Characteristics of bifidobacterial conjugated fatty acid and hydroxy fatty acid production and its potential application in fermented milk

This is the first study to elucidate bifidobacterial conjugated fatty acid and hydroxy fatty acid production as well as its potential in fermented milk. One hundred and fifty-two bifidobacteria belonging to seven species were assayed in this study. The results showed that only Bifidobacterium breve (B. breve), Bifidobacterium longum (B. longum), Bifidobacterium pesudocatenulatum (B. pseudocatenulatum) and Bifidobacterium dentium (B. dentium) generated CLA and CLNA, while nearly all the strains could convert free LA into 10-HOE. B. breve showed the highest CLA- and CLNA-generation ability (the highest conversion rate, 90.1%, for B. breve CCFM683), while B. pseudocatenulatum revealed higher 10-HOE-producing ability. Further study demonstrated that 10-HOE competition could influence the CLA generation in Bifidobacterium. Furthermore, B. breve CCFM683, as the highest CLA- and CLNA-producer, could increase the content of CLA and CLNA to 0.14 mg/mL and 0.065 mg/mL in fermented milk, presenting as a potentially ideal starter culture increasing conjugated fatty acid contents in milk.