Abstract:
Probiotics are the cultures of live microorganisms
which, when administered in adequate amounts confer a
health benefit on the host. Fermented dairy products are
considered as a suitable vehicle to carry probiotics where
yogurt is the most common vehicle for incorporating
probiotics. However the survival of probiotics can be
affected by the food processing conditions as well as
the low acidic environment of the gut. Encapsulation of
probiotic bacteria can be considered as a suitable method to
preserve the probiotics until they reach their site of action.
The study was conducted in order to evaluate the effect
of encapsulation on the survival of probiotic bacteria in
acidic condition. Bifidobacterium animalis sub sp lactis
(BB12) was encapsulated with sodium alginate and resistant
starch and their survival was determined in yogurt as
well as in simulated gastric condition. BB12 was mixed
with 10 ml of 18g/L sodium alginate and 10 ml of 20g/L
resistant starch and dropped in to sunflower oil in order
to make encapsulated beads. Calcium chloride solution
was used to harden the beads. pH change and titratable
acidity of the yogurt added with encapsulated beads were
measured. The number of encapsulated BB12 in yogurt
declined by about 1 log10 CFU/ ml over the twelve days
of storage, while the non-encapsulated bacterial viability
declined by about 2 log10 CFU/ ml. The encapsulation of
BB12 showed 1 log10 CFU/ ml decline over three hours
of exposure to simulated gastric condition (pH 2.0, 3.0
and 4.0) where the non-encapsulated bacteria showed
2 log10 CFU/ ml decline for pH 3.0 or 4.0 at the same
time 3 log10 CFU/ ml was observed for pH 2 treatment.
A successful encapsulation was made using alginate and
starch, but in overall the survival rate of encapsulated
and free bacteria did not show any statistical difference
