Search Results (21)

Marine environments provide a unique opportunity to blend offshore wind energy production and marine fishery activities as complementary technologies. This study investigated the morphological characteristics (length and weight) and biomass yield of seaweed (Undaria pinnatifida) in a model marine environment with mariculture within an offshore wind farm in southwestern Korea. The mean lengths in the first cultivation trials of U. pinnatifida sporophytes increased from 1.8 ± 0.1 cm in November 2021 to 120–170 cm in March 2022 (density, 39.8 plants m⁻¹; final wet weight, 98.6–249.1 g (mean 146.8 ± 20.4 g, n = 20 ind.); yield 5842 g m⁻¹). Further, for the second cultivation trial, the length of the sporophytes increased from 1.5 ± 0.1 cm in November 2021 to 120–150 cm in April 2022 (density, 49.3 plants m⁻¹; final wet weight, 83.0–251.6 g (mean 155.7 ± 19.0 g; n = 20 ind.); yield, 7676 g m⁻¹), and, owing to the increase in water temperature and light intensity due to seasonal changes around the offshore wind power farm, the second cultivation trials showed signs of chlorosis. Considering the environment, we judged seaweed growth to be normal. Therefore, when applying this model to grow U. pinnatifida, seasonal temperature changes, the purpose of the product, and the nutritional status of the open-sea area should be considered. These results may improve seaweed farming in offshore wind farms in the future. Full article

With the growing use of crossbred cattle in Brazilian feedlots and increasing pressure to reduce antibiotic use as growth promoters, this study examines the impact of three feed additives—monensin (MON), monensin with Lithothamnium calcareum (LCM), and a blend of essential oils (BEO)—on the performance of Nellore (NEL) and crossbred (CROSS) cattle. A total of 90 Nellore and 90 crossbred bulls were assigned to a completely randomized block design with a 2 × 3 factorial design for 112 days, and all received the same diet with varying additives. Their methane (CH₄) emissions were estimated. All data were analyzed using the emmeans package of R software (version 4.4.1). Crossbred cattle outperformed Nellore in average daily gain (ADG), hot carcass weight (HCW), and dry matter intake (DMI), though feed efficiency remained unaffected. Across additives, no significant differences were observed in ADG, HCW, or dressing percentage. However, LCM had a lower DMI than the BEO, while MON showed better feed efficiency than the BEO. A breed-by-additive interaction trend was noted for DMI as a percentage of body weight (DMI%BW), with Nellore bulls on LCM diets showing the lowest DMI%BW. Crossbreeds had greater net energy (NE) requirements for maintenance (NEm) and gain (NEg), and MON-fed animals had greater NEm and NEg than the BEO. Crossbred bulls had greater daily methane (CH₄) emissions than Nellore bulls. Animals on the BEO had greater daily CH₄ emissions and greater g CH₄/kg metabolic BW than LCM bulls. In conclusion, the addition of Lithothamnium calcareum to monensin did not enhance performance compared to monensin alone. Monensin outperformed the BEO in feed efficiency and nutrient utilization. Full article

In order to enhance the application of thermoregulated materials, magnetic phase change microcapsules were prepared using a self-assembly method. Paraffin wax was chosen for its fine thermoregulation properties as the core material, while Fe₃O₄ nanoparticles doped in calcium carbonate served as the hybrid shell material. The microcapsules were then blended with sodium alginate and processed into seaweed fibers through wet spinning. The microstructure, thermal, and magnetic properties of the microcapsules were analyzed using scanning electron microscopy, energy dispersive X-ray spectroscopy, a laser particle size analyzer, an X-ray diffractometer, a differential scanning calorimeter, a thermogravimetric analyzer, and a vibrating sample magnetometer. The thermoregulation of the fibers was evaluated using a thermal infrared imager. The results indicated that the microcapsules had a uniform size distribution and good thermal properties. When the mass fraction of Fe₃O₄ nanoparticles was 8%, the microcapsules exhibited a saturation magnetization of 2.44 emu/g and an enthalpy value of 94.25 J/g, indicating effective phase change and magnetic properties. Furthermore, the thermoregulated seaweed fibers showed a high enthalpy value of 19.8 J/g with fine shape, offering potential for developing multifunctional fiber products. Full article

