Search Results (355)

This study investigated the effects of alkaline pretreatment and drying methods on the physicochemical properties of Gelidium amansii and the quality of the resulting agar jelly. Seaweeds with or without alkaline pretreatment were subjected to either sun-drying or shortwave infrared (SWIR) lamp-drying for three or seven cycles to evaluate whether SWIR drying could replace conventional sun-drying by reducing drying time and whether alkaline pretreatment could enhance gel hardness. The results showed that both drying methods effectively reduced moisture content, while the alkaline pretreatment significantly increased the ash content, likely due to the removal of water-soluble components. Marked color improvement was observed after seven cycles of sun-drying or following alkaline pretreatment, with the appearance changing from purplish red to bright golden yellow, which is closer to traditional quality expectations. Although SWIR lamp-drying was more energy-efficient, it resulted in limited color improvement. Volatile compound analysis revealed that deviations from the fresh control increased with the number of sun-drying cycles, whereas alkaline pretreatment and infrared-drying induced more pronounced changes in volatile profiles. Among all of the treatments, Gelidium subjected to seven sun-drying cycles produced jellies with the most favorable texture, indicating enhanced agar gel formation through repeated washing and drying. In contrast, the combination of alkaline pretreatment and infrared-drying restricted agar extraction, likely due to tissue hardening and insufficient light intensity, resulting in weak or negligible gel formation. Overall, both the drying method and alkaline pretreatment significantly influenced the Gelidium quality and agar gel properties; despite being labor-intensive, traditional washing and sun-drying processes remain critical for achieving desirable product quality. Full article

Brown seaweeds are marine bioresources rich in bioactive compounds such as carbohydrates, proteins, pigments, fatty acids, polyphenols, vitamins, and minerals. Among these substances, brown algae-derived polysaccharides (alginate, fucoidan, and laminarin) have promising industrial prospects owing to their distinctive structural features and diverse biological activities. Consequently, processing technologies have advanced substantially to address industrial requirements for biopolymer quality, cost-effectiveness, and sustainability. Over the years, significant progress has been made in developing various advanced methods for the sake of extracting, purifying, and structurally characterizing polysaccharides. Aside from that, numerous studies reported their broad spectrum of biological activities, such as antioxidant, anti-inflammatory, anticoagulant, and antimicrobial properties. Furthermore, these substances have various industrial, pharmaceutical, bioenergy, food, and other biotechnology applications. The present review systematically outlines the brown algae-derived polysaccharides treatment process, covering the entire value chain from seaweed harvesting to advanced extraction methods, while highlighting their biological activities and industrial potential as well. Full article

Repairing bone defects with implants is an important topic in the field of regenerative medicine, but bacterial infection presents a significant barrier in clinical practice. Therefore, bone implants with antibacterial functionality are currently in high demand. Fresh seaweed-derived exosomes (EXOs) exhibited promising antibacterial activity against bacteria, indicating their potential as natural antimicrobial agents. Moreover, equipping the exosomal lipid bilayer with bacteria-targeting aptamers (Apt), termed EXOs-Apt, enabled precise bacterial killing, thereby promoting more effective antibacterial functions. In our design, porous polyetheretherketone (PEEK) scaffolds were 3D-printed using the melt deposition manufacturing process. Subsequently, the scaffold surfaces were modified via dopamine self-polymerization, resulting in the formation of a polydopamine (PDA) coating. Then, EXOs-Apt was applied to functionalize PEEK scaffolds with antibacterial activity. Given that EXOs display bactericidal effects while Apt facilitates bacterial capture, we engineered a surface coating platform that incorporates both components to produce a multifunctional scaffold with synergistic antibacterial activity. The results showed that modifying EXOs-Apt on PEEK scaffolds significantly improved their antibacterial performance against Escherichia coli and Staphylococcus aureus. To our knowledge, this is the first study to use EXOs-Apt as antibacterial coatings modified on PEEK scaffolds. This study provides new strategies and ideas for the development of antibacterial PEEK orthopedic implants with promising clinical value for infection-resistant repair of bone defects. Full article

