evaluation of survival of encapsulated probiotic bacteria in synbiotic yog-ice cream

in this study, frozen yoghurt was produced as a synbiotic product. a food product containing both probiotics and prebiotics is named as synbiotic or functional food. lactobacillus acidophilus (la-5) as a probiotic bacteria was added to frozen yoghurt in two types; free and encapsulated, and its survivability was evaluated during 60 days storage at -18 °c . also fructo-oligosaccharide as a prebiotic compound was used for producing frozen yoghurt in different levels (0%, 0.4% and 0.8% (w/w)). the viable cell number in free state in samples with (0%, 0.4% and 0.8% (w/w)) fructo-oligosaccharide was 3.8×109 cfu/ml, 3.5×109 cfu/ml and 3.8×109 cfu/ml and after 60 days of storage these numbers were decrease to 2×107 cfu/ml, 2.2×107 cfu/ml and 2.2×107 cfu/ml respectively. whereas in encapsulated state, the viable cells in samples with (0%, 0.4% and 0.8% (w/w)) fructo-oligosaccharide these numbers was 7.5×109 cfu/ml, 8.9×109 cfu/ml and 9.8×109 cfu/ml and after 60 days, these numbers were decreased to 2.13×109 cfu/ml, 2.5×109 cfu/ml and 2.9×109 cfu/ml.the results indicated that encapsulation of l. acidophilus could significantly (p<0.05) improve its survivability in a higher level than the investigated levels by the international dairy federation (107cfu/ml).