Hydrothermal extraction of ulvans from Ulva spp. in a biorefinery approach.

A simple cascade process based on the hydrothermal fractionation of Ulva spp. biomass was proposed. Considering the overall extraction yields (50 %), ulvan recovery (23 %), and ulvan composition, structural, mechanical and cytotoxic properties, the selected optimal final heating temperature was 160 °C. Ethanol precipitation provided the highest ulvan recovery yields but choline chloride precipitated ulvans showed stronger mechanical properties, G´ moduli 1.5·104 Pa and 3·104 Pa for ethanol and for choline chloride, respectively. Both products were safe on NCTC 929 mouse fibroblasts and after a cooling stage, formed films without requiring any additives. From the ulvan-free liquid fraction, one product with 43 % (wt, d.b.) phenolics and moderate antiradical properties and a byproduct containing nutrients and minerals were separated. The methane potential of the corresponding residual solids was influenced by the hydrothermal heating temperature and was doubled compared to than for the untreated seaweed biomass (60 mL/g VS). This scheme could be also applied to the wet algal biomass, in a chemical free alternative to provide ready to use ulvan biopolymers, bioactives, nutrients, salts and biogas, conforming a biorefinery approach.

Green Extraction of Antioxidant Fractions from Humulus lupulus Varieties and Microparticle Production via Spray-Drying.

The formulation of polymeric microparticles to encapsulate bioactive compounds from two hop varieties (Nugget and Perle) using sequential green extraction processes was performed. The technologies used were ultrasound-assisted extraction (UAE) and pressurized hot water (PHW) extraction. Liquid phases were analyzed for total phenolic content (~2%), antioxidant activity (IC50, DPPH: 3.68 (Nugget); 4.46 (Perle) g/L, TEAC (~4-5%), FRAP (~2-3%), and reducing power (~4%)), protein content (~1%), oligosaccharide content (~45%), and for structural features. The fractions obtained from UAE were selected to continue with the drying process, achieving the maximum yield at 120 °C (Perle) and 130 °C (Nugget) (~77%). Based on these results, the formulation of polymeric microparticles using mannitol as the carrier was performed with these fractions. The production yield (~65%), particle size distribution (Perle: 250-750 µm and Nugget: ~100 µm), and rheological features (30-70 mPa s at 0.1 s-1) were the parameters evaluated. The UAE extracts from hop samples processed using a sustainable aqueous treatment allowed the formulation of microparticles with a suitable yield, and morphological and viscosity properties adequate for potential food and non-food applications.

Microwave-Assisted Hydrothermal Processing of Rugulopteryx okamurae.

One possible scheme of Rugulopteryx okamurae biomass valorization based on a green, rapid and efficient fractionation technique was proposed. Microwave-assisted pressurized hot water extraction was the technology selected as the initial stage for the solubilization of different seaweed components. Operation at 180 °C for 10 min with a 30 liquid-to-solid ratio solubilized more than 40% of the initial material. Both the alginate recovery yield (3.2%) and the phenolic content of the water-soluble extracts (2.3%) were slightly higher when distilled water was used as solvent. However, the carbohydrate content in the extract (60%) was similar for both solvents, but the sulfate content was higher for samples processed with salt water collected from the same coast as the seaweeds. The antiradical capacity of the extracts was related to the phenolic content in the extracts, but the cytotoxicity towards HeLa229 cancer cells was highest (EC50 = 48 µg/mL) for the extract obtained with distilled water at the lowest temperature evaluated. Operation time showed a relevant enhancement of the extraction performance and bioactive properties of the soluble extracts. The further fractionation and study of this extract would be recommended to extend its potential applications. However, due to the low extraction yield, emphasis was given to the solid residue, which showed a heating value in the range 16,102-18,413 kJ/kg and could be useful for the preparation of biomaterials according to its rheological properties.

Characterization of the Antiproliferative Activity of Sargassum muticum Low and High Molecular Weight Polysaccharide Fractions.

