Search Results (32)

The growing demand for sustainable and nutrient-rich food sources has positioned macroalgae as a promising alternative for food product development. This study investigates the extraction and characterization of hydrocolloids from three red macroalgae species (Chondrus crispus, Gracilaria gracilis, and Gelidium corneum) using water bath (WB), ultrasound (US), and hybrid ultrasound–water bath (USWB) treatments for 45 and 60 min. The physicochemical properties of the extracts, including rheological behavior, particle size distribution, antioxidant activity, and texture, were assessed. The results show that C. crispus produced the firmest gels due to its high carrageenan content, with WB and USWB treatments yielding the most stable gel structures. In contrast, G. gracilis and G. corneum exhibited lower gel strength, consistent with their agar composition. WB-treated samples demonstrated superior antioxidant retention, while US treatment was more effective in preserving color stability. The findings highlight macroalgae as a viable and sustainable alternative to conventional hydrocolloids, reinforcing their potential as natural gelling agents, thickeners, and stabilizers for the food and pharmaceutical industries. This study provides a comparative evaluation of WB, US, and USWB extraction methods, offering insights into optimizing hydrocolloid extraction for enhanced functionality and sustainability. Full article

This study is aimed at the development of a fermented cashew nut cheese alternative supplemented with Chondrus crispus and Porphyra sp. and the evaluation of the impact of seaweed supplementation through analysis of physicochemical, microbiological, and organoleptic properties of the developed food products. The total lipid content decreased with the supplementation with seaweeds. Crude protein content also slightly decreased, while elemental analysis showed that mineral and trace element (Ca, K, Mg, Na, Fe, I, Se, and Zn) content increased when C. crispus was added to the paste. The analyses of color and textural (TPA) attributes showed that these were significantly influenced by adding seaweeds to the cashew paste. Generally, the microbiological results comply with the different European guidelines for assessing the microbiological safety of ready-to-eat foods placed on the market, except for aerobic mesophilic bacteria and marine agar counts. Flash Profile analysis allowed for distinguishing sample attributes, showing an increased flavor complexity of the plant-based cheese alternatives supplemented with seaweeds. Overall, the study indicates that seaweed enrichment mainly influenced the physicochemical and sensory characteristics of plant-based cheese alternatives. Full article

This study investigates the nutritional composition and bioactive properties of Palmaria palmata (dulse), Ascophyllum nodosum (knotted wrack), and Chondrus crispus (Irish moss). Understanding the nutritional values of these seaweeds is very important due to their potential health benefits, especially their antioxidant properties and cytotoxic activities, which point to their ability to inhibit cancer cell proliferation. Comprehensive analyses were conducted to assess protein content, amino acid composition, mineral profile, fatty acids, polyphenols, total carotenoids, antioxidant activity, and cytotoxicity against cervical (HeLa), and colon (HCT-116) cell lines. P. palmata exhibited the highest protein content, while C. crispus was richest in calcium, iron, manganese, and zinc. Amino acid analysis revealed C. crispus as being particularly high in essential and non-essential amino acids, including alanine, glutamic acid, and glycine. A. nodosum and C. crispus were rich in polyunsaturated fatty acids (PUFAs), notably eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). A. nodosum showed the highest total carotenoid content. Polyphenol analysis highlighted the presence of compounds such as p-coumaric acid, gallic acid, and p-hydroxybenzoic acid across the species. Both the ethanolic and hexane A. nodosum extracts demonstrated the strongest antioxidant potential in DPPH^• and ABTS⁺ assays. The cytotoxicity evaluation revealed high anticancer activity of A. nodosum and C. crispus hexane extract against HeLa and HCT-116, though it employed cell cycle arrest and apoptosis. A. nodosum hexane extract exhibited moderate selective anticancer activity against HCT-116. These findings underscore the nutritional diversity and potential health benefits of these macroalgae (seaweed) species, suggesting their suitability as functional foods or supplements, offering diverse nutritional and therapeutic benefits. Full article

Lipoxygenases (LOXs) from lower organisms have substrate flexibility and function versatility in fatty acid oxidation, but it is not clear how these LOXs acquired the ability to execute multiple functions within only one catalytic domain. This work studied a multifunctional LOX from red alga Pyropia haitanensis (PhLOX) which combined hydroperoxidelyase (HPL) and allene oxide synthase (AOS) activity in its active pocket. Molecular docking and site-directed mutagenesis revealed that Phe642 and Phe826 jointly regulated the double peroxidation of fatty acid, Gln777 and Asn575 were essential to the AOS function, and the HPL activity was improved when Asn575, Gln777, or Phe826 was replaced by leucine. Phylogenetic analysis indicated that Asn575 and Phe826 were unique amino acid sites in the separated clades clustered with PhLOX, whereas Phe642 and Gln777 were conserved in plant or animal LOXs. The N-terminal START/RHO_alpha_C/PITP/Bet_v1/CoxG/CalC (SRPBCC) domain of PhLOX was another key variable, as the absence of this domain disrupted the versatility of PhLOX. Moreover, the functions of two homologous LOXs from marine bacterium Shewanella violacea and red alga Chondrus crispus were examined. The HPL activity of PhLOX appeared to be inherited from a common ancestor, and the AOS function was likely acquired through mutations in some key residues in the active pocket. Taken together, our results suggested that some LOXs from red algae attained their versatility by amalgamating functional domains of ancestral origin and unique amino acid mutations. Full article

