Search Results (2,154)

Seaweeds are increasingly valued in the food industry for their bioactive compounds, mainly hydrocolloids like carrageenan. This study investigates E. perplexum, a red seaweed, as a unique and sustainable source of carrageenan with promising functional properties. Using response surface methodology (RSM), the extraction process was optimized through alkaline extraction, identifying optimal conditions of 85 °C for 3 h with 2.58 M KOH, which yielded 77.10% carrageenan. The extracted carrageenan exhibited strong emulsifying activity (71.53 ± 2.41) and color properties comparable to commercial carrageenan, highlighting its viability for food applications. Chemical evaluation revealed a higher sulfate content (8.45 ± 0.16) and slightly reduced carbohydrate levels, which may influence its gelling and stabilizing abilities. Structural examination through ATR-FTIR spectroscopy corroborates the presence of key functional groups, including sulfate esters and galactose derivatives, inferring molecular integrity. These results emphasize the importance of RSM in optimizing extraction and underscore the ability of E. perplexum as a promising source of the derived carrageenan, which is a high-performance additive in food systems. Further research on purification, functional enhancement, and safety assessment is recommended to facilitate its integration into commercial food systems. Full article

This paper presents a novel submersible seaweed cultivation infrastructure designed to enhance seaweed growth through deep cycling. The system consists of a square grid of ropes for growing seaweed, supported by buoys, mooring lines, and innovative SubTractors—movable buoys that enable controlled submersion. The grid ropes are stabilized by four SubTractors, an array of small buoys, intermediate sinker weights and mooring lines anchored to the seabed. The SubTractors facilitate dynamic positioning, allowing the seaweed rope grid to be submerged below the thermocline—at depths of 100 m or more—where nutrient-rich deep water accelerates seaweed growth in offshore sites with low surface nutrient levels. Small buoys attached to the grid provide buoyancy, keeping the seaweed rope grid planar and near the surface to optimize photosynthesis when not submerged. This paper first describes the seaweed cultivation infrastructure, then develops a hydroelastic model of the proposed cultivation system, followed by a hydroelastic analysis under varying wave and current conditions. The results provide insights into the system’s dynamic behaviour, informing engineering design and structural optimization. Full article

Sulfated polysaccharides (SPs) are abundant in seaweed and have several industrial and biomedical applications, but their renal effects remain unclear. This study evaluated the effects of total sulfated polysaccharides (TSPs) from Gracilaria cornea using an isolated rat kidney perfusion model. TSP at 3 µg/mL increased perfusion pressure and renal vascular resistance at 90–120 min, while 4.5 µg/mL induced earlier and more pronounced changes (from 60 min). Urinary flow decreased at 1 µg/mL (90 min) but increased at 4.5 µg/mL (90–120 min). Sodium transport was reduced at all concentrations, whereas potassium and chloride transport remained unchanged. Histological analysis revealed protein deposits in tubules and urinary space, indicating tubular injury. In vitro, TSP reduced MDCK cell viability in a concentration-dependent manner and induced apoptosis, with some cells progressing to secondary necrosis. In conclusion, TSP altered renal physiology and morphology and triggered apoptotic pathways in renal cells, highlighting the need for further mechanistic and translational studies. Full article

Fucoidan B (FucB) is a sulfated polysaccharide with recognized biological activity. In this study, FucB was chemically modified through redox conjugation with gallic acid (GA) to obtain FucB-GA, aiming to enhance its antioxidant properties. Structural characterization using FTIR, NMR, and electrophoresis confirmed the successful covalent binding of GA to FucB without major structural degradation. The conjugation increased the phenolic content and reduced crystallinity, as shown by XRD and SEM, indicating greater amorphous character, which can favor biological applications. Thermogravimetric analysis demonstrated enhanced thermal stability in FucB-GA. Antioxidant activity was evaluated through various in vitro assays. FucB-GA showed superoxide radical scavenging activity of 91.96%, copper chelating capacity of 43.2%, antioxidant capacity of 37 mg AEE/g, and reducing power of 94.22%, significantly higher results than FucB, while no sample chelated iron. Under the conditions analyzed, gallic acid alone showed minimal or no activity in most assays. These results suggest that conjugation with GA increases the antioxidant potential of FucB, while also improving the activity and bioavailability of GA, likely due to the increase in electron-donating and metal-binding groups. Overall, the study supports the development of FucB-GA as a promising antioxidant compound for pharmaceutical or nutraceutical applications. Full article