The extract obtained by pressurized hot water extraction from Sargassum muticum, to recover the bioactive compound known as fucoidan, was fractionated using membranes of 100, 50, 30, 10, and 5 kDa, obtaining five retentates and the final permeate. These fractions were characterized for phloroglucinol content, protein content, sulfate content, and trolox equivalent antioxidant capacity (TEAC); apart from oligosaccharides, FTIR and molar mass distribution were also evaluated. Retentates of 100 and 50 kDa showed higher values for phloroglucinol, TEAC, and sulfate content. The rheology of the alginate fraction was also evaluated. Regarding the potential antitumoral activity, all fractions were assessed in MCF-7 cells using a metabolic activity assay based on the reduction of a tetrazolium compound, the most efficient being R100 and R50. Based on the results, these fractions were compared with commercial fucoidans at the same concentrations, and similar results were found. In addition, synergistic cytotoxic effects using two drugs commonly used in breast cancer, cis-Platinum (cis-Pt) and 5-fluorouracil (5-FU), were tested in combination with R100 and R50. Promising results were obtained when the retentate and the drugs were mixed, showing an improvement in the cytotoxicity induced by the chemotherapy.

In Vitro Study of the Therapeutic Potential of Brown Crude Fucoidans in Osteoarthritis Treatment.

Osteoarthritis, one of the most common joint degenerative pathologies, still has no cure, and current treatments, such as nonsteroidal anti-inflammatory drugs, can cause serious adverse effects when taken for a long time. Brown seaweed crude fucoidans are used for the clinical treatment of several pathologies. In this study, the therapeutical potential of these biocompounds was analyzed in primary chondrocytes and the 260TT human chondrocyte cell line. Crude fucoidan from Undaria pinnatifida (Up) and Sargassum muticum (Sm) was obtained by different extraction techniques (microwave-assisted extraction, pressurized hot-water extraction, ultrasound-assisted extraction) and chemically and structurally characterized by Fourier transform infrared spectroscopy, high-performance size-exclusion chromatography, proton nuclear magnetic resonance, and scanning electron microscopy. Once cell viability was confirmed in chondrocytes treated with crude fucoidans, we evaluated their anti-inflammatory effects, observing a significant reduction in IL-6 production stimulated by IL-1ß. Findings were confirmed by analysis of IL-6 and IL-8 gene expression, although only fucoidans from Up achieved a statistically significant reduction. Besides this, the antioxidant capacity of crude fucoidans was observed through the upregulation of Nrf-2 levels and the expression of its transcriptional target genes HO-1 and SOD-2, with compounds from Up again showing a more consistent effect. However, no evidence was found that crude fucoidans modulate senescence, as they failed to reduced ß-galactosidase activity, cell proliferation, or IL-6 production in chondrocytes stimulated with etoposide. Thus, the findings of this research seem to indicate that the tested crude fucoidans are capable of partially alleviating OA-associated inflammation and oxidative stress, but fail to attenuate chondrocyte senescence.

Green Extraction of Carrageenans from Mastocarpus stellatus.

The recovery of biopolymers from natural resources using eco-friendly extraction technologies that enhance their mechanical properties has gained attention in recent years. In this context, this work deals with the isolation of hybrid carrageenans from Mastocarpus stellatus red seaweed using subcritical water extraction operating in a wide range of thermal conditions (70-190 °C). The extracted biopolymers were analyzed by means of either Fourier-Transform infrared, nuclear magnetic resonance, rheological or cell viability assays. In parallel, the fundamental chemical composition of the seaweed used as raw material, as well as the main phytochemical properties of the soluble liquid extracts, were also studied. Results indicated that thermal extraction conditions significantly affected the rheological behavior of the recovered hybrid carrageenans. The hybrid carrageenan extraction yields varied, with results between 10.2 and 30.2% being the highest values obtained at hydrothermal treatment of 130 °C. A wide palette of viscous features was identified for recovered hybrid carrageenans, with the strongest rheology properties observed at the same temperature. It should be remarked that the maximum inhibitory effect was also obtained at 130 °C for both the ovarian carcinoma cell line (A2780) (65%, IC50: 0.31 mg/mL) and lung carcinoma cell line (A549) (59%, IC50: 0.41 mg/mL).