Ulva rigida green seaweed is an abundant biomass consisting of polysaccharides and protein mixtures and a potential bioresource for bioplastic food packaging. This research prepared and characterized novel biodegradable films from Ulva rigida extracts. The water-soluble fraction of Ulva rigida was extracted and prepared into bioplastic films. ¹H nuclear magnetic resonance indicated the presence of rhamnose, glucuronic and sulfate polysaccharides, while major amino acid components determined via high-performance liquid chromatography (HPLC) were aspartic acid, glutamic acid, alanine and glycine. Seaweed extracts were formulated with glycerol and triethyl citrate (20% and 30%) and prepared into films. Ulva rigida films showed non-homogeneous microstructures, as determined via scanning electron microscopy, due to immiscible crystalline component mixtures. X-ray diffraction also indicated modified crystalline morphology due to different plasticizers, while infrared spectra suggested interaction between plasticizers and Ulva rigida polymers via hydrogen bonding. The addition of glycerol decreased the glass transition temperature of the films from −36 °C for control films to −62 °C for films with 30% glycerol, indicating better plasticization. Water vapor and oxygen permeability were retained at up to 20% plasticizer content, and further addition of plasticizers increased the water permeability up to 6.5 g·mm/m²·day·KPa, while oxygen permeability decreased below 20 mL·mm/m²·day·atm when blending plasticizers at 30%. Adding glycerol efficiently improved tensile stress and strain by up to 4- and 3-fold, respectively. Glycerol-plasticized Ulva rigida extract films were produced as novel bio-based materials that supported sustainable food packaging. Full article

Hybrid carrageenans, also called kappa-2 (K2) or weak kappa, are a class of sulfated polysaccharides with thermo-reversible gelling properties in water and are extracted from a specific family of red seaweeds. K2 are known in the industry for their texturizing properties which are intermediate between those of kappa-carrageenans (K) and iota-carrageenans (I). As such, K2 are gaining industrial interest, as they can replace blends of K and I (K + I) in some niche applications. Over the last decade or so, some progress has been made in unravelling K2′s chemical structure. The understanding of K2 gel’s structure–rheological properties’ relationships has also improved. Such recent progress is reported here, reviewing the literature on gelling K2 published since the last review on the topic. The focus is on the seaweeds used for extracting K2, their block copolymer chemical structures, and how these impact on the gel’s formation and rheological properties. The outcome of this review is that additional rheological and structural studies of K2 hydrogels are needed, in particular to understand their viscoelastic behavior under large deformation and to unravel the differences between the texturizing properties of K2 and K + I. Full article

A blend refers to the combination of two or more components to achieve properties that are superior to those found in the individual products used for their production. Gracilaria birdiae agaran (SPGb) and chromium picolinate (ChrPic) are both antioxidant agents. However, there is no documentation of blends that incorporate agarans and ChrPic. Hence, the objective of this study was to generate blends containing SPGb and ChrPic that exhibit enhanced antioxidant activity compared to SPGb or ChrPic alone. ChrPic was commercially acquired, while SPGb was extracted from the seaweed. Five blends (B1; B2; B3; B4; B5) were produced, and tests indicated B5 as the best antioxidant blend. B5 was not cytotoxic or genotoxic. H₂O₂ (0.6 mM) induced toxicity in fibroblasts (3T3), and this effect was abolished by B5 (0.05 mg·mL⁻¹); neither ChrPic nor SPGb showed this effect. The cells also showed no signs of toxicity when exposed to H₂O₂ after being incubated with B5 and ChrPic for 24 h. In another experiment, cells were incubated with H₂O₂ and later exposed to SPGb, ChrPic, or B5. Again, SPGb was not effective, while cells exposed to ChrPic and B5 reduced MTT by 100%. The data demonstrated that B5 has activity superior to SPGb and ChrPic and points to B5 as a product to be used in future in vivo tests to confirm its antioxidant action. It may also be indicated as a possible nutraceutical agent. Full article

