Palmaria Palmata Research Articles

Seaweed Nutritional Value and Bioactive Properties: Insights from Ascophyllum nodosum, Palmaria palmata, and Chondrus crispus.

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.

Potential Use of Algae and Seaweed Extracts as Protection Against Peach Leaf Curl

Abstract Plant pathogenic fungi are a major cause of plant diseases, contributing significantly to the global decline in food production. Their proliferation results in substantial crop losses, fruit and vegetable deterioration, reduced food accessibility, and billions of dollars in economic losses annually. While synthetic chemical fungicides are commonly used to combat fungal diseases, their environmental impact is concerning. Marine algae provide a sustainable alternative, offering diverse compounds with industrial applications and presenting an eco-friendly solution. Taphrina deformans is responsible for peach leaf curl, a widespread disease in peach trees that can severely impact crop productivity and tree lifespan. Seaweeds and algae, encountering various biological interactions and extreme abiotic conditions, have evolved defense mechanisms, including the production of biologically active substances. In our study, we investigated the efficacy of water extracts from six algae (Nannochloropsis sp., Tetraselmis chuii, Chaetoceros muelleri, Thalassiosira weissflogii, Tisochrysis lutea, Chlorella vulgaris), four seaweeds (Palmaria palmata, Chondrus crispus, Ascophyllum nodosum), and one cyanobacterium (Arthrospira platensis) at two different concentrations (1% and 3%) in suppressing the outbreak of peach leaf curl disease in vivo on peach trees. The spray was applied twice in spring just before budbreak. Algae and seaweed extracts showed significant suppression of peach leaf curl outbreaks on peach trees compared to controls. Following the application of water extract of Chlorella vulgaris at both concentrations, the lowest incidences of symptomatic disease expression were observed (1.00 ±0.00% and 0.25 ±0.50%). Algae and seaweed extracts demonstrate potential in controlling leaf curl disease in peach trees.

Development of a novel renewable energy-based integrated system coupling biomass and H2S sources for clean hydrogen production

The present work aims to develop a novel integrated energy system to produce clean hydrogen, power, and biochar. The Palmaria palmata, a type of seaweed, and hydrogen sulfide from the industrial gaseous waste streams are taken as potential feedstock. A combined thermochemical approach is employed for the processing of both feedstocks. For clean hydrogen production, the zinc sulfide thermochemical cycle is employed. Both stoichiometric and non-stoichiometric equilibrium-based models of the proposed plant design are developed in the Aspen Plus software, and a comprehensive thermodynamic analysis of the system is also performed by evaluating energy and exergy efficiencies. The study further explores and covers the modeling, simulation, and parametric analyses of various subsections to enhance the hydrogen and biochar production rate. The parametric analyses show that the first step of the thermochemical cycle (desulfurization reaction) follows a stoichiometric pathway and the optimal conversion is achieved at a ZnO/H2S ratio equal to 1. On the other hand, the second step of the thermochemical cycle (regeneration reaction) does not follow a stoichiometric pathway, and ZnS conversion of 12.87 % is achieved at a high temperature of 1400 °C. It is found that a hydrogen production rate of 0.71 mol/s is achieved with the introduction of 0.27 mol/s of H2S. The energy and exergy efficiencies of the zinc sulfide thermochemical cycle are found to be 65.23 % and 35.58 % respectively. A biochar production rate of 0.024 kg/s is obtained with the Palmaria palmata feed rate of 0.097 kg/s. The Palmaria to biochar energy and exergy efficiencies are found to be 55.43 % and 45.91 % respectively. The overall energy and exergy efficiencies of the proposed plant are determined to be 72.88 % and 50.03 % respectively.

New Green Biorefinery Strategies to Valorize Bioactive Fractions from Palmaria palmata.

A biorefinery process was developed to isolate phycobiliproteins, sulfated polysaccharides, and phenolic compounds from Palmaria palmata. The extraction process was carried out in three stages using ultrasound-assisted extraction (UAE) and pressurized liquid extraction (PLE) integrated with different natural deep eutectic solvents (NaDESs). In general, PLE provided higher phycobiliprotein contents than UAE in the first step of the process. In fact, the hydrolysis product of the PLE-NaDES extracts achieved a higher antioxidant capacity than that of the UAE-NaDES extracts. Particularly, glycerol:glucose (2:1) with 50% water in combination with PLE was the most suitable NaDES to recover the highest phycobiliprotein, protein, and sulfated polysaccharide contents from Palmaria palmata in the first and second steps of the biorefinery process. Finally, a PLE-NaDES using choline chloride:glycerol (1:2) with 60% water as the NaDES was employed for the recovery of antioxidant and neuroprotective phenolic compounds from the residue of the second step, obtaining a higher total phenolic content than employing PLE with ethanol/water (70:30, v/v) as the extraction solvent. Moreover, a forced stability study revealed that the NaDESs provided a protective effect compared to the water extracts against the degradation of phycobiliproteins, preserving their color over time. This study contributes to the recovery of high-value components from an undervalued biomarine source through a sustainable biorefinery process.

