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Cholesterol-lowering activity is one of the most promising properties of lactic acid bacteria with probiotic characteristics. In the present study, 58 potentially probiotic lactic acid bacteria were tested for their ability to survive in vitro digestion and reduce cholesterol in a medium containing cholesterol and bile acids. The best-performing strains (Lactobacillus casei VC199, Lactobacillus paracasei ssp. paracasei SE160 and VC213, Lactobacillus plantarum VS166 and VS513, Enterococcus faecium VC223, and Enterococcus lactis BT161) resulted in a 42 to 55% reduction of the cholesterol level in broth and were further tested in cheese manufacture. The cholesterol content in all the cheeses decreased with ripening. All the strains were present in the cheese at levels higher than 10 cfu/g until 60 d of ripening, the highest reductions (up to 23%) being obtained when Lb. paracasei ssp. paracasei VC213 and E. lactis BT161 were added during the cheese-making. The adjunct cultures had no negative effect on the sensory characteristics of the cheese. Thus, these strains with proven in vitro properties are good candidates for novel probiotic-containing formulations and could be used to functionalize foods such as dairy fermented products.

Sustainable exploitation of agro-industrial by-products has attracted great interest in cereal bran valorization. In this research, a polyphasic approach has been carried out to characterize maize bran at microbiological and chemical level during a sourdough like fermentation process, in order to enhance its technological and nutritional properties. Autochthonous microbiota was isolated at different refreshment steps and subjected to identification and molecular characterization. Fermentation was characterized by a rapid increase in lactic acid bacteria and yeasts, with a co-dominance, at the initial stage, of Weissella spp., Pediococcus spp. and Wickerhamomyces anomalus. At the end of the fermentation, a natural selection was produced, with the prevalence of Lactobacillus plantarum, Lactobacillus brevis and Kazachstania unispora. This is the first time that a specific association between LAB and yeasts is reported, during the maize bran fermentation process. Enzymatic activities related to this microbial consortium promoted a “destructuration” of the fiber fraction, an increase in soluble dietary fiber and a reduction of phytic acid content. Our data also evidenced a noticeable increment in ferulic acid. The results obtained indicate that fermentation processes represent an efficient biotechnological approach to increase nutritional and functional potential of maize bran. Moreover, the characterization of microbiota involved in natural fermentation process will allow the selection of specific biotypes, with appropriate metabolic and enzymatic activities, to conduct “tailored” fermentation processes and improve brans or whole-meal flours from both nutritional and technological points of view.

Cereal Chem. 91(4):342-349Several studies have emphasized the possibility of enhancing nutritional properties of cereal by-products through biotechnological processes. Bran fermentation positively affects the bioavailability of several functional compounds. Moreover, bran fermentation could increase water-extractable arabinoxylans (WEAX), compounds with positive effects on glucose metabolism and prebiotic properties. This study was aimed at increasing the amount of bran bioactive compounds through a sourdoughlike fermentation process. Wheat bran fermentations were conducted through continuous propagation by back-slopping of fermented bran (10% inoculum) until a stable microbiota was established, reaching high counts of lactic acid bacteria and yeasts (10 9 and 10 7 CFU/g, respectively). At each refreshment step, bacterial strains were isolated, clustered, molecularly analyzed by randomly amplified polymorphic DNA, and identified at the species level by 16S rRNA gene sequencing. Leuconostoc mesenteroides, Lactobacillus brevis, Lactobacillus curvatus, Lactobacillus sakei, Lactobacillus plantarum, Pediococcus pentosaceus, and Pichia fermentans dominated the stable sourdough ecosystem. After fermentation, levels of soluble fiber increased (+30%), and WEAX and free ferulic acid were respectively fourfold and tenfold higher than in raw bran, results probably related to microbial xylan-degrading activity, whereas phytic acid was completely degraded. These preliminary data suggest that fermented bran could be considered an interesting functional ingredient for nutritional enhancement.