The effects of storage temperature and time on the survival and
fermentation activity of L. casei and oxidative stability of omega-3
rich oil when they were microencapsulated together in whey
protein isolate (WPI)–gum Arabic (GA) complex coacervate solid
co-microcapsules (WPI-P-O-GA) were determined, and compared
with results from microencapsulation of omega-3 rich oil
and the probiotic alone. Synergistically enhanced oxidative stability
of omega-3 rich tuna oil and viability and vitality of L. casei
was observed in these co-microcapsules during storage in those
produced through spray drying. Thus, the co-encapsulation of
omega-3 oil and L. casei in WPI–GA complex coacervate followed
by spray drying produces co-microcapsules with higher
fermentability of bacteria and higher oxidative stability of
omega-3 oil.The mechanism for improved stability of the oil in
co-microcapsules is unclear, but may involve shielding of oil by
the probiotic rich WPI–GA complexed shell matrix and resultant
denser packing providing an improved oxygen barrier.
Further work is required to determine the mechanisms involved.
Whatever the mechanism, it appears that a synergetic
interaction occurs between omega-3 oil and probiotic bacteria
in co-microcapsules that enhances the stability of the omega-3
oil and the viability and vitality of the probiotic bacteria.