Antifibrotic effect of brown algae-derived fucoidans on osteoarthritic fibroblast-like synoviocytes.

Synovial fibrosis is a pathological process which contributes to joint pain and stiffness in several musculoskeletal disorders. Fucoidans, sulfated polysaccharides found in brown algae, have recently emerged as promising therapeutic agents. Despite the increasing amount of evidence suggesting the protective role of fucoidans in different experimental approaches of human fibrotic disorders, the effect of these sulfated polysaccharides on synovial fibrosis has not been investigated yet. By an in vitro experimental approach in fibroblast-like synoviocytes, we detected that fucoidans inhibit their differentiation into myofibroblasts with tumor cell-like characteristics and restore apoptosis. Composition and structure of fucoidan appear to be critical for the detected activity. Furthermore, protective effects of these sulfated polysaccharides are mediated by upregulation of nitric oxide production and modulation of TGF-ß/smad pathway. Altogether, our results support the use of fucoidans as therapeutic compounds in the treatment of the fibrotic processes involved in rheumatic pathologies.

Pressurized Hot Water Extraction and Bio-Hydrogels Formulation with Aristotelia chilensis [Mol.] Stuntz Leaves.

Aristotelia chilensis is a plant rich in phenolics and other bioactive compounds. Their leaves are discarded as waste in the maqui berry industry. A new application of these wastes is intended by the recovery of bioactive compounds using pressurized hot water extraction with conventional or microwave heating. Both technologies have been selected for their green character regarding the type of solvent and the high efficiency in shorter operation times. Extractions were performed in the temperature range 140-200 °C with a solid/liquid ratio of 1:15 (w:w). The extracts' total phenolic content, antioxidant capacity, and saccharides content obtained with both heating methods were measured. Additionally, the thermo-rheological properties of the gelling matrix enriched with these extracts were analyzed. Optimum conditions for lyophilized extracts were found with conventional heating, at 140 °C and 20 min extraction; 250.0 mg GAE/g dry extract and 1321.5 mg Trolox/g dry extract. Close to optimum performance was achieved with microwave heating in a fraction of the time (5 min) at 160 °C (extraction), yielding extracts with 231.9 mg GAE/g dry extract of total phenolics and antiradical capacity equivalent to 1176.3 mg Trolox/g dry extract. Slightly higher antioxidant values were identified for spray-dried extracts (between 5% for phenolic content and 2.5% for antioxidant capacity). The extracts obtained with both heating methods at 200 °C contained more than 20% oligosaccharides, primarily glucose. All the formulated gelling matrices enriched with the obtained extracts displayed intermediate gel strength properties. The tested technologies efficiently recovered highly active antioxidant extracts, rich in polyphenolics, and valuable for formulating gelling matrices with potential applicability in foods and other products.

Applying Seaweed Compounds in Cosmetics, Cosmeceuticals and Nutricosmetics.

The interest in seaweeds for cosmetic, cosmeceutics, and nutricosmetics is increasing based on the demand for natural ingredients. Seaweeds offer advantages in relation to their renewable character, wide distribution, and the richness and versatility of their valuable bioactive compounds, which can be used as ingredients, as additives, and as active agents in the formulation of skin care products. Bioactive compounds, such as polyphenols, polysaccharides, proteins, peptides, amino acids, lipids, vitamins, and minerals, are responsible for the biological properties associated with seaweeds. Seaweed fractions can also offer technical features, such as thickening, gelling, emulsifying, texturizing, or moistening to develop cohesive matrices. Furthermore, the possibility of valorizing industrial waste streams and algal blooms makes them an attractive, low cost, raw and renewable material. This review presents an updated summary of the activities of different seaweed compounds and fractions based on scientific and patent literature.

Valorization of Arnica montana Wastes after Extraction of the Ethanol Tincture: Application in Polymer-Based Matrices.

