زنده مانی لاکتوباسیلوس اسیدوفیلوس (Lafti-L10) و بیفیدوباکتریوم لاکتیس (Lafti-B94) و تاثیر آنها بر خواص کیفی و ریزساختاری دوغ

In this study, survival of lactobacillus acidophilus (lafti-l10) and bifidobacterium lactis (lafti-b94) and their effect on chemical, sensory and microstructure properties of iranian doogh were investigated during 60 days at 5±1°c. three treatments including c (control, no probiotic), bl containing bifidobacterium lactis and la containing lactobacillus acidophilus were prepared. the results showed that the number of bifidobacterium lactis and lactobacillus acidophilus were decreased from 8.53 to 8.07 log cfu/g and from 8.4 to 7.45 log cfu/g respectively during storage. the ph of sample containing lactobacillus acidophilus were lower than that in other samples and the acidity was significantly higher than the treatment containing bifidobacterium lactis (p < 0.05). the results of study on microstructure showed that lactobacillus acidophilus caused more regular aggregates in casein micelles than bifidobacterium lactis. according to the sensory evaluation, the treatments containing probiotic obtained highest score for flavor in comparison with control samples (p < 0.05). also the final numbers of probiotic bacteria were more than the recommended minimum number necessary for therapeutic effects on human health (106 - 107 cfu g-1) at the end of 60 days. so probiotics not only did not have adversely effect on physicochemical and sensory properties, but also improves the properties of doogh. therefore doogh can be an effective carrier of probiotic organisms.