Seaweeds are emerging renewable biomass resources rich in valuable phytochemicals; however, effective stabilization strategies are required to enable their incorporation into sustainable food and bioprocessing applications. This study investigated the effects of convective drying (40–80 °C) and freeze-drying on the chemical composition and functional properties of the underexplored red seaweed Sarcodiotheca gaudichaudii. The drying method significantly modulated nutrient retention, pigment stability, and bioactivity. Freeze-drying and high-temperature convective drying (≥70 °C) resulted in higher protein and saturated fatty acid contents but led to substantial losses of pigments and antioxidant capacity. In contrast, moderate convective drying (40–60 °C) favored the retention of minerals, polyunsaturated fatty acids, essential amino acids, and pigments, while enhancing total phenolic and flavonoid contents and improving antioxidant performance (DPPH and ORAC). All extracts exhibited dose-dependent α-glucosidase inhibition (25–58%) within a concentration range of 0.10–40.0 mg/mL, with freeze-dried samples showing the strongest inhibitory effect. Similarly, cytotoxicity assays conducted on A549 and AGS cancer cell lines at concentrations of 1.25–40.0 mg/mL revealed that freeze-dried extracts consistently displayed the lowest IC₅₀ values. Overall, convective drying better preserved nutritional quality, whereas freeze-drying maintained higher biological functionality, revealing a process-dependent trade-off relevant to industrial biomass stabilization and functional ingredient development. Full article

This study explored the production of a fermented beverage using Huiro negro (Lessonia spicata), a brown seaweed, as a substrate. The cellulosic saccharification (CS) process was optimized via response surface methodology, identifying that the best conditions were 60 U/g of enzyme at 60 °C for 1.9 h, yielding 2.5 g/100 g of reducing sugars. The resulting hydrolysate was fermented with Lactobacillus spp. for 48 h at 30 °C and compared with a non-saccharified control. The beverage’s proximate composition, total phenolic content (TPC), flavonoid content (TFC), antioxidant capacity (AC), and Lactobacillus spp. viability over 16 days of storage at 4 °C were assessed. CS-treated samples showed a progressive increase in TPC, reaching 126.59 ± 5.58 mg GA/L, which correlated with higher AC. However, no significant differences (p > 0.05) were observed in TPC and AC between saccharified and non-saccharified beverages. Notably, the CS-treated beverage achieved significantly higher (p < 0.05) Lactobacillus spp. counts (10⁹ CFU/mL) compared to the control (10⁷ CFU/mL), maintaining viability throughout storage. While further research is needed to confirm bioavailability and gut health effects, these findings shows that enzymatic saccharification substantially improves fermentation performance and functional properties in Lessonia spicata-based beverages. Full article

Modern fruit crop production increasingly seeks sustainable strategies to enhance growth, yield, and fruit quality while minimizing environmental impacts. Plant biostimulants—naturally derived substances or beneficial microorganisms, such as seaweed and plant extracts, Plant-Growth-Promoting Rhizobacteria (PGPR), humic substances, protein hydrolysates, and Si—emerge as promising tools to achieve these goals by stimulating key physiological and biochemical processes. They can improve nutrient uptake and efficiency, modulate hormonal and metabolic pathways, and enhance the activity of enzymatic and non-enzymatic antioxidants, leading to improved plant vitality and fruit quality. Biostimulants also influence rhizosphere microbial communities and soil health, promoting nutrient cycling, beneficial microbial diversity, and soil structure. This review evaluates the application of biostimulants in fruit crops and their effects on growth, physiology, productivity, fruit quality, both chemical and nutritional composition and physical parameters. Challenges related to variability in efficacy, formulation standardization, and crop-specific responses are discussed, alongside future perspectives on integrating biostimulants into sustainable orchard management. Overall, biostimulants represent multifunctional tools that support both productivity and ecological sustainability in modern fruit production systems. Full article

This study introduced a new small-scale semi-mechanized planting method for Kappaphycus alvarezii (Doty) and compared its efficiency to traditional methods. A semi-mechanized sewing (S-MS) device was designed to speed up the planting process using affordable materials. To validate the S-MS model, three different cultivation systems (S-MS method, tie-tie, and tube-net systems) using two color morphotypes of K. alvarezii were implemented, each in triplicate. The experiment spanned 40 days. Water quality and technical indicators were monitored, and data on material consumption and productivity were analyzed. The exclusive S-MS mechanism was successfully completed. The S-MS significantly reduced rope usage by 4.3 times per each propagule sewn to the main cable and planting time (S-MS = 1 min 12 s per meter) compared to the traditional method (tie-tie = 1 min 48 s per meter). Final biomass varied among treatments (p < 0.05), with the S-MS method showing a higher final biomass (15.26 ± 0.88 kg) with olive green K. alvarezii. The average daily growth rates (6.38%) were higher for the S-MS method with olive green K. alvarezii. The S-MS technique offers cost and time savings for seaweed farmers, making it a viable alternative to traditional methods, showed comparable productivity to tie-tie but superior efficiency and resource economy. Full article