Current management for diabetes has stimulated the development of versatile 3D-based hydrogels as in vitro platforms for insulin release and as support for the encapsulation of pancreatic cells and islets of Langerhans. This work aimed to create agarose/fucoidan hydrogels to encapsulate pancreatic cells as a potential biomaterial for diabetes therapeutics. The hydrogels were produced by combining fucoidan (Fu) and agarose (Aga), marine polysaccharides derived from the cell wall of brown and red seaweeds, respectively, and a thermal gelation process. The agarose/fucoidan (AgaFu) blended hydrogels were obtained by dissolving Aga in 3 or 5 wt % Fu aqueous solutions to obtain different proportions (4:10; 5:10, and 7:10 wt). The rheological tests on hydrogels revealed a non-Newtonian and viscoelastic behavior, while the characterization confirmed the presence of the two polymers in the structure of the hydrogels. In addition, the mechanical behavior showed that increasing Aga concentrations resulted in hydrogels with higher Young’s modulus. Further, the ability of the developed materials to sustain the viability of human pancreatic cells was assessed by encapsulation of the 1.1B4HP cell line for up to 7 days. The biological assessment of the hydrogels revealed that cultured pancreatic beta cells tended to self-organize and form pseudo-islets during the period studied. Full article

Seaweed can be a desirable source of renewable energy or fuel after it has been processed by combustion, thermochemical conversion by gasification, pyrolysis, or hydrothermal liquefaction (HTL) or biochemical conversion routes like anaerobic digestion (AD). This work explores how well the measured properties of seaweed pellets match the specifications for the various fuel and energy conversion options listed. Blends of hay, wood chips, sawdust, and seaweed were pelletized. Eight pellet blends with dominant seaweed content and minimum acceptable mechanical strength and stability were produced and their physical and chemical properties were reported. The seaweed pellets had an energy content of around 14 MJ/kg, and each pellet could withstand almost 200 N of compression force. Their water content was around 5% or less and their ash content was around 20–34%. According to the results, a higher wood content increased the energy content of the pellets. Among those properties measured in this project, none of them contradicted the typical specifications of combustion, HTL, and AD. However, the low water content and low strength of some pellet types were unable to meet the specifications for certain types of gasification and pyrolysis. Full article

The current study assessed the effects of red macroalgae Asparagopsis taxiformis (AT)—included as an enteric methane inhibitor—in dairy cow diets on feed intake and eating–rumination behaviour. Fifteen early lactating Norwegian Red dairy cows were offered ad libitum access to drinking water and a total mixed ration (TMR) composed of 35% concentrate feed and 65% grass silage on a dry matter (DM) basis. The experiment lasted for 74 days with the first 22 days on a common diet used as the covariate period. At the end of the covariate period, the cows were randomly allocated into one of three dietary treatments: namely, 0% AT (control), 0.125% AT and 0.25% AT in the TMR. The TMR was offered in individual feed troughs with AT blended in a 400 g (w/w) water–molasses mixture. Eating–rumination behaviour was recorded for 11 days using RumiWatchSystem after feeding the experimental diets for 30 days. The 0.25% AT inclusion significantly reduced the DM intake (DMI). Time (min/d) spent on eating and eating in a head-down position increased with the increasing AT level in the diet, whereas rumination time was not affected. The greater time spent on eating head-down with the 0.25% AT group resulted in a significantly higher chewing index (min/kg DMI). Estimated saliva production per unit DMI (L/kg DMI, SE) increased from 10.9 (0.4) in the control to 11.3 (0.3) and 13.0 (0.3) in the 0.125% and 0.25% AT groups, respectively. This aligned with the measured ruminal fluid pH (6.09, 6.14, and 6.37 in the control, 0.125% AT and 0.25% AT groups, respectively). In conclusion, either the level of the water–molasses mixture used was not sufficient to mask the taste of AT, or the cows used it as a cue to sort out the AT. Studies with relatively larger numbers of animals and longer adaptation periods than what we used here, with varied modes of delivery of the seaweed may provide novel strategies for administering the additive in ruminant diets. Full article

