Growth of Salmonella typhimurium and Mesophilic Organisms on Beef Steaks as Influenced by Type of Packaging .

Two trials, each utilizing 72 samples of fresh beef loin steak, were done to determine the effects of various packing systems upon growth of Salmonella typhimurium . Samples were inoculated with 10 cells/cm of the organism and randomly assigned to four packaging treatments: (1) overwrapping in oxygen-permeable film; (2) vacuum packaging; (3) packaging in barrier bags flushed with a 60% CO: 40% O gas atmosphere then evacuated and sealed; and (4) packaging in barrier bags filled with a 60% CO: 40% O gas atmosphere. Twelve steak samples were inoculated with S.

Growth of Staphylococcus aureus on Beef Steaks as Influenced by Type of Packaging .

Beef loin steaks were inoculated with 10 cells of Staphylococcus aureus /cm in two separate trials to determine the effects of different packaging treatments upon the organism's growth. Each trial utilized 72 samples which were randomly assigned to four packaging treatments: (1) over-wrapped in oxygen-permeable film; (2) vacuum packaged; (3) packaged in barrier bags flushed with a 60% CO : 40% O gas atmosphere then evacuated and sealed; and (4) packaged in barrier bags filled with a 60%CO : 40% O gas atmosphere. In each treatment group, 12 samples were inoculated with S.

Quality Changes of Beef Steaks Stored in Controlled Gas Atmospheres Containing High or Low Levels of Oxygen .

Steaks from bovine Longissimus and Semimembranosus muscles were used to determine the influence of gas atmospheres on beef color, microbial growth and shrinkage during 9 days of retail display in two separate experimental trials. Steaks were displayed in one of four gas mixtures and were compared to steaks packaged under conventional vacuum and in a film wrap. Gas mixtures containing O levels of 10% (one-half ambient) did not maintain a bright red color, but those with 40-75% O (more than twice ambient) maintained acceptable color for 9 days of storage.