Cognitive decline associated with healthy ageing and pathological conditions is driven by multifactorial processes, including oxidative stress, mitochondrial dysfunction and chronic neuroinflammation. Alzheimer’s Disease (AD), a progressive neurodegenerative disorder affecting cognition and behaviour, is the leading cause of dementia worldwide. Current pharmacological interventions provide modest and transient benefits, targeting limited molecular pathways with safety and cost concerns, underscoring the need for safe, accessible and multi-targeted strategies. This review explores new avenues of therapy with a focus on bioactive compounds derived from brown, red and green seaweeds and their potential to modulate key mechanisms underlying AD. Preclinical and emerging clinical studies demonstrate that phlorotannins, fucoidans, fucoxanthin, lutein, zeaxanthin, ulvan, and astaxanthin exert antioxidant, anti-inflammatory, cholinergic-modulating and neuroprotective effects. Supplementation with seaweed-derived bioactive compounds has been shown to exert molecular and cellular effects that lead to reduced amyloid burden, preservation of synaptic integrity, and enhanced cognitive performance. Collectively, seaweed-derived compounds represent promising candidates for multi-target therapeutic strategies in cognitive decline prevention in the context of AD and healthy brain ageing. Full article

This study deals with the incorporation of biostimulants of natural origin in a biodegradable polymeric matrix, with the aim of developing mulch films that, when degraded in the soil, release bioactive compounds that improve soil quality and favor the agronomic growth of crops. Three types of commercial biostimulants were used: one based on seaweed extract, one on lignosulfonates, and one on plant-derived essential amino acids. To ensure the thermal stability of the biostimulant compounds during processing, thermogravimetric analyses (TGAs) were carried out, and a methodology based on the adsorption of the biostimulants onto porous substrates was developed, enabling their effective incorporation into the polymeric matrix. The formulations obtained have been processed by blown film extrusion at a pilot scale. In addition, the presence of film residues in soil was analyzed by pyrolysis–gas chromatography–mass spectrometry (Py-GC/MS). The results indicate that the proposed methodology supports the integrity of the biostimulants in the films obtained. After the incubation period studied, complete degradation of the biopolymer and the absence of film residues in the soil were confirmed. Furthermore, it was confirmed that this final product had no adverse effects on organisms that were representative of the two end-of-life scenarios, with the exception of the film functionalized with the commercial biostimulant based on seaweed extract, which showed a negative effect on terrestrial higher plants. Full article

Fixation is a necessary step in bamboo leaf powder processing and plays a decisive role in determining its color, aroma, and taste. It is irreplaceable for maintaining quality, stability, and forming unique sensory characteristics. In this study, optimal conditions for steamed bamboo leaf powder (SBL), baked bamboo leaf powder (BBL), and blanched bamboo leaf powder (BCBL) were determined by measuring chlorophyll content, color parameters, and enzyme inactivation. In addition, volatile organic compounds (VOCs) in bamboo leaf powder processed with different fixation methods were analyzed using gas chromatography–mass spectrometry (GC-MS), gas chromatography–olfactometry (GC-O), and relative odor activity value (ROAV). Steaming for 120 s, baking for 60 s, and blanching for 30 s effectively preserved color, with a* values of −1.37, −1.44, and −1.62, all superior to untreated bamboo leaf powder (UBL). Among them, BCBL showed the best color stability, with the lowest color difference (ΔE = 0.66) compared with fresh bamboo leaves (FBLs). Results showed that BBL retained the highest VOC abundance (15.67% of FBLs), followed by SBL (5.73%) and BCBL (5.48%). Hexanal, nonanal, linalool, and α-ionone were identified as key aroma contributors, forming green, fresh, and floral notes. Sensory differences were evident: SBL exhibited strong seaweed-like and roasted notes, BCBL showed partial loss of characteristic aromas, while BBL preserved grass, fruity, and woody attributes. These findings highlight the significant influence of fixation methods on aroma-active compounds and color stability, providing a theoretical basis for producing bamboo leaf powder with superior sensory quality. Full article

This study analyzed the economic feasibility of utilizing Undaria pinnatifida sporophylls (UPSs), a major by-product of seaweed aquaculture, as feed for Hanwoo cattle. It employed a partial equilibrium framework to quantify processing costs, avoided disposal costs, substitution savings from reduced grain imports, and monetized methane abatement benefits, calibrated with national statistics on Hanwoo production and feed use for 2022–2024. The analysis revealed that, in the absence of environmental valuation, additional collection, transport, and drying costs (KRW 25,714–102,857 per head at 0.25–1.0% inclusion) outweighed savings from disposal avoidance and import substitution. When methane abatement was priced under Korea’s Emissions Trading Scheme, however, net benefits emerged, ranging from KRW 22,757 to 40,859 per head, with welfare gains of KRW 19,108 million at 1.0%. Sensitivity analysis confirmed a strong dependence on carbon prices: benefits were substantial at KRW 40,000 per ton of CO₂, remained positive yet relatively limited at KRW 20,000, and shifted into negative territory at KRW 10,000. These findings demonstrate that UPS feed utilization can advance climate mitigation and feed security, provided it is supported by effective carbon pricing and producer-oriented policies. Full article