Various therapeutic approaches have been explored to speed up wound healing, with angiogenesis being a crucial factor in this process and skin repair. This study shows that a polysaccharide extracted from the red alga Osmundea pinnatifida (PSOP) can promote angiogenesis and accelerate healing. The structural properties of PSOP were investigated using various techniques, including scanning electron microscopy, X-ray diffraction, Fourier–transform infrared spectroscopy, ultraviolet–-visible spectroscopy, and high-performance liquid chromatography coupled with a refractive index detector. Additionally, the in vitro antioxidant activity of PSOP was evaluated using the reducing power assay, total antioxidant capacity measurement, and DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging tests. The PSOP extract exhibited significant pro-angiogenic effects in the avian chorioallantoic membrane model. Furthermore, the efficacy of PSOP-based hydrogels for wound healing was assessed in vivo using an excision wound model in Wistar rats. The results indicated accelerated wound healing, increased collagen deposition, and enhanced tissue regeneration. Computational studies suggest that the observed wound healing and pro-angiogenic effects may be attributed to the affinity of the PSOP units for cyclooxygenase-2 and vascular endothelial growth factor. These findings support the potential use of PSOP as a bioactive agent in wound care. Full article

This study investigates the anti-obesity and antidiabetic potential of P. palmata extracts produced through sequential enzymatic and alkaline treatments. Among the treatment groups, the extract treated solely with Alcalase^® (Alc) demonstrated the highest protein content (10.11 ± 0.15%) and degree of hydrolysis (30.36 ± 0.77%), significantly outperforming other treatments (p < 0.05). The Alc extract also exhibited superior inhibitory activity against porcine pancreatic lipase and α-amylase, achieving the lowest IC₅₀ for lipase (2.29 ± 0.87 mg.mL⁻¹) and showing significant enzyme inhibition across all tested concentrations (p < 0.05). Ultrafiltration of the Alc extract revealed that peptide fractions < 1 kDa and 1–3 kDa were most effective in enzyme inhibition, with IC₅₀ values of 3.25–3.55 mg.mL⁻¹ for both lipase and α-amylase. Peptides were identified via LC-MS/MS analysis and database searching using SequestHT, resulting in 536 sequences, of which bioinformatic screening yielded 51 non-toxic, non-allergenic candidates (PeptideRanker score > 0.6); four of these contained known inhibitory motifs for lipase and α-amylase. Molecular docking confirmed strong binding affinities between these peptides and their respective enzymes, supporting their potential as natural enzyme inhibitors. These findings indicate the functional food potential of Alcalase^®-derived P. palmata peptides for managing obesity and type 2 diabetes. Full article

Seaweeds are promising third-generation biomass for biobased chemicals, yet their use for lactic acid (LA) production remains underexplored. We evaluated LA production from the dilute-acid hydrolysate of the aquacultured green alga Capsosiphon fulvescens (C.Agardh) Setchell & N.L. Gardner. The dried biomass contained 53.4% carbohydrate (dry-weight basis). HPLC showed a monosaccharide profile enriched in L-rhamnose and D-xylose, with lower levels of D-mannose, D-glucose, D-glucuronolactone, and D-glucuronic acid. Batch fermentations with three Lactobacillus strains revealed clear strain-dependent kinetics and carbon partitioning. Maximum LA titers/yields (time at maximum) were 2.0 g L⁻¹/0.49 g g⁻¹ at 9 h for L. rhamnosus, 2.3 g L⁻¹/0.30 g g⁻¹ at 36 h for L. casei, and 2.8 g L⁻¹/0.23 g g⁻¹ at 48 h for L. brevis; L. rhamnosus achieved the highest yield on sugars consumed, whereas L. brevis reached the highest titer by utilizing a broader sugar spectrum, notably xylose; L. casei showed intermediate performance with limited xylose use. Co-products included acetic and succinic acids (major) and trace 1,2-propanediol and acetaldehyde, consistent with flux through Embden–Meyerhof–Parnas versus phosphoketolase pathways. These results demonstrate that C. fulvescens hydrolysate is a viable marine feedstock for LA production and highlight practical levers—expanding pentose/uronic-acid catabolism in high-yield strains and tuning pretreatment severity—to further improve both yield and titer. Full article