The waste solids remaining after the ethanolic extraction of arnica were proposed as raw material for the recovery of the remaining phenolic fraction. Greener processes based on intensification extraction, with microwave (MHG) and ultrasound (UAE) assistance and pressurized hot water extraction under subcritical conditions (AH), were studied. The entire process provided approximately 28% of phenolics for the sequence when MHG was used, 22% in the sequence where AH was employed, and the extracts showed up to 60% the ABTS radical scavenging capacity of Trolox. However, the cytotoxic effects on the cell growth of tumoral cells were only moderate. Therefore, considering a possible external topical application, extracts containing selected arnica extracts were further used to develop polymer-based gelled matrices formulated with either chitosan or polyvinyl alcohol. Rheological testing indicated that all proposed matrices exhibited relatively high mechanical features, even better than those determined with matrices prepared with their counterpart commercial arnica tinctures. Overall, the shear-thinning behavior of gelled matrices loaded with arnica extracts obtained by MHG or AH stages was enhanced compared to those containing ethanolic extracts, whereas the viscoelastic features became smoother for polymeric matrices incorporated with arnica extracts recovered at the highest MHG irradiation powers or at the highest set point temperatures of AH treatments.

Functional Features of Alginates Recovered from Himanthalia elongata Using Subcritical Water Extraction.

Subcritical water extraction of Himanthalia elongata and the subsequent acetone fractionation to precipitate crude fucoidans generated a liquid phase which was used to recover alginates with a wide range of viscoelastic features and other soluble extracts with potential biological activities. The precipitated alginate was converted to sodium alginate using an environmentally friendly treatment before being characterized by Fourier transform infrared attenuated total reflectance, nuclear magnetic resonance, high performance size exclusion chromatography and rheological measurements. The cell viability of three human cell lines (A549, HCT-116, T98G) in the presence of the extracts obtained before and after acetone fractionation was assessed. Fractionation with different acetone volumes showed a slight effect in the behavior of the different tested cell lines. Results also indicated a notable effect of the processing conditions on the block structure and molar mass of the extracted biopolymer, with the subsequent impact on the rheological properties of the corresponding gelled matrices.

Ultrasound-Assisted Water Extraction of Mastocarpus stellatus Carrageenan with Adequate Mechanical and Antiproliferative Properties.

Ultrasound-assisted water extraction was optimized to recover gelling biopolymers and antioxidant compounds from Mastocarpus stellatus. A set of experiments following a Box-Behnken design was proposed to study the influence of extraction time, solid liquid ratio, and ultrasound amplitude on the yield, sulfate content, and thermo-rheological properties (viscoelasticity and gelling temperature) of the carrageenan fraction, as well as the composition (protein and phenolic content) and antiradical capacity of the soluble extracts. Operating at 80 °C and 80 kHz, the models predicted a compromise optimum extraction conditions at ~35 min, solid liquid ratio of ~2 g/100 g, and ultrasound amplitude of ~79%. Under these conditions, 40.3% carrageenan yield was attained and this product presented 46% sulfate and good mechanical properties, a viscoelastic modulus of 741.4 Pa, with the lowest gelling temperatures of 39.4 °C. The carrageenans also exhibited promising antiproliferative properties on selected human cancer cellular lines, A-549, A-2780, HeLa 229, and HT-29 with EC50 under 51.9 µg/mL. The dried soluble extract contained 20.4 mg protein/g, 11.3 mg gallic acid eq/g, and the antiradical potency was equivalent to 59 mg Trolox/g.

Multi-response optimal hot pressurized liquid recovery of extractable polyphenols from leaves of maqui (Aristotelia chilensis [Mol.] Stuntz).

Multi-response optimization of hot pressurized liquid extraction (HPLE) was applied for the first time to obtain maqui (Aristotelia chilensis [Mol.] Stuntz) leaf extracts. The total polyphenol content (TPC), the antioxidant capacity (AC) as well as the total polyphenol purity of the maqui leaf extracts were accurately predicted (RSD < 8%) at the evaluated extraction scales. The optimum HPLE conditions that prioritized TPC and AC equally (OPT1) recovered ~3 times more TPC (205.14 mg GAE/g leaves) than maqui leaf extracts obtained by maceration, while the extract that prioritized purity over TPC and AC presented the highest purity (36.29%) and an EC50 ~3 times lower than currently reported values. It was found by multi-response optimization that maqui leaves and HPLE are among the best natural sources and extraction techniques, respectively, to recover protocatechuic acid, quercetin, and catechin.

