Emergent sources of prebiotics: seaweeds and microalgae

In recent years, scientists have become aware that human microbiota, in general, and gut microbiota, in particular, play a major role in human health and diseases, such as obesity and diabetes, among others. A large number of evidence has come to light regarding the beneficial effects, either for the host or the gut microbiota, of some foods and food ingredients or biochemical compounds. Among these, the most promising seem to be polysaccharides (PS) or their derivatives, and they include the dietary fibers. Some of these PS can be found in seaweeds and microalgae, some being soluble fibers, such as alginates, fucoidans, carrageenans and exopolysaccharides, that are not fermented, at least not completely, by colonic microbiota. This review gives an overview of the importance of the dietary fibers, as well as the benefits of prebiotics, to human health. The potential of the PS from marine macro- and microalgae to act as prebiotics is discussed, and the different techniques to obtain oligosaccharides from PS are presented. The mechanisms of the benefits of fiber, in general, and the types and benefits of algal fibers in human health are highlighted. The findings of some recent studies that present the potential effects of prebiotics on animal models of algal biomass and their extracts, as well as oligo- and polysaccharides, are presented. In the future, the possibility of using prebiotics to modulate the microbiome, and, consequently, prevent certain human diseases is foreseen.info:eu-repo/semantics/publishedVersio

Health applications of bioactive compounds from marine microalgae

Marine microalgae and cyanobacteria are very rich in several chemical compounds and, therefore, they may be used in several biological applications related with health benefits, among others. This review brings the research up-to-date on the bioactive compounds produced by marine unicellular algae, directly or indirectly related to human health. It covers and goes through themost studied applications of substances such as PUFA, sterols, proteins and enzymes, vitamins and pigments, in areas so diverse as human and animal nutrition, therapeutics, and aquaculture. The great potential of marine microalgae and the biocoumpounds they produce are discussed in this review.info:eu-repo/semantics/publishedVersio

On the Utilization of Microalgae for Brewery Effluent Treatment and Possible Applications of the Produced Biomass

The effluent of a brewery, complete or diluted with deionised water or with normal culture medium, was used as the growth nutrient medium for Chlorella vulgaris and for a consortium obtained from the autochthonous flora of that effluent (microalgae, cyanobacteria and bacteria). The cultures were exposed to continuous light and aeration, at 25°C, and growth was evaluated by direct counting (C. vulgaris) or by chlorophyll determination (autochthonous flora). Total protein and lipid content, and amino acid and fatty acid profiles in the produced biomass were determined. The highest removal rate of nutrients present in the effluent was obtained when the complete effluent was used as the culture medium for the autochthonous flora – up to 5,855 g kg–1 biomass d–1 of nitrogen and up to 805 g kg–1 biomass d–1 of phosphate. A reduction of up to 27% in biological oxygen demand (BOD5, initial level of 2,172 mg O2 L–1) and up to 15% in chemical oxygen demand (COD, initial level of 1,340 mg O2 L– 1) was observed in cultures of the autochthonous flora grown in different loads of effluent. A significant increase in aspartic acid, glutamic acid and valine content, and a higher level of the ramified fatty acids, of the 14:0isobr, 18:4ω3, and the eicosapentaenoic acid, were found in the final biomass obtained from cultures grown with different loads of effluent, compared with the results obtained for the cultures grown in normal nutrient medium. The final microalgae biomass obtained, considering its protein and fatty acid content and the absence of heavy metals in significant amount, can be appropriate for use as animal feed or for biofuel production.info:eu-repo/semantics/publishedVersio

Cinnamomum burmannii decoction: a thickening and flavouring ingredient

Cinnamon is a spice widely used as a flavouring agent in foodstuffs. Despite its commercial availability and low cost, C. burmannii aqueous extracts obtained by decoction originate high viscous solutions (1545 cP) when compared with C. verum (51 cP), preventing its broad use by food industry. Following the hypothesis that cinnamon polysaccharides are responsible for this viscosity, in this work, the hot water-soluble polysaccharides from C. burmannii were structurally characterized, using C. verum for comparison. The results showed that C. burmannii had a higher content of branched arabinoxylans in relation to C. verum. The hot water-soluble polysaccharides from C. verum comprised also glucans, arabinogalactans, and pectic polysaccharides. The partial mild acid-hydrolysis performed to C. burmannii allowed to reach a viscosity value near to the C. verum solutions, keeping the characteristic aroma profile of cinnamon by the predominance of cinnamaldehyde and other varietal compounds, namely mono and sesquiterpenoids. Therefore, C. burmannii can be used as flavouring and thickening agent, whereas low viscosity products can be obtained by a partial acid-hydrolysis, contributing to its wide application in food industry.publishe

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved