nitrogen late in the storage period, These same treatments increased in pH, decreased in percent free water and increased in emulsifying capacity (late in storage).