inoculated with 50 mg of lyophilized Bifidobacterlum bifidum, and in- cubated at 37 C in anaerobic jars for 18 h. The supplemented MRS broth containing B. bifidum was diluted to 1x 10 ° cells / ml, 0.1 mL of which was inoculated into 9.9 ml supple-mented MRS containing 3% (w / v) of BRF and incubated at 37 "C in anaerobic jars. for 24 h. A negative control (without B. bifidum) was used to eliminate sample influence of turbidity After incubation, the tubes were centrifuged (3000 xg) for 10 min and the supernatant was dis carded Then, 15 mL of PBS (0.1M phosphate buffer pH 7.4, 0.9% saline) was added and the tubes were mixed. Dilution was made by adding 2.1 ml of this mixture to 4.9 ml of PBS in spectrophotometer tubes. Turbidity was measured at 600 nm using a spectrophotometer UV / Vis DU70 ( Beckman Instruments, Inc., Fullerton, USA). All mea surements were performed in quadruplicate and repeated twice. Bacterial growth was calculated as. Turbidity of the sample containing B. bifidum - negative control.