It is proposed that prebiotic diet supplements improve intestinal function, in part by improving the barrier function of the intestinal epithelium with an associated increase in the expression of tight junction proteins, including occludin and zonula occludens-1 (ZO-1). We examined the expression of these proteins in two strains of laying hens (Lohman LSL-lite (White) and Lohman Brown-lite (Brown)) who were supplemented or not with 3% Chondrus crispus or 0.5% Ascophyllum nodosum seaweeds from 31 to 72 weeks of age. Occludin was localized to the lateral surfaces and across the intestinal epithelium in all animals. Reactivity for ZO-1 was concentrated at the apicolateral epithelial cell membrane border. Mood’s median test indicated that White hens may express more occludin in villus epithelium (median intensity 3.5 vs. 2.5 in Brown hens, p = 0.06) but less ZO-1 in the deep cryptal epithelium (median intensity 1.5 vs. 2.5 in Brown hens, p = 0.06). Western blotting also showed higher levels of occludin in White than Brown hens (p < 0.05). A decrease in ZO-1 Western blot expression was associated with Chondrus crispus supplementation in comparison to controls (p < 0.05), but not with Ascophyllum nodosum supplementation (p > 0.05). In conclusion, genetic strain and dietary seaweed supplements affect tight junction regulatory protein expression levels but do not impact the anatomical distribution, as seen in cryosections. Full article

Seaweeds, rich in high-value polysaccharides with thickening/gelling properties (e.g., agar, carrageenan, and alginate), are extensively used in the food industry for texture customization and enhancement. However, conventional extraction methods for these hydrocolloids often involve potentially hazardous chemicals and long extraction times. In this study, three red seaweed species (Chondrus crispus, Gelidium Corneum, and Gracilaria gracilis) commercialized as food ingredients by local companies were chosen for their native gelling biopolymers, which were extracted using water-based methodologies (i.e., (1) hydration at room temperature; (2) stirring at 90 °C; and (3) centrifugation at 40 °C) for production of sustainable food gels. The potential use of these extracts as bioinks was assessed employing an extrusion-based 3D printer. The present work aimed to study the gelation process, taken place during printing, and assess the effectiveness of the selected green extraction method in producing gels. To improve the definition of the printed gel, two critical printing parameters were investigated: the addition of locust bean gum (LBG) at different concentrations (0, 0.5, 1, 1.5, 2, and 2.5%) and printing temperature (30, 40, 60, and 80 °C). Rheological results from a controlled-stress rheometer indicated that gels derived from G. corneum and G. gracilis exhibited a lower gel strength (lower G′ and G″) and excessive material spreading during deposition (lower viscosity) than C. crispus. Thus, G′ was around 5 and 70 times higher for C. crispus gels than for G. corneum and G. gracilis, respectively. When increasing LBG concentration (0.5 to 2.5% w/w) and lowering the printing temperature (80 to 30 °C), an enhanced gel matrix definition for G. corneum and G. gracilis gels was found. In contrast, gels from C. crispus demonstrated greater stability and were less influenced by these parameters, showcasing the potential of the seaweed to develop sustainable clean label food gels. Eventually, these results highlight the feasibility of using algal-based extracts obtained through a green procedure as bioinks where LBG was employed as a synergic ingredient. Full article

Seaweed polysaccharides can act as substitutes for synthetic compounds present in commercial stimulants and fertilizers used in agriculture to improve crop yields and vigor. In this study, three different polysaccharides (alginate, agar, and carrageenan) were extracted from one brown seaweed, Saccorhiza polyschides, and two red seaweeds, Gracilaria gracilis and Chondrus crispus, respectively, and applied to potted turnip greens (Brassica napus L.), with the intention to analyze their impact on plant growth, development, and metabolism. Turnip greens treated with polysaccharides, especially carrageenan of C. crispus, showed the best results in improving the crop productivity in terms of plant length and weight, number of leaves, nutrient and pigment content, and soil fertility compared with turnip greens from the negative control or those treated with a commercial leaf fertilizer. λ-carrageenan extracted from the tetrasporophyte generation of C. crispus had the highest bioactivity and positive effect on turnip greens among all treatments. λ-carrageenan has been shown to improve plant growth; increase the plant’s biomass (plant leaves: CC(T) (40.80 ± 5.11 g) compared to the positive control (15.91 ± 15.15 g)) and root system; enhance photosynthetic activity; increase the uptake of soil nutrients; and protect plants against abiotic and biotic stresses, stimulating the production of secondary metabolites and managing its defense pathways. Seaweed-extracted polysaccharides have the potential to be used in sustainable agriculture. Full article