In recent years, insects have emerged as a nutritious and eco-sustainable alternative food source, with the house cricket (Acheta domesticus, AD) recently authorized by the European Commission as a novel food. However, the presence of harmful substances in insects poses potential health risks. This study investigated the content of potentially toxic elements (PTEs) such as cadmium (Cd), arsenic (As), lead (Pb), mercury (Hg), nickel (Ni), chromium (Cr), and aluminium (Al) in Acheta domesticus fed diets enriched with graded levels of the red seaweed Palmaria palmata or the brown seaweed Ascophyllum nodosum in two feeding trials. Chemical analyses were carried out by graphite furnace atomic absorption spectrophotometry for all elements except Hg, which was analyzed by thermal decomposition amalgamation atomic absorption spectrometry. The results showed that PTE content in the diets was below the legal limits for feed. The PTEs in AD ranged (mg kg⁻¹ dry matter) as follows: Cd (0.069 ± 0.005–0.127 ± 0.002), As (0.08 ± 0.01–0.36 ± 0.03), Pb (0.05 ± 0.01–0.12 ± 0.01), Hg (0.0065 ± 0.0002–0.0141 ± 0.0010), Ni (0.64 ± 0.06–1.20 ± 0.10), Cr (0.16 ± 0.02–0.58 ± 0.01), and Al (17 ± 2–61 ± 1). AD bioaccumulated As and Hg; however, the PTE levels remained below European Union food safety limits. The absence of non-carcinogenic risk for consumers suggests that AD fed seaweed-enriched diets are a safe, healthy, and low-chemical risk food for humans. Full article

Colaconema daviesii has been described as an epi-endophyte of red algae. However, it has also been observed in vitro to colonize thalli of Macrocystis pyrifera, a giant kelp classified as a foundational organism of coastal marine ecosystems. This study aimed to determine, through co-cultivations, how C. daviesii affects the early stages of M. pyrifera, specifically gametophyte and sporophyte development. Determined were growth, oogonia formation, and gametophyte fertility, as well as sporophyte growth rate and survival. The results showed that the presence of C. daviesii negatively altered oogonia production and gametophyte fertility. Moreover, the survival of young sporophytes in co-cultures decreased. These findings demonstrate that the early developmental stages of M. pyrifera could be susceptible to infestation by a filamentous red alga, with negative consequences on fitness. Full article

Climate change significantly impacts fruit production and yield, affecting its commercial value. Foliar fertilization emerges as a fast and targeted strategy to address crop nutrient deficiencies and enhance fruit quality. Sweet cherry is among the most highly valued and widely appreciated fruit crops globally. This study was conducted over two consecutive years on the sweet cherry cv. Sweetheart. Calcium (300 g hL⁻¹ and 150 g hL⁻¹) and a seaweed-based biostimulant (150 mL hL⁻¹ and 75 mL hL⁻¹), as well as a combination of both nutrients (300 g hL⁻¹ calcium and 150 mL hL⁻¹ seaweed), in addition to a control treatment (water), were applied at the foliar level to improve sweet cherry quality. To assess cherry quality, including biometric, chromatic, texture, and biochemical parameters, as well as the sensory analysis, fruits from each treatment were harvested at the commercial maturity stage. Calcium treatments improved fruit size, total soluble solids, and firmness, while also delaying fruit ripening by increasing titratable acidity. The seaweed-based biostimulant enhanced fruit size, promoted color development, and accelerated ripening. Together, these findings highlight the crucial role of calcium in improving sweet cherry quality and underscore seaweed-based biostimulants as a promising and sustainable strategy for enhancing fruit quality. Although cherry quality is highly affected by environmental conditions, this study demonstrated that calcium fertilization, either alone or in combination with seaweed, enhances sweet cherry quality attributes, making it a suitable strategy for application in commercial orchards and for the global improvement of sweet cherry production. Full article

