Incorporation of citrus fibers in fermented milk containing probiotic bacteria.

The incorporation of Lactobacillus acidophilus CECT 903, Lactobacillus casei CECT 475 and Bifidobacterium bifidum CECT 870 together with lemon (LF) and orange (OF) fibers obtained from juice by-products were tested in (i) a model system: fiber enriched with de Man Rogosa Sharp (MRS) broth cultured with each probiotic bacteria and (ii) evaluation of populations of probiotic bacteria in fermented milks formulated with citrus fibers. Citrus fibers enhanced L. acidophilus CECT 903, and L. casei CECT 475 survival in MRS during refrigerated storage, whereas erratic results were obtained for B. bifidum CECT 870, OF enhanced its growth and LF had inhibitory effect. Populations of probiotic bacteria decreased with storage time in MRS broth. The presence of yogurt starter bacteria in probiotic fermented milks favored the growth and survival of L. acidophilus and B. bifidum. Citrus fiber presence in fermented milks also enhanced bacterial growth and survival of the tested probiotic bacteria. This study indicates that citrus fiber enriched fermented milk have good acceptability and are good vehicles for a variety of commercial probiotics but survival of B. bifidum will need to be improved.