Impact of alkaline solution, carbohydrase and biomass:solvent on extraction efficiency, and protein and amino acid profiles of Palmaria palmata protein extracts

The impact of using different alkaline solutions, carbohydrases and changing the biomass to solvent volume ratio (biomass:solvent) on protein content, protein and biomass yield recovery in protein enriched extracts from Palmaria palmata (red seaweed) was studied. Protein extraction with alkaline solutions, i.e., NaOH, KOH, Ca(OH)2 and Na2CO3 (at 0.12 M) along with (and without) carbohydrases B, BD and L (containing xylanase, a mixture of xylanase and cellulase, and a combination of cellulase, xylanase and polygalacturonase activities, respectively) was assessed. Principal component analysis was used to assess correlations (if any) between the different alkaline solvents, carbohydrases and changing biomass:solvent on extraction efficiency. The highest protein content (56.64 ± 0.43 % (w/w)) was obtained using KOH assisted extraction with carbohydrase BD. The highest protein and biomass yield recoveries (70.65 ± 1.38 and 21.99 ± 0.43 % (w/w), respectively) were obtained on extraction using NaOH assisted with carbohydrases BD. Electrophoretic, amino acid profile and amino acid score analyses displayed differences depending on the alkaline solvent used for protein extraction. Appropriate selection of the alkaline solvent, carbohydrase and biomass:volume combination during protein extraction can contribute to the production of compositionally enhanced high-quality protein concentrates from P. palmata.

Marine Bioactives in Cancer Prevention and Treatment

The twice high incidence risk of cancer in men was the reason for over a million new cases and deaths recorded globally in 2018. The two most frequent cancer-related fatalities are lung and breast cancer. Novel therapies have been made possible by developments in immunotherapy, biology, and pharmaceutical design. Novel cancer prevention and therapy elements are being made possible by technological advancements and studies on marine natural resources. The creation of innovative anticancer medications is utilizing marine-derived natural products (MNPs). Biologically active polyketides, high molecular weight organic sugars, terpenes, bioengineered alkaloids, and marine animal peptides are some examples of these MNPs. Anticancer drugs are also developed with the help of plants, animals, invertebrates, and microbes found on land. The National Cancer Institute is exploring the potential of nutrition and food in cancer prevention despite the absence of preclinical and clinical data. Marine organisms contain bioactive compounds that have potential anticancer effects. Polyphenols, polysaccharides, and alkaloids are some of the active components found in marine species. Polyphenols, found in edible seaweeds like Palmaria palmata, can lower cancer cell division and proliferation, while polysaccharides trigger the innate immune system, causing apoptosis in pancreatic islet cancer and human leukemia cells. Alkaloids, derived from marine sources, can inhibit cancer cell development. Peptides, found in various plant species, have shown cytotoxic effects on several human cell lines, including pancreatic, breast, lung, and bladder cancers. Marine drug approval faces challenges like the possibility of a resurgence of different metabolites due to environmental conditions and limited lead compound availability.

Assessment of the antibacterial and antioxidant activities of seaweed-derived extracts

In swine farming, animals develop diseases that require the use of antibiotics. In-feed antibiotics as growth promoters have been banned due to the increasing concern of antimicrobial resistance. Seaweeds offer bioactive molecules with antibacterial and antioxidant properties. The aim was to estimate the in vitro properties of seaweed extracts: Ascophyllum nodosum (AN), Palmaria palmata (PP), Ulva lactuca (UL), and 1:1 mixes (ANPP, ANUL, PPUL). Escherichia coli strains were used to test for growth inhibitory activity, and chemical-based assays were performed for antioxidant properties. The treatments were 2 (with/without Escherichia coli) × 2 (F4 + and F18 +) × 5 doses (0, 1.44, 2.87, 5.75, 11.50, and 23.0 mg/mL). Bacteria were supplemented with seaweed extracts, and growth was monitored. The antioxidant activity was assessed with 6 doses (0, 1, 50, 100, 200, 500, and 600 mg/mL) × 6 compounds using two chemical assays. Data were evaluated through SAS. The results showed that AN and UL significantly inhibited (p < 0.05) the growth of F4 + and F18 +. PP and mixes did not display an inhibition of the bacteria growth. AN, PP, UL extracts, and mixes exhibited antioxidant activities, with AN showing the strongest dose–response. Thus, AN and UL seaweed extracts reveal promising antibacterial and antioxidant effects and may be candidates for in-feed additives.

