مطالعه زنده‌ مانی گونه‌های مختلف باکتریایی و خواص حسی دو نوع ماست پروبیوتیک در طی تولید و نگهداری

Introduction: Because of many health benefits, production and cosumption of probiotic products was incresead worldwide. Viability of probiotic bacteria and sensory propperties are important factors in quality of probiotic yoghurt. Many factor can affect the sensory property and survival of probiotic bacteric in yoghurt. Thus, the aim of this study was to assess the the viability of probiotic bacteria and sensory properties of two kind  probiotic yoghurt. Methods: Two kind of probiotic yoghurt  named  as MY 1821 and ABY3 were made using commercial starter culures according to manufacturer instruction. Viability of  probiotic bacteria (lactobacillus acidophilus, bifidibacteria and lactobacillis casei)   and sensory properties (flavour,  mouthfeel, appearance and texture) of yoghut were assessed during 21-days at 7 days interval. statistical analysis was carreid out using T-test and ANOVA (repeated measure) in SPSS software. P value less than 0.05 was considered as significant. Results: At the end of experiments the number of  lactobacillus acidophilus and bifidobacteria were 7.42± 0.04  and  6.90 ± 0.06 log cfu/gr  in MY1821 and 6.45 ± 0.11 and 6.16  in ABY3 and the number of lactobacillis casei was 7.55± 0.04 log cfu/gr  in MY 1821. population  of lactobacillus acidophilus and bifidobacteria  decreased by 1.1 and 0.48 log cfu/gr in MY 1821 And 0.89 and 1.38 cfu/gr in ABY3 yoghurts.viability of  L. casei   also reduced  and by 0.55  Log cfu/gr in MY 1821 yoghurt. At the end of experiments the mean score for flavour,  mouthfeel, appearance and texture were 21.2± 3.09 , 12.36 ± 1.80, 7.2± 1.1.01, 3.86± 0.35 in MY 1821 yoghurt and 17.6±4.22, 10.73±2.46, 6.66± 0.97 and 3.33± 0.49 in ABY3  yoghurt respectively. Conclusion: The number of probiotic bacteria at the end of storage were above the criteria determined by Iran national standard. The result of sensory evaluation showed that the prepared yoghurt had good to excellent acceptance. Thus using these starter cultures by diary industry is recommended. Because of helth benefits of probiotics, consomption of these products for their high population of probiotic bacteria can improve the public health.