Production of free fatty acids and conjugated linoleic acid in probiotic dahi containing Lactobacillus acidophilus and Lactobacillus casei during fermentation and storage

The production of free fatty acids (FFAs) and conjugated linoleic acid (CLA) in probiotic dahi containing Lactobacillus acidophilus and L. casei during fermentation and 10 d of storage at 4 °C was evaluated and compared with control dahi. The total FFAs in terms of acid degree values significantly increased during fermentation and storage of both types of dahi samples. In addition, gas chromatographic analysis of FFAs showed that butyric and linoleic acids increased in the probiotic dahi compared to control dahi during fermentation and storage. Furthermore, the CLA content increased in probiotic dahi during fermentation and remained stable during storage, whereas no change was observed in the control dahi. Probiotic lactobacilli appeared to increase the production of FFAs by lipolysis of milk fat, and produced CLA by using internal linoleic acid, which may confer nutritional and therapeutical value to the product.