| Popis: |
Fresh hamburger was packaged under vacuum or in air in films having different oxygen permeability and stored in a display case at 5 C for 30 days. Bacon was packaged with a laminated material, under vacuum, in air or carbon dioxide, and similarly stored. Aerobic and anaerobic bacterial counts were made at various intervals. In addition, bacon was examined for Clostridium perfringens and lactobacilli. Color changes also were evaluated. Bacterial numbers increased on hamburger with either packaging method. However, growth of aerobes on vacuum-packaged meat was slower than growth on meat packaged in air. Anaerobes increased in numbers in hamburgers in evacuated packages after 3 days in storage and after 6 days in meat in unevacuated packages. Packaging bacon in carbon dioxide resulted in reduction of total numbers of aerobes and lactobacilli. Few C. perfringens were recovered. Color retention was improved for as long as 30 days with either vacuum or CO2 packaging, as compared with air controls. In general, growth of anaerobes occurred earlier on fresh meat packaged under vacuum than in air; the converse was true for aerobic bacteria. Carbon dioxide inhibited bacterial growth on packaged bacon and provided good color retention during storage. |
