Viability of bifidobacteria in commercial yogurt products in North Carolina

Fifty-eight commercial yogurt products from local stores containing bifidobacteria in addition to the traditional yogurt culture were evaluated for the viability of bifidobacteria and yogurt starter culture. Our results indicated that the starter culture counts in individual samples for L. bulgaricus and S. thermophilus, respectively, ranged from 6.63 to 9.42 and 0.0 to 9.36 log cfu/ml. The counts for bifidobacteria varied among the tested samples ranging from 0.0 to 6.0 log cfu/ml in individual samples. Of the 58 products claiming the inclusion of bifidobacteria in their product, 44 (76 %) were found to contain viable cultures. The populations of bifidobacteria were at or below 6.0 log cfu/ml in all tested products, below recommended levels for beneficial health effects. North Carolina's regulation on viable probiotic bacterial counts should be more restrictive to ensure that products deliver a sufficient amount of viable bifidobacteria.