In vitro prebiotic effects of seaweed polysaccharides

Although prebiotic activities of alginate and agar oligosaccharides isolated from seaweeds have been reported, it remains unknown whether seaweed polysaccharides have prebiotic activity. In this study, we isolated polysaccharides from four species of seaweeds, such as Grateloupia fi licina(GFP), Eucheuma spinosum(ESP), Ulva pertusa(UPP), and A scophyllum nodosum(ANP), and characterized their structures and prebiotic ef fects in vitro. The results showed that these polysaccharides were dif ferent in total sugar and sulfate contents as well as monosaccharide composition. GFP and ESP significantly promoted bifi dobacterium proliferation and 0.1% ESP and 0.4% GFP resulted in the highest proliferation rates of beneficial bacteria, whereas UPP and ANP inhibited the growth of beneficial bacteria at all tested concentrations(0.1%–0.5%). The different behaviors of the four seaweed-originated polysaccharides might be refl ected by differences in monosaccharide composition and structure. Therefore, polysaccharides isolated from GFP and ESP could be utilized as prebiotics. However, more studies must be carried out in vivo.

Study on prebiotic effectiveness of neutral garlic fructan in vitro

Garlic is traditionally believed to have many health benefits including prevention of gastrointestinal diseases.One of the major components,garlic fructan(GF),was evaluated for its prebiotic effectiveness on human intestinal microflora.Garlic fructans A(DP 16)and B(DP 21)were prepared by ethanol fractionation precipitation.Then,they were added to an in vitro fermentation system as the sole carbon source inoculated with human fecal suspension.The total anaerobic bacteria,Bacteroides and Bifidobacteria,were enumerated by plate counting on selective media.Terminal restriction fragment length polymerization(tRFLP)was used to analyze DNA extracted from the in vitro cultures.The results indicated that the log CFUs of both Bacteroides(GF A 6.96,GF B 7.15)and Bifidobacteria(GF A 7.74,GF B 7.74)grown in the GF cultures at 24 h were significantly higher than those at 0 h(Bacteroides 4.93,Bifidobacteria 4.78)(P<0.05).Terminal restriction fragments(TRFs)256–258 bp(ascribed to Bifidobacterium)in the profiles were also observed higher in the TRFLP profiles from the garlic fructans’cultures.In this study,GFs were found to selectively stimulate the growth of beneficial Bifidobacteria from human fecal microflora.The prebiotic effectiveness of GFs supports the use of garlic as a way to prevent some gastrointestinal diseases.©2013 Beijing Academy of Food Sciences.Production and hosting by Elsevier B.V.All rights reserved.

Some Properties of Bio-Yogurt Enriched with Cellulose Fiber

In this study, bio-yogurts, which contain L. acidophilus and Bifidobacterium animalis subsp. lactis, were produced with cellulose fiber (CF) addition at a various level (0%, 0.5%, 1% and 2%) and stored at 4°C ± 1°C for 20 days. Bio-yogurts were analysed 1, 10 and 20 days after production. The storage period significantly influenced overall properties of the samples. Addition of CF has positively affected the physical and textural properties of yoghurt, such as serum separation, water holding capacity, viscosity, firmness, adhesiveness, cohesiveness, springiness, gumminess and chewiness (p < 0.05). It also slightly stimulated the development of probiotic bacteria (p < 0.05). Bio-yogurt, which contains 0.5% CF in sensory aspect, is the most appreciated.

Impact of simulated in vitro gastrointestinal digestion on bioactive compounds,bioactivity and cytotoxicity of melon (Cucumis melo L. inodorus) peel juice powder

The objectives of this research work were to evaluate the effect of in vitro gastrointestinal digestion (GIT) on melon peel juice (MPJ) powder from fruit processing industry by-products,considering (i) the recovery and accessibility indexes,(ii) the changes on antioxidant activity,and (iii) the prebiotic effect.Throughout exposition to GIT conditions a decrease on the total phenolic content (TPC = 65.31%) and antioxidant activity by ABTS = 39.77% and DPPH = 45.91% were observed.However,these both parameters exhibited stable accessibility,accounting with 81.89%,76.55%,and 54.07% for TPC,ABTS and DPPH,respectively.After gastrointestinal digestion,the non-absorbed fraction exhibited a positive impact on the growth of Bifidobacterium and Lactobacillus strains,possibly associated with the high content of simple sugar (glucose and fructose).This fraction also showed to be safe on Caco-2 intestinal cells.These findings suggest that MPJ might be used as a potential food functional ingredient.