Viability of Lactobacillus gasseri and its cholesterol-binding and antimutagenic activities during subsequent refrigerated storage in nonfermented milk

The effect storage at 4 degrees C on the viability of lactobacillus gasseri and its sodium taurocholate-deconjugating and cholesterol-binding abilitie s as well as desmutagenic activity was investigated. Unfermented milks cont aining L. gasseri strains SBT0274 and SBT0270 at 10(9) cfu/ml were prepared using 10% skim milk. Total and bile-tolerant lactobacilli for strains SBT0 274 and SBT0270 generally decreased after 14 d of storage at 4 degrees C; h owever, viable cells of these strains were still at 10(8) cfu/ml after 28 d of storage. The amounts of cholic acid released and of cholesterol bound b y strains SBT0274 and SBT0270 declined over time, especially at 21 d of sto rage. Antimutagenic activity of unfermented milk made from both strains was attributed to the bacterial cells, and the activity was stable during stor age at 4 degrees C for 28 d.