Phlorotannin–alginate extracts from brown seaweeds offer promising natural solutions for food preservation. This study investigated the extraction, characterization, and application of phlorotannins and alginate from two brown seaweed species, Sargassum cristaefolium and Nizimuddinia zanardinii, for inhibiting melanosis and preserving quality in Pacific white shrimp during ice storage. Preliminary screening identified N. zanardinii methanol extract as superior, yielding the highest phlorotannin content (19.14 ± 0.65 mg Phloroglucinol/g) with potent antioxidant (98.95 ± 0.74% DPPH inhibition) and copper-chelating (73.44 ± 1.64%) activities. Consequently, N. zanardinii was selected for subsequent extraction and application studies. Alginate extraction efficiency was 4.73 ± 0.38 g/100 g seaweed, demonstrating moderate antioxidant properties. The extracts effectively inhibited shrimp polyphenol oxidase, with 2% phlorotannins + 1% alginate showing 84.51% inhibition. When applied to shrimp, this combination significantly delayed melanosis development, suppressed microbial growth, and maintained lower pH, total volatile basic nitrogen (TVB-N), and lipid oxidation values during 16 days of ice storage compared to untreated controls. Sensory evaluation confirmed better retention of quality attributes in treated shrimp. These findings demonstrate the potential of N. zanardinii phlorotannin–alginate extracts as effective natural preservatives for maintaining shrimp quality during cold storage, offering a sustainable alternative to synthetic additives in seafood processing. Full article

Seaweed holds significant promise as a renewable feedstock for bioenergy due to its rapid growth, carbon sequestration capacity, and non-competition with terrestrial agriculture. This review examines recent progress in multi-method synergies for optimized energy conversion from seaweed biomass. Physical pre-treatments (e.g., drying, milling, ultrasound, microwave) enhance substrate accessibility but face energy intensity constraints. Chemical processes (acid/alkali, solvent extraction, catalysis) improve lipid/sugar recovery and bio-oil yields, especially via hydrodeoxygenation (HDO) and catalytic cracking over tailored catalysts (e.g., ZSM-5), though cost and byproduct management remain challenges. Biological methods (enzymatic hydrolysis, fermentation) enable eco-friendly valorization but suffer from scalability and enzymatic cost limitations. Critically, integrated approaches—such as microwave-solvent systems or hybrid thermochemical-biological cascades—demonstrate superior efficiency over singular techniques. Upgrading pathways for liquid bio-oil (e.g., HDO, catalytic pyrolysis) show considerable potential for drop-in fuel production, while solid-phase biochar and biogas offer carbon sequestration and circular economy benefits. Future priorities include developing low-cost catalysts, optimizing process economics, and scaling synergies like hydrothermal liquefaction coupled with catalytic upgrading to advance sustainable seaweed biorefineries. Full article

Marine macroalgae (seaweed) are a rich source of bioactive polysaccharides such as agar, carrageenan, and alginate. These three compounds are classified as food additive ingredients, widely used as gelling, thickening, stabilizing, and emulsifying agents in the food, nutraceutical, pharmaceutical, and cosmetic industries. However, the growing concern for a safer world has sparked renewed interest in their safety evaluation. Unlike synthetic compounds with specified structures, seaweed polysaccharides exhibit substantial structural heterogeneity due to variations in species, habitat, and processing, affecting bioactivity, digestibility, and interactions within the gastrointestinal tract. Although the safety of these compounds is generally accepted, there are still significant gaps in our understanding of their physicochemical behaviour. This highlights the need to develop a standardized digestion model to ensure their safety and evaluate their potential long-term health effects. Most of these compounds are only partially absorbed in the upper gastrointestinal tract, where they are fermented into metabolites with varying health effects. The safety of carrageenan, in particular, remains a subject of debate due to ambiguous results reported by various researchers’ groups. This review highlights the importance of adopting standardized digestion assays, integrated analytical tools, and multidisciplinary approaches. These are crucial for thoroughly evaluating the molecular integrity, metabolism, and biological impact of seaweed polysaccharides, which will ultimately support evidence-based regulatory frameworks and ensure their safe use in human nutrition. This critical analysis focuses on food safety and security, with a methodology that can be applied to other foods or compounds. Full article

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