Application of conjugated linoleic acid-producing strain, Bifidobacterium breve JKL2022, in the development of probiotic dairy products

With the rising interest in functional foods, several studies have developed food products with additional health benefits, particularly through supplementation with probiotics. The present study assessed the potential of Bifidobacterium breve JKL2022 as a probiotic adjunct culture in dairy products. Preliminary experiments on the capacity of JKL2022 to grow and produce conjugated linoleic acid (CLA) in dairy products were performed using 10% reconstituted skim milk (RSM). Thereafter, the survivability of B. breve JKL2022 in three dairy products (whole milk, yogurt, and cream cheese) and its biochemical effects on each product were investigated. The results revealed that the growth, fermentation, and CLA production of B. breve JKL2022 were significantly enhanced in 10% RSM supplemented with either 0.1% yeast extract or 0.1% yeast extract with 2.0% glucose compared with those of the control. Additionally, JKL2022 remained viable above the minimum probiotic standard (> 10⁶ CFU/mL) in whole milk and cream cheese during 15 d of refrigerated storage. The viability of B. breve JKL2022 was greater in yogurts supplemented with glucose, inulin, and trans-galactooligosaccharides than in the control. However, it exhibited the lowest survivability (range: 2.26–4.55 log CFU/mL) in yogurt after 15 d of refrigerated storage, indicating the sensitivity of B. breve JKL2022 to acidic conditions. Overall, this study suggests that developing probiotic or CLA-enhanced dairy products using B. breve JKL2022 is possible. In particular, it is reasonably suitable for developing probiotic cheeses that have a high pH and buffering capacity.