The global increase in life expectancy underscores the need to promote healthy aging, particularly by addressing age-related leaky gut syndrome, which contributes to systemic inflammation and chronic disease. This study focused on the sustainable production and functional development of Ulva meridionalis, a fast-growing seaweed, to improve gut health and mitigate the effects of aging. Using land-based aquaculture, a scalable cultivation system for U. meridionalis was established, and its polysaccharide, ulvan, was extracted. Ion exchange treatment enhanced the functionality of ulvan to produce ulvan-Na, which contains high levels of Na⁺ and conveys superior anti-aging properties. Ulvan-Na restored intestinal barrier integrity in aged mice by reducing serum LPS levels and increasing claudin-1 expression. Ulvan-Na modulated the gut microbiota, increasing beneficial bacteria such as Clostridiales vadin BB60 and suppressing inflammatory bacteria such as Turicibacter. The mechanism was clarified whereby ulvan-Na activates β-catenin to enhance claudin-1 expression. These findings highlight ulvan-Na as a bioactive compound that ameliorates age-related intestinal dysfunction while demonstrating the feasibility of sustainable U. meridionalis production for functional food innovation and environmental conservation. Full article

Currently, biostimulants in the horticultural sector are a tool that is being used to improve the yield and quality of vegetables under optimal and stressful growth conditions. In the present study, we evaluate the effects of foliar application of a hydroethanolic extract of Sargassum spp., a commercial extract based on Ascophyllum nodosum, and a control with distilled water on growth and biomass, stomatal conductance, photosynthetic pigments, enzymatic and non-enzymatic antioxidants, protein content, and the expression of defense genes in tomato plants (Solanum lycopersicum L.) without stress and with high-temperature stress (45 °C). The results showed that Sargassum spp. extract only increased the height of tomato plants under stress-free conditions (2.71%) in the last evaluation. The aboveground and total dry biomass of the plants were increased by Sargassum spp. extract under stress-free conditions by 9.56 and 8.58%, respectively. Under stress conditions, aboveground dry biomass was increased by 6.66% by Sargassum spp. extract. Stomatal conductance, photosynthetic pigments, protein content, enzymatic and non-enzymatic antioxidants, and defense gene expression of tomato plants were positively modified with the use of Sargassum spp. and A. nodosum extract under high-temperature stress conditions. Under stress-free conditions, the described variables were positively modified except for gene expression, where some genes were expressed and others were repressed. The results indicate that extracts of Sargassum spp. and A. nodosum are effective in mitigating high-temperature stress, making their use a promising alternative for inducing resistance in plants to the daily adversities of climate change. Full article

This review focuses on five native Australian brown algae species—Cystophora torulosa, Durvillaea potatorum, Ecklonia radiata, Hormosira banksii, and Phyllospora comosa—evaluating their environmental adaptability, biochemical composition, bioactive compounds, and potential for commercial development. Species-specific differences in temperature and light tolerance influence their habitat distribution. Nutritional assessments reveal that these algae are rich in proteins, polysaccharides, polyunsaturated fatty acids, and essential trace elements. Bioactive compounds, including polyphenols and fucoidans, exhibit antioxidant, anti-inflammatory, and anti-diabetic properties. D. potatorum extracts have considerable economic value in agriculture by enhancing crop yield, improving nutritional value, and promoting root development. C. torulosa is predominantly found in cooler marine environments and is comparatively more thermally sensitive. In contrast, H. banksii has a higher heat tolerance of up to 40 °C and thrives in warmer environments. E. radiata is widely distributed, highly tolerant of environmental stresses, and exhibits notable disease-resistant activities. P. comosa, due to its high polysaccharide content, demonstrates strong potential for industrial applications. Consumer studies indicate growing acceptance of seaweed-based products in Australia, although knowledge gaps remain. This study highlights the need for continued research, optimized processing methods, and targeted education to support the sustainable development and utilization of Australia’s native brown algae resources. Full article