Instant noodles are consumed worldwide, but instant noodles are often unhealthy. Therefore, in the current study, instant noodles were produced with composite flour (a blend of wheat flour and potato starch at weight ratios of 9:1, 8:2, and 7:3) incorporated with red seaweed powder (Eucheuma denticulatum) in proportions of 0, 5, 7.5, 10, 12.5, and 15%. The noodles’ sensory, physicochemical, and cooking properties were then determined. The incorporation of 7.5–15% of seaweed powder significantly (p < 0.05) increased the cooking yield, reduced the cooking loss, lengthened the cooking time, and decreased the pH values and water activity. The addition of seaweed powder weakened the tensile strength and softened the noodles. Seaweed noodles were denser and greener than control noodles. Among the three seaweed noodles (F2, F5, and F12) selected through the ranking test, panelists preferred F2 and F5 (both scoring 4.63 on a 7-point hedonic scale for overall acceptability) more than F12. Overall, F5 (at a wheat flour: potato starch ratio of 9:1; 15% seaweed powder) is the best-formulated seaweed noodle in this study, owing to its highest cooking yield and lowest cooking loss even with prolonged cooking, lowest water activity, and acceptable sensory qualities. Full article

Collagen hydrogels have been extensively applied in biomedical applications. However, their mechanical properties are insufficient for such applications. Our previous study showed improved mechanical properties when collagen was blended with alginate. The current study aims to analyze the physico-chemical properties of collagen-alginate (CA) films such as swelling, porosity, denaturation temperature (T_d), and rheology properties. Collagen was prepared from discarded fish skin of Ikan Belida (Notopterus lopis) that was derived from fish ball manufacturing industries and cross-linked with alginate from brown seaweed (Sargasum polycystum) of a local species as a means to benefit the downstream production of marine industries. CA hydrogels were fabricated with ratios (v/v) of 1:1, 1:4, 3:7, 4:1, and 7:3 respectively. FTIR spectrums of CA film showed an Amide I shift of 1636.12 cm⁻¹ to 1634.64 cm⁻¹, indicating collagen-alginate interactions. SEM images of CA films show a porous structure that varied from pure collagen. DSC analysis shows T_d was improved from 61.26 °C (collagen) to 83.11 °C (CA 3:7). CA 4:1 swelled nearly 800% after 48 h, correlated with the of hydrogels porosity. Most CA demonstrated visco-elastic solid characteristics with greater storage modulus (G′) than lost modulus (G″). Shear thinning and non-Newtonian behavior was observed in CA with 0.4% to 1.0% (w/v) CaCl₂. CA hydrogels that were derived from discarded materials shows promising potential to serve as a wound dressing or ink for bio printing in the future. Full article

The effect of several blending procedures between Ascophyllum nodosum seaweed flour (AF) and corn starch (CS) on the interactions between polyphenols and starch was studied in this paper. These methods comprised the blending of AF with native starch (NT) with previously gelled starch gel (GL) and promoting the gelling of corn starch in the presence of AF (CGL). Different AF–CS (g/g) ratios (from 1:0.5 to 1:25) were studied. The liquid phase was chemically characterized by polyphenols (TPC) and carbohydrates content. The antioxidant activity of the liquid phase after achieving the solid–liquid equilibrium was determined by DPPH, ABTS, and FRAP methods. The solid phase was characterized by FT-IR and SEM techniques. The Halsey model successfully fitted the equilibrium TPC in liquid and polyphenols adsorbed/retained by the solid phase of tested systems. NT samples showed lower polyphenols sorption than gelled samples. The differences found between samples obtained with GL and CGL methods suggested different interactions between polyphenols and starch. Specifically, physisorption is predominant in the case of the GL method, and molecular trapping of polyphenols in the starch gel structure is relevant for the CGL method. Results allowed us to determine the enhancement of the retention of polyphenols to achieve starchy foods with high bioactivity. Full article