Bioactive Properties of Marine Phenolics.

Phenolic compounds from marine organisms are far less studied than those from terrestrial sources since their structural diversity and variability require powerful analytical tools. However, both their biological relevance and potential properties make them an attractive group deserving increasing scientific interest. The use of efficient extraction and, in some cases, purification techniques can provide novel bioactives useful for food, nutraceutical, cosmeceutical and pharmaceutical applications. The bioactivity of marine phenolics is the consequence of their enzyme inhibitory effect and antimicrobial, antiviral, anticancer, antidiabetic, antioxidant, or anti-inflammatory activities. This review presents a survey of the major types of phenolic compounds found in marine sources, as well as their reputed effect in relation to the occurrence of dietary and lifestyle-related diseases, notably type 2 diabetes mellitus, obesity, metabolic syndrome, cancer and Alzheimer's disease. In addition, the influence of marine phenolics on gut microbiota and other pathologies is also addressed.

Hydrothermal Processing of Laminaria ochroleuca for the Production of Crude Extracts Used to Formulate Polymeric Nanoparticles.

A green extraction process using only water was proposed for the simultaneous extraction of alginate and bioactive compounds from Laminaria ochroleuca. Operation was carried out during non-isothermal heating up to maximal temperatures over the range of 70 °C to 100 °C. Once separated, the alginate and the crude extract were characterised and the biological activities and cytotoxicity of the extracts was studied, the latter in intestinal epithelial cells. Those alginates obtained at 90 °C exhibited the highest extraction yields and viscoelastic features of the corresponding hydrogels. The obtained results show that the extracts obtained by non-isothermal extraction were suitable to formulate nanoparticles, which showed the smallest size (≈ 250-350 nm) when the higher content of fucoidan extract was present. Given the evidenced properties, the extracts may find an application in the formulation of nanoparticulate carriers for drug delivery.

Recovery of bioactive and gelling extracts from edible brown seaweed Laminaria ochroleuca by non-isothermal autohydrolysis.

The non-isothermal autohydrolysis temperature impact of edible brown seaweed Laminaria ochroleuca was studied to recover high valuable compounds. Extraction yield was determined, above 80% was obtained at 220 °C. The maximal fucose content (17% d.b.) was attained at 180 °C, whereas the maximal sulphate was achieved at 160 °C, and phenolic and protein content at 220 °C. The maximum sulphated fucoidan content (41.38 g fucoidan/100 g extract) was obtained at 160 °C, whereas the maximum fucose oligosaccharides was obtained at 180 °C. The antioxidant capacity was equivalent to 32 mg Trolox/g dry extract produced at 220 °C. The milder processing condition was selected to study the potentiality of the precipitated alginate in terms of viscoelastic properties determined by rheology. Alginate extraction (14.94 g/100 g extract) was determined at 160 °C. The crude fucoidan fractions were tested at 25-500 µg/mL, showed up to 50% cell growth inhibition in four selected tumoral cell lines.

Application of hull, bur and leaf chestnut extracts on the shelf-life of beef patties stored under MAP: Evaluation of their impact on physicochemical properties, lipid oxidation, antioxidant, and antimicrobial potential.

