INVESTIGATING THE EFFECT OF HYDROCOLLOIDS ON SURVIVAL BIFIDOBACTERIUM BIFIDUM IN YOGURT

Background and Aim:Among the different foods act as a probiotic carrier, dairy products have special importance. Yoghurt is the most popular fermented milk product in the most parts of the world and commercially produced by inoculation of milk with a mixture of Lactobacillus bulgaricus and Streptococcus thermophilus culturesMethods:In the current study viability of bifidobacterium bifidum as a probiotic culture have been surveyed in the yoghurts treated with gelatin, corn starch and inulin in the levels of 0.4 and 0.8% (w/w) at 0, 7, 14 and 21 days of storage intervals. In addition, texture, organoleptic and chemical characteristics of probiotic and commercial yoghurts have been comprised. Viable cells were enumerated by plating diluted samples (peptonized water) on solid MRS agar. Cultures were incubated for 72 h at 37 °C to determine bifidobacterium bifidum populationResults:The results showed that the numbers of bifidobacterium bifidum in the yoghurt samples were 8.59 log cfu/gr at the first day of production. These amounts reached to 5.05 log cfu/gr in control sample (without hydrocolloid) and 6.11, 6.19 and 6.05 log cfu/gr in yoghurts contain inulin, gelatin, corn starch after 21 days of storage time respectively. At the end of 21th day, the number of live probiotic cells were higher than those recommended for beneficial effect in the treated samples.Conclusion:Viability of probiotic bacteria were significantly (P<0.05) higher in yoghurts containing 0.8% hydrocolloids.Therefore gelatin can be used successfully in the production of probiotic yoghurt with bifidobacterium bifidum without any advers effect on quality during storage.

کلیدواژه ها:

Hydrocolloids ، bifidobacterium bifidum ، Yoghurt ، survival