Inhibition of Spoilage Bacteria by Acidification of Soy Extended Ground Beef

摘要

ABSTRACTBacterial isolates from soy extended ground beef were used to test the effect of pH on their growth in trypticase soy broth (TSB), ground beef, and ground beef + 20 textured soy protein (TSP). Growth was measured in TSB acidified with hydrochloric, citric, lactic, or acetic acids at pH levels from 5.4–6.2. After incubation at 4°C for 7 days, acetic acid was determined to inhibit growth to the greatest extent with no growth at or below pH 5.8. Growth response was studied in meat blends at pH levels of 5.4, 5.7, 6.0, and 6.3. Growth was suppressed in ground beef initially at pH 5.4 and in ground beef + 20 TSP initially at pH 5.4 and 5.7. This resulted in an increased shelf life of 2 days in acidified blen