Bioaccumulation, biodistribution, and transformation of polyvinylpyrrolidone-coated silver nanoparticles in edible seaweeds

Seaweeds are recognised as a potential eco-friendly food source. However, some species have shown the capacity to bioaccumulate many substances of diverse nature, such as inorganic nanoparticles (NPs), which may have potentially harmful effects on them. Among these NPs, silver nanoparticles (AgNPs) have been used to enhance the antifungal and antibacterial properties of the final consumer products, such as textiles and food packages. Their potential release into the aquatic environment raises significant concern, increasing the probability of interaction with aquatic biota, such as macroalgae.In this work, we investigated the differences in bioaccumulation, biodistribution, and transformation of NPs as a function of seaweed species. We selected polyvinylpyrrolidone-coated silver nanoparticles (PVP-AgNPs) as model NP since they remain colloidally stable in seawater, focusing the study only on single particles and not on aggregates. The study was conducted on two different seaweed species with high commercial interest and value as human food: the red seaweed Palmaria palmata and the green seaweed Ulva fenestrata. Single-particle inductively coupled plasma mass spectroscopy (spICP-MS) analysis showed high and similar bioaccumulation of PVP-AgNPs in both seaweeds, in the range of 109 NPs/g of seaweed. However, electron microscopy with energy-dispersive X-ray analysis demonstrated that their time-dependent distribution and transformation in the algal tissue, mainly dissolution and formation of sulfur-rich corona and/or sulfidation, highly depended on the seaweed type.These results indicate that special attention should be given to the presence and transformation of AgNPs in seaweeds intended for human consumption. Not only the dissolution degree but also the speciation of these NPs could heavily impact their bioaccessibility, bioavailability, biodistribution, and toxicity to humans after ingestion.

Biorefinery of red seaweed Palmaria palmata for production of bio-based chemicals and biofuels

The seaweed Palmaria palmata was used as feedstock for production of chemical/fuel precursors (acetone, butanol, ethanol) and biogas. Palmaria palmata consists of xylan as major cell wall polysaccharide, as well as galactan and glucan. First, the biomass was subjected to acid hydrolysis at laboratory scale to solubilise fermentable sugars using acetic or hydrochloric acid as catalysts. Differences were observed in composition and amenability to hydrolysis of seaweeds from different harvests. Highest saccharification yields were obtained using HCl (pH 1.7, 120 °C, up to 80 % of xylose). Hydrolysates were fermented to acetone-butanol-ethanol by Clostridium beijerinckii reaching yields of 0.28 g products/g consumed sugars. The process by-products (solids after acetic acid hydrolysis and spent fermentation broth) were used as feedstocks for anaerobic digestion showing biogas yields between 310 and 650 L/kg dry organic material when mixed in different ratios with sugar beet pulp. Subsequently, the hydrolysis and fermentation processes were upscaled up to a 100-L pilot volume where nanofiltration was implemented to increase sugar concentration and remove salts. While high monomeric sugar yields were replicated during upscaling, fermentation inhibition was observed in the upscaled process. This paper shows Palmaria palmata to be a suitable feedstock for the co-production of bio-butanol and biogas and highlights process development needs to desalt and detoxify seaweed hydrolysates prior to fermentation.

A critical review of the edible seaweed Palmaria palmata (L.) Weber & Mohr and its bioactive compounds in the “omics” era

The red alga Palmaria palmata (“dulse”; Palmariaceae, Rhodophyta) has been used as food since the fifth century, especially in the North Atlantic region. Dulse is a good alternative to cereals due to its high nutritional profile. A critical review based on scientific and grey literature of dulse bioactive compounds and their activity identified key knowledge gaps. The review synthesis emphasizes the importance of species delimitation, microbial community characterization and multi-omics in the research of P. palmata. Recent advances and uncertainty in delimitating P. palmata are introduced in a phylogenetic context, and recommendations are given for future phytochemical studies. We refer to the concept of “seaweed holobiont” as the functional entity encompassing the seaweed and its associated microbiota, and call for action to characterize the microbial communities, since their interactions with the environment and seaweeds are important in seaweed well-being and postharvest quality changes (e.g. microbial spoilage and degradation of algal matrices). Finally, we discuss the status and trends of using multi-omics to address important research questions of P. palmata, and to help us understand the source, biosynthesis and function of its bioactive compounds.

Purification and Screening of the Antialgal Activity of Seaweed Extracts and a New Glycolipid Derivative against Two Ichthyotoxic Red Tide Microalgae Amphidinium carterae and Karenia mikimotoi.