The seaweed Rugulopteryx okamurae, from the Pacific Ocean, is considered an invasive species in the Mediterranean Sea. In this work, the use of this seaweed is proposed for the development of bio-based plastic materials (bioplastics) as a possible solution to the pollution produced by the plastic industry. The raw seaweed Rugulopteryx okamurae was firstly blended with glycerol (ratios: 50/50, 60/40 and 70/30), and subsequently, they were processed by injection molding at a mold temperature of 90, 120 and 150 °C. The rheological properties (frequency sweep tests and temperature ramp tests) were obtained for blends before and after processing by injection molding. The functional properties of the bioplastics were determined by the water uptake capacity (WUC) values and further scanning electron microscopy (SEM). The results obtained indicated that E’ was always greater than E”, which implies a predominantly elastic behavior. The 70/30 ratio presents higher values for both the viscoelastic moduli and tensile properties than the rest of the systems (186.53 ± 22.80 MPa and 2.61 ± 0.51 MPa, respectively). The WUC decreased with the increase in seaweed in the mixture, ranging from 262% for the 50/50 ratio to 181% for the 70/30 ratio. When carrying out the study on molded bioplastic 70/30 at different temperatures, the seaweed content did not exert a remarkable influence on the final properties of the bioplastics obtained. Thus, this invasive species could be used as raw material for the manufacture of environmentally friendly materials processed by injection molding, with several applications such as food packaging, control–release, etc. Full article

Seaweeds are considered healthy and sustainable food. Although their consumption is modest in Western countries, the demand for seaweed in food markets is increasing in Europe. Each seaweed species has unique nutritional and functional features. The preparation of blends, obtained by mixing several seaweeds species, allows the obtaining of maximum benefits and ingredients with single characteristics. In this work, five seaweed blends, commercially available and produced under organic conditions in Europe, were characterized. The proximal composition included contents of ash (20.28–28.68% DW), proteins (17.79–26.61% DW), lipids (0.55–1.50% DW), and total carbohydrates (39.47–47.37% DW). Fatty acid profiles were determined by gas chromatography–mass spectrometry (GC–MS), allowing quantification of healthy fatty acids, namely n-3 and n-6 polyunsaturated fatty acids (PUFA), and calculation of lipid quality indices. Each blend showed a characteristic PUFA content in the lipid pool (35.77–49.43% of total fatty acids) and the content in essential and healthy n-3 PUFA is highlighted. The atherogenicity (0.54–0.72) and thrombogenicity (0.23–0.45) indices evidenced a good nutritional value of lipid fractions. As nutritional and environmentally attractive products, the consumption of the studied seaweed blends can contribute to a healthy lifestyle. Full article

The effect of sargassum particle size on the final properties of sargassum-modified asphalt is investigated in this article. Seaweed sargassum particles were first obtained and characterized through elemental analysis, thermogravimetric analysis (TGA), X-ray diffraction, and FTIR spectroscopy. Additionally, pure and sargassum-modified asphalt blends were evaluated through physical and rheological tests such as penetration, softening point, thermal stability, dynamic viscosity, failure temperature, and epifluorescence microscopy. Modified asphalt blends were prepared by the hot mixing technique using different proportions of sargassum particles of two maximum sizes: 500 μm and 850 μm. Incorporating 3.0 wt.% of sargassum particles under 500 μm into the asphalt increased the viscosity of the original binder by a factor of 2.5 and its complex modulus by a factor of 1.9. At the same time, its failure temperature was 11 °C higher than the reference asphalt, which implies an improved viscoelastic behavior and rutting resistance at high temperatures. The study results suggest that the particles under 500 μm were responsible for the most significant effect on the final properties of the asphalt. Moreover, the storage stability test revealed that the modified asphalt blends are stable when the sargassum particle content was kept below 3.0 wt.%. The statistical analysis of the effect of sargassum particle size and concentration on the modified asphalt properties revealed that the rheological behavior is more affected by the modifier particle size; in contrast, the conventional physical properties were more determined by its concentration. Therefore, using low proportions of fine sargassum particles is efficient for improving the physical and rheological properties of the original asphalt, which is not only positive from the asphalt modification technology point of view but also from a sustainable perspective, since seaweed sargassum has become a useless plague in many coastal regions. Full article