Macroalgae, particularly red seaweeds, have attracted significant attention due to their economic and health benefits. Chondrus, a red algae genus, despite its economic importance, seems to be undervalued. Among all its species, Chondrus crispus has been meticulously documented for its biological properties, and little is known about other species. No comprehensive review of the biological properties of this genus has been acknowledged. Thus, this review aimed to summarize the available information on the chemical constituents and biological properties of a few selected species, including Chondrus crispus, Chondrus ocellatus, Mazzaella canaliculata, and Chondrus armatus. We compiled and discovered that the genus is offering most of the important health-promoting benefits evidenced from in vitro and in vivo studies focused on antimicrobial, immunomodulation, neuroprotection, anti-atopic, anti-inflammatory, anti-viral, anti-diabetic, cytoprotective, antioxidant, anti-coagulation, nephroprotective, anti-tumor, and anti-venom activity, which speaks about the potential of this genus. Data on clinical studies are limited. Further, around 105 chemical constituents have been reported from Chondrus spp. Given its significance, further investigation is warranted, in the form of meticulously planned cell, animal, and clinical studies that concentrate on novel health-enhancing endeavors, in order to unveil the full potential of this genus. The review also outlines challenges and future directions. Full article

Contemporary climate change is increasing the occurrence of extreme weather events, heat waves being common examples. Here, we present visual evidence of mass bleaching in intertidal seaweeds following an unusually severe cold snap in Atlantic Canada. In February 2023, the air temperature on the Nova Scotia coast dropped below −20 °C for the first time in at least ten years. Such extreme temperatures lasted for several hours at low tide and were followed by extensive bleaching in whole thalli of the canopy-forming algae Chondrus crispus and Corallina officinalis. The loss of these foundation species might negatively impact intertidal biodiversity. Full article

With the notable scarcity of Chondrus crispus on the Portuguese coast, and interest in exploiting compounds such as carrageenan, this study focuses on investigating different aquaculture methods and recording the yield of carrageenan from specimens grown by different methods. We compare the growth of Chondrus crispus in aquaculture using Free Floating, Cages, Attempted Fixation on Rock, and Fixed Line similar to Long Line. The best method was Free Floating where Nursery 0 had a 24-day Specific Growth Rate (SGR) of 2.08 ± 0.47%/day. The worst method in terms of growth was Nursery 2 (Attempted Fixation on Rock) where the SGR at 28 days was 0.33 ± 0.69%/day, and no fixation was observed. In terms of carrageenan extraction, all culture methods gave rise to biomass that had a lower extraction yield than wild specimens, at 50.95 ± 4.10%. However, the Free-Floating method from Nursery 1 showed an acceptable carrageenan content (31.43 ± 7.00%). Therefore, we demonstrate that the concept of C. crispus cultivation may be key to promoting the sustainability and stability of this species. Full article

The application of seaweed extract-based biostimulants is a promising approach for achieving sustainable agriculture, with an enormous potential of improving crop yield and mitigating climate change effects. Abiotic stressors, such as drought, are major factors resulting in tomato (Solanum lycopersicum L.) yield losses and seaweed-based biostimulants have been proposed as an eco-friendly strategy to counteract this negative impact. Chondrus crispus is a common red seaweed widely used as source of carrageenans, not yet explored as a plant biostimulant. In this study, a protein hydrolysate-rich C. crispus extract, by-products of the carrageenan extraction, was tested on tomato plants under well-watered condition and water shortage. The foliar application of the protein-rich C. crispus extract conferred drought tolerance to tomato plants resulting in less noticeable visual stress symptoms. Treated plants showed higher shoot height and biomass under both well-watered and water deficit conditions, evidencing the double effect exerted by this new biostimulant, as plant growth promoter and drought stress protector. The treatment with the biostimulant had an effect on levels of abscisic acid and proline, and triggered the expression of Solyc02g084840, a drought marker gene. Finally, a label-free mass spectrometric approach allowed us to identify phycoerythrins and phycocyanins as major bioactive proteins contained in the extract. Altogether, these results indicate that the foliar application of protein hydrolysate-rich extracts from C. crispus improved tomato plant growth and tolerance to drought stress, suggesting a new opportunity for further applications in the agriculture and horticultural sectors. Full article