The impact of chestnut extracts (Castanea sativa) from leaf, bur and hull at different concentrations on the shelf-life of beef patties during 18 days of refrigerated storage at (2 ±â€¯1 °C) was studied and compared to control and synthetic antioxidant (BHT) samples. Total phenolics and in vitro antioxidant capacity of extracts were evaluated by using DPPH, FRAP, reducing power and oil accelerated oxidation test (peroxide value, conjugated dienes, p-anisidine and fatty acid profile). The microbial spoilage, colour parameters, lipid oxidation and sensorial properties were used to assess antioxidant activity in beef patties. The highest total phenolic content was found in bur extracts (43.68 ±â€¯2.05 g/100 g lyophilized extract). In addition, bur extracts showed the strongest antioxidant activity in all in vitro assays. None of the evaluated extracts showed antimicrobial activity. The addition of hull extracts at 500 and 1000 ppm resulted in the highest (P < .05) metmyoglobin reduction in the surface of beef patties compared to control and the others batches after 15 days of storage. However, leaf extract at 1000 ppm was the most effective in inhibiting lipid oxidation. Overall, for all extracts evaluated, the increase in the concentration of chestnuts extracts improved the desired effect, hence our findings suggest the possibility of using chestnuts extracts (preferable a mixture from the different parts of the chestnut byproducts) rather than synthetic antioxidants. Finally, sensorial analysis did not show any detrimental effect from a sensory point of view, after the addition of chestnuts extracts, thus indicating a potential to develop chestnut extracts as food ingredients.

Recent developments on the extraction and application of ursolic acid. A review.

Ursolic acid (UA) is a pentacyclic triterpenoid widely found in herbs, leaves, flowers and fruits; update information on the major natural sources or agro-industrial wastes is presented. Traditional (maceration, Soxhlet and heat reflux) and modern (microwave-, ultrasound-, accelerated solvent- and supercritical fluid) extraction and purification technologies of UA, as well as some patented process, are summarized. The great interest in this bioactive compound is related to the beneficial effects in human health due to antioxidant, antimicrobial, anti-inflammatory, hepatoprotective, immunomodulatory, anti-tumor, chemopreventive, cardioprotective, antihyperlipidemic and hypoglycemic activities, and others. UA may augment the resistance of the skin barrier to irritants, prevent dry skin and could be suitable to develop antiaging products. The development of nanocrystals and nanoparticle-based drugs could reduce the side effects of high doses of UA in organisms, and increase its limited solubility and poor bioavailability of UA which limit the potential of this bioactive and the further applications. Commercial patented applications in relation to cosmetical and pharmaceutical uses of UA and its derivatives are surveyed.

Characterization, refining and antioxidant activity of saccharides derived from hemicelluloses of wood and rice husks.

Samples of rice husks, Eucalyptus globulus wood and Pinus pinaster wood (containing arabinoxylan, acetylated glucuronoxylan and acetylated glucomannan as major hemicellulose components, respectively) were subjected to autohydrolysis. The resulting liquid phases, containing mainly hemicellulose-derived saccharides, were refined by physicochemical methods to reduce their contents of monosaccharides and non-saccharide compounds. Raw autohydrolysis liquors and refined concentrates coming from aqueous treatments were assayed for antioxidant activity using the following assays: reducing power (FRAP), DPPH and ABTS radical scavenging activity and protection of ß-carotene-linoleic emulsions from oxidation. The reducing power and radical scavenging capacity of the non refined fractions were comparable to the ones determined for the reference compound butylhydroxytoluene. Hemicellulose concentrated from the different feedstocks and refining protocols showed a dose dependent antioxidant activity in the range of concentrations evaluated. The in vitro antioxidant activity of concentrates correlated with their phenolic content.

In vitro antioxidant properties of crude extracts and compounds from brown algae.

Research on the bioactives from seaweeds has increased in recent years. Antioxidant activity is one of the most studied, due to the interest of these compounds both as preservatives and protectors against oxidation in food and cosmetics and also due to their health implications, mainly in relation to their potential as functional ingredients. Brown algae present higher antioxidant potential in comparison with red and green families and contain compounds not found in terrestrial sources. In vitro antioxidant chemical methods, used as a first approach to evaluate potential agents to protect from lipid oxidation in foods, confirmed that the brown algae crude extracts, fractions and pure components are comparatively similar or superior to synthetic antioxidants. Particular emphasis on the fucoidan and phlorotannin polymeric fractions is given, considering variations associated with the species, collection area, season, and extraction and purification technologies.