Producing the inoculum and dairy beverages
The B. lactis inoculum was prepared by adding 1 g of culture to 100 mL of UHT goat milk and statically incubating the mixture at 35 C for 12 h.
The viability of the B. lactis was determined according to the procedure detailed in Section 2.6 over 24 h, at 2 h time intervals.
For this analysis, bacterial suspensions were serially diluted at each time interval in peptone water (105 e109), and the viable cell counts were determined and expressed as the logarithm of colony forming units per mL of product (log CFU mL1) (data not shown).
At 12 h of incubation, the counts were approximately 1011 CFU mL1, and they were stable or decreasing until 24 h.
The production of these dairy beverages consisted of the homogenization and pasteurization (65 C 30 min1) of sucrose
(70 g L1), powdered chocolate (28 g L1), gums (2 g L1) and goat milk.
Pasteurized goat cheese whey and/or prebiotics were added and homogenized according to each formulation (Table 2).
During the last step, 20 mL L1 of the inoculum that was prepared as described above and that contained approximately 1011 CFU mL1 was added to the beverage that was stored in plastic bottles (150 mL) at 5 C ± 2 C for 28 days. The same goat milk and goat cheese whey batches were used.