The tolerance of L. paracasei LBC 81 at different acidic solutions
with pepsin was determined by solutions with pH 1.5; 2.5 and 3.5
during the storage time. The solutions were prepared by diluting
3 g of pepsin (fromporcine stomach mucosa Pepsin, SigmaeAldrich
CO. St. Louis, MO) in 1L of sodium chloride solution (2.0 g/L). Subsequently,
the solutions pH was adjusted with HCl and NaOH 1N.
The solutions at different pHs were transferred (9 mL) into tubes
containing probiotic or symbiotic creamy milk desserts (1 g). Then
underwent agitation of 150 rpm at 37 C in shaker (Fermentation
Design inc MOD G25). After 1 and 2 h an aliquot (1 mL) of each
solution was taken and subjected to serial dilutions. To determine
the count of viable cells, 1 mL of the dilution was inoculated
through deep seeding in acidified MRS agar and incubated anaerobically
at 37 C for 72 h