Novel personal care products are necessary to cope with the growing market demand for sustainable green products. In this context, this work deals with the formulation and fundamental physicochemical and rheological characterization of different natural personal care products using bioactive fractions from Chondrus crispus red macroalgae extracted under optimized green conditions. Body milks, body oils and shampoos were supplemented with soluble extracts with antioxidant features recovered after hydrothermal (200 °C) and microwave (170 °C)- and ultrasound (80 °C)-assisted extraction of the red macroalgae used as raw material. Formulated products were also compared with those prepared using (±)-α-tocopherol and butylhydroxytoluene standards. Body scrubs were formulated with the remaining solids (<2.25%) after microwave hydrodiffusion and gravidity treatment of the macroalgae. Results indicated that selected extracts provided personal care products with similar or even better physicochemical, color and viscous features than those supplemented with (±)-α-tocopherol or butylhydroxytoluene commercial antioxidants. Rheological profiles indicated that it is possible to develop personal care products with adequate viscous behavior (10²–10⁵ mPa s, at 1 s⁻¹), comparable with their synthetic counterparts. To conclude, the addition of antioxidant extracts led to lower apparent viscosity values suggesting an advantage from the skin applicability point of view, jointly with the absence of both the hysteresis phenomenon and water syneresis of the proposed formulations. Full article

The use of seaweed as a source of bioactive extracts has received increased attention from the market in recent years—particularly for nutraceutical applications. In this context, this study evaluated the nutraceutical application of seaweed biomass and extracts from three seaweeds from Portugal: Ulva sp., Laminaria ochroleuca, and Chondrus crispus. For each of the said seaweeds, four different extracts were obtained using GRAS solvents—acetone (A), ethanol (E), ethanol–water (1:1) (EW), and one polysaccharide-rich extract (P) using water and further precipitation with ethanol. The bioactive potential of the extracts was assessed in terms of antioxidant capacity (ABTS^•+, DPPH^•, ^•NO, O₂^•− scavenging, and ORAC-FL assay) and anti-inflammatory capacity (COX inhibition and human red blood cell membrane stabilisation). Furthermore, the biochemical profile was determined for the raw biomass and extracts to better comprehend their possible applications as nutraceuticals. The results show that all extracts have antioxidant potential. Five extracts (L. ochroleuca E, EW, and P and Ulva sp. E and P) showed anti-inflammatory capacity. Overall, L. ochroleuca EW extract exhibited the most promising potential as both an antioxidant and anti-inflammatory and is an interesting candidate nutraceutical ingredient. Full article

This study reports on the green and cost-efficient synthesis of gold nanoparticles from three different red algae extracts. The nanoparticles synthesized were fully characterized by UV-Vis spectroscopy, HRTEM, and Z-potential. Relevant components occurring in the extracts, such as polysaccharides or phenolic content, were assessed by analytical techniques such as spectrophotometric assays and liquid chromatography. Finally, the antioxidant, antitumoral, and anti-inflammatory potential of both the extracts and the gold nanoparticles synthesized were analyzed in order to determine a possible synergistic effect on the nanoparticles. The results obtained confirmed the obtainment of gold nanoparticles with significant potential as immunotherapeutic agents. The therapeutic potential of these nanoparticles could be higher than that of inert gold nanoparticles loaded with bioactive molecules since the former would allow for higher accumulation into the targeted tissue. Full article

To better understand the migration properties of hybrid carrageenan from the seaweed tissue during carrageenan extraction, the effect of increasing the seaweed surface area by the mechanical disintegration of gametophyte Chondrus crispus chips was studied under various temperature and time extraction conditions. Dried Chondrus crispus seaweed chips were milled by a rotor beater mill and classified into eight different size fractions by sieving with varying mesh sizes from 50 to 2000 μm. During extraction at 22 °C, the red color of the filtrate increased significantly with the decreasing particle size of the fraction, correlating with the increasing phycoerythrin concentration (from 0.26 mg PE/g dry seaweed in the >2000 μm size fraction to 2.30 mg PE/g dry seaweed in the <50 μm size fraction). On the other hand, under the same extraction conditions, only a small increase in carrageenan precipitate was obtained with the decreasing size fractions (from no recovery in the >2000 μm size fraction to 2.1 ± 0.1 g/kg filtrate in the <50 μm size fraction). This yield was significantly lower than the ones from extractions at 45 °C (5.4 ± 0.1 g/kg) or at 90 °C (9.9 ± 2.1 g/kg) for the same particle size and time conditions. It could be concluded that hybrid carrageenan extraction is not surface area dependent, while phycoerythrin is. Therefore, it seems that phycoerythrin and carrageenan extraction follow different mechanisms. This creates potential for the selective extraction of each of those two compounds. Full article