Poor solubility and bioavailability have limited the application of fucoxanthin and functional food processing. In order to encapsulate fucoxanthin in delivery systems, cellulose nanofibril-stabilized emulsion gels (CNFs) derived from industrial brown seaweed residue were developed to enhance fucoxanthin delivery. Cellulose nanofibrils (CNFs) were isolated using high-pressure homogenization at 105 MPa through 5, 10, and 15 cycles (denoted as C5, C10, and C15) and yielding reduced crystallinity down to 52.91 ± 2.13% (C15). The minimum particle size of the present CNFs is approximately 37 nm (C15). Moreover, single-factor and orthogonal experiments optimized the stability of the present emulsion. A 17.5 mg/mL CNFs 50% oil phase with coconut oil, 0.5 mg/mL fucoxanthin, and homogenization for 60 s were identified to be the optimal conditions for such emulsion gel. The present emulsions demonstrated a high storage stability at 4 °C versus 25 °C, which maintained minimal phase separation over 8 days. The release kinetics showed significant dependencies with fucoxanthin release increasing to 9.22 ± 0.62% at pH 8.0, 9.52 ± 0.58% under 1000 mM NaCl, and 8.25 ± 0.62% at 100 °C. In addition, the CNFs effectively preserved the antioxidant activity of the fucoxanthin under different pH values, salinities, and temperatures. The results establish seaweed-derived CNFs as effective stabilizers for fucoxanthin encapsulation, enhancing stability while preserving functionality against food-processing stresses. To our knowledge, no prior research has been reported on a fucoxanthin delivery system utilizing an emulsion gel stabilized by cellulose nanofibrils (CNFs). Such emulsions might provide a sustainable strategy for valorizing seaweed waste and advance functional food applications of marine bioactives. Full article

Inflammatory muscle loss results from excessive inflammatory responses, causing muscle damage and weakness. In the current investigation, we evaluated the protective effects of diphlorethohydroxycarmalol (DPHC) against tumor necrosis factor-alpha (TNF-α)-induced skeletal muscle inflammation and muscle loss and elucidated the underlying mechanisms. Furthermore, the effect of DPHC on swimming performance was confirmed under TNF-α-induced inflammatory muscle loss-conditioned zebrafish by assessing the swimming number, distance moved, time spent swimming, frequency of swimming zebrafishes in an upstream swim track (Zone A). In vivo behavioral endurance test results indicated that TNF-α treatment significantly decreased the number of swimming zebrafish and swimming distance in Zone A compared with the Control. Meanwhile, the DPHC treatment significantly increased the number of swimming zebrafish and swimming distance in Zone A compared to TNF-α-induced zebrafish. These findings indicate that DPHC treatment effectively improved the swimming performance of TNF-α-induced zebrafish. In an additional study, TNF-α significantly induced inflammatory muscle loss by upregulating nuclear factor kappa light chain enhancer of activated B cells (NF-κB) mitogen activated protein kinase (MAPK) associated proteins and MuRF-1 in the skeletal muscle tissues of TNF-α-induced zebrafish. However, DPHC administration significantly counteracted TNF-α-induced inflammation and muscle loss by downregulating NF-Κb and MAPK-associated proteins, as well as the muscle degradation-related proteins MuRF-1 and MAFbx, in the skeletal muscle tissues of TNF-α-induced zebrafish. In summary, our research findings demonstrated that DPHC from Ishige okamurae could be used for the development of nutraceuticals or functional foods targeting inflammatory muscle loss. Full article