Seaweeds, i.e. macroalgae that occupy the littoral zone, are a great source of compounds with diverse applications; their types and content greatly determine the potential applications and commercial values. Algal polysaccharides, namely the hydrocolloids: agar, alginate and carrageenan, as well as other non-jellifying polysaccharides and oligosaccharides, are valuable bioproducts. Likewise, pigments, proteins, amino acids and phenolic compounds are also important, exploitable compounds. For the longest time the dominant market for macroalgae has been the food industry. More recently, several other industries have increased their interest in algal-derived products, e.g. cosmetics, pharmaceuticals and more recently, as a source of feedstock for biorefinery applications. This manuscript reviews the chemical composition of dominant macroalgae, as well as their potential added-value products and applications. Particular attention is devoted to the macroalgal species from the Iberian Peninsula. This is located in the Southwest of Europe and is influenced by the distinct climates of the Mediterranean Sea and the Atlantic Ocean, representing a rich spot of marine floral biodiversity.
Fucoidan is a sulfated polysaccharide found in brown seaweed. Due to its reported biological activities, including antiviral, antibacterial and anti-inflammatory activities, it has garnered significant attention for potential biomedical applications. However, the direct relationship between fucoidan extracts’ chemical structures and bioactivities is unclear, making it extremely challenging to predict whether an extract will possess a given bioactivity. This relationship is further complicated by a lack of uniformity in the recent literature in terms of the assessment and reporting of extract properties, yield and chemical composition (e.g., sulfate, fucose, uronic acid and monosaccharide contents). These inconsistencies pose significant challenges when directly comparing extraction techniques across studies. This review collected data on extract contents and properties from a selection of available studies. Where information was unavailable directly, efforts were made to extrapolate data. This approach enabled a comprehensive examination of the correlation between extraction techniques and the characteristics of the resulting extracts. A holistic framework is presented for the selection of fucoidan extraction methods, outlining key heuristics to consider when capturing the broader context of a seaweed bioprocess. Future work should focus on developing knowledge within these heuristic categories, such as the creation of technoeconomic models of each extraction process. This framework should allow for a robust extraction selection process that integrates process scale, cost and constraints into decision making. Key quality attributes for biologically active fucoidan are proposed, and areas for future research are identified, such as studies for specific bioactivities aimed at elucidating fucoidan’s mechanism of action. This review also sets out future work required to standardize the reporting of fucoidan extract data. Standardization could positively enhance the quality and depth of data on fucoidan extracts, enabling the relationships between physical, chemical and bioactive properties to be identified. Recommendations on best practices for the production of high-quality fucoidan with desirable yield, characteristics and bioactivity are highlighted.
Every year million tons of by-products and waste from olive and orange processing are produced by agri-food industries, thus triggering environmental and economic problems worldwide. From the perspective of a circular economy model, olive leaves and orange peels can be valorized in valuable products due to the presence of bioactive compounds such as polyphenols exhibiting beneficial effects on human health. The aqueous extracts of olive leaves and orange peels rich in phenolic compounds were prepared by ultrasound-assisted extraction. Both extracts were characterized in terms of yield of extraction, total phenolic content and antioxidant capacity; the polyphenolic profiles were deeper investigated by HPLC-MS analysis. Each extract was included in liposomes composed by a natural phospholipid, 1,2-dioleoyl-sn-glycero-3-phosphocholine,and cholesterol prepared according to the thin-layer evaporation method coupled with a sonication process. The antimicrobial activity of the extracts, free and loaded in liposomes, was investigated according to the broth macrodilution method against different strains of potential bacterial pathogenic species: Staphylococcus aureus (NCIMB 9518), Bacillus subtilis (ATCC 6051) and Enterococcus faecalis (NCIMB 775) as Gram-positive, while Escherichia coli (NCIMB 13302), Pseudomonas aeruginosa (NCIMB 9904) and Klebsiella oxytoca (NCIMB 12259) as Gram-negative. The encapsulation of olive leaves extract in liposomes enhanced its antibacterial activity against S. aureus by an order of magnitude.
9 March 2021 in Journal of Cancer Metastasis and Treatment
Journal of Cancer Metastasis and Treatment is an open access journal, focusing on basic and clinical studies related to cancer cell, cell biology, oncology, radiation therapy and radiology, obstetrics and gynecology, pediatrics, surgery, hematology, neuro-oncology, etc.
28 May 2019 in Journal of Oceanology and Limnology
There are known culinary applications of halophytes species, such as Atriplex halimus, Portulaca oleracea, Beta maritima, Salicornia europaea and Arthrocnemum macrostachyum, mostly due to their mineral content, as they provide an alternative to common salt. Species of the last two genera possess a curious salt resistance mechanism, in which they can store Na+ in vacuoles in their shoots, using these vacuoles to stimulate growth. It is theorized that this mechanism enables the extraction of a vegetable salt, with a different Na+/Cl- ratio , providing healthier applications for human consumption, due to lower Na+ levels. In the present work we try to validate an efficient method for extracting a vegetable salt from a commercial mixture of Salicornia europaea and Salicornia bigelovii, as well as wild Arthrocnemum macrostachyum. We compared the efficiency of two extraction solvents used on this methodology. The used process presented mean yield rates around 70% (Salicornia) and 50% (Arthrocnemum). The comparison of the results between genera was the expected, since Salicornia species are more succulent than Arthrocnemum. This method yield rates in Salicornia appear to be higher than the expected based on previous publication. The data suggests other elements of interest may be differently distributed between the two genera. A nutritional profile, which we intend to do, may elucidate about the contents of vegetable salt.