Comparation of probiotic properties of Lactobacillus casei Zhang, a new probiotic, with selected probiotic strains.

The probiotic properties of L.casei Zhang was assayed and compared with four selected commercial probiotics: L.acidophilus NCFM,L.rhamnosus GG,L.casei Shirota and Bifidobacterium animalis Bb12.The fermented milk inoculated with L.casei Zhang showed higher pH and lower TA than those of the samples inoculated with the other selected probiotics during the fermentation process.The refrigerated storage resulted in decreases in pH and increases in TA of the fermented milk of L.casei Zhang,while the fermentation in the other samples slowed down.The proteolytic activity of L.casei Shirota and Bifidobacterium animalis Bb12 gradually decreased during the refrigerated storage,while the proteolytic activity of L.casei Zhang,L.acidophilus NCFM and L.rhamnosus GG continued to increase.Although L.casei Zhang grow more slowly in milk than L.acidophilus NCFM and L.casei Shirota,the yogurt samples fermented with L.casei Zhang exhibited higher viable count than those made with the other probiotic strains during storage.L.casei Zhang showed good potential for application in functional foods and health-related products.