Ichthyotoxic red tide is a problem that the world is facing and needs to solve. The use of antialgal compounds from marine macroalgae to suppress ichthyotoxic red tide is considered a promising biological control method. Antialgal substances were screened and isolated from Bangia fusco-purpurea, Gelidium amansii, Gloiopeltis furcate, Hizikia fusifarme, Laminaria japonica, Palmaria palmata, and Sargassum sp. to obtain new materials for the development of algaecides against ichthyotoxic red tide microalgae using bioactivity-guided isolation methods. The fractions of seven macroalgae exhibited selective inhibitory activities against Amphidinium carterae and Karenia mikimotoi, of which the ethyl acetate fractions had the strongest and broadest antialgal activities for the two tested red tide microalgae. Their inhibitory effects on A. carterae and K. mikimotoi were even stronger than that of potassium dichromate, such as ethyl acetate fractions of B. purpurea, H. fusifarme, and Sargassum sp. Thin-layer chromatography and ultraviolet spectroscopy were further carried out to screen the ethyl acetate fraction of Sargassum sp. Finally, a new glycolipid derivative, 2-O-eicosanoyl-3-O-(6-amino-6-deoxy)-β-D-glucopyranosyl-glycerol, was isolated and identified from Sargassum sp., and it was isolated for the first time from marine macroalgae. The significant antialgal effects of 2-O-eicosanoyl-3-O-(6-amino-6-deoxy)-β-D-glucopyranosyl-glycerol on A. carterae and K. mikimotoi were determined.

Effects of vegetative propagation on protein content and bioactivity of the red seaweed Palmaria palmata

Production of the red seaweed Palmaria palmata is currently hindered by a lack of standardised cultivation methods leading to uncertainties in yield and product quality. This study assessed vegetative propagation of meristematic fragments and the protein content and bioactivity potential of resulting plants. Growth was strong and sustained, averaging 5% day−1. Total protein contents initially decreased but recovered as the fragments grew larger and thicker. Samples displayed the highest antioxidant activity early in the experiment, suggesting that wounds may increase the secretion of antioxidant compounds. In silico analysis identified 762 potentially bioactive motifs, including 70 matching in vitro results. The newly discovered peptide SLLYSDITRPGGNMYTTR (SR18), linked to the pigment allophycocyanin, had very strong antioxidant properties and may drive the recorded in vitro activity. Vegetative propagation appears as a strong potential cultivation tool, and the utilised approach can be applied to assess the cultivation and nutritional potential of other seaweed species.

Macroalgae as Alkalizing Marine Drugs with a Low Potential Renal Acid Load

A growing interest in more sustainable and alternative food sources has brought seaweed and macroalgae to the spotlight for the general worldwide cuisine. Algae are often praised for their high nutritional value and are rich in potassium, calcium, and magnesium. Abundant in base precursors, algae are particularly interesting from an acid-base perspective. Their unique biochemical composition suggests a low potential renal acid load (PRAL), which is a commonly used estimate for the amount of acid or base a certain food produces in humans. Here, we analyzed the PRAL value of n = 106 macroalgae. Results suggested a strong alkalizing potential, with a mean PRAL value of −86.76 mEq/100 g. The lowest PRAL values were found for Laminaria ochroleuca (−286.78 mEq/100 g), Gelidium micropterum (−268.46 mEq/100 g), and Palmaria palmata (−259.16 mEq/100 g). We observed a strong inverse relationship of PRAL with algae’s potassium content (Spearman’s rho = −0.79, p&lt;0.001) and a moderate relationship with algae’s calcium content (Spearmen’s rho: −0.34, p&lt;0.001). Our data point at a potential role for several macroalgae as potent alkalizing marine drugs and suggest that a 10 g edible portion of some algae alone could contribute to a substantial PRAL reduction of up to −28.68 mEq. This might be of particular importance for individuals who benefit from a more alkaline diet and warrants further investigation in future studies.

Flavour characterization of twelve species of edible algae

Integration of algae as ingredients in food products may contribute to the flavour characteristics, on top of providing nutritional requirements. In this study, characterization of the volatile and non-volatile flavour compounds was performed on 12 species of macroalgae and microalgae representing various groups of algae. Nine macroalgae species from three divisions were selected, namely Phaeophyta (brown alga): Laminaria japonica, Undaria pinnatifida, Sargassum fusiforme and Fucus vesiculosus; Rhodophyta (red alga): Porphyra haitanensis, Porphyra yezoensis, Palmaria palmata and Gelidium amansii, and Chlorophyta (green alga): Ulva lactuca. In addition, three microalgae species include Arthrospira platensis, Chlorella vulgaris and Dunaliella salina. Volatile compounds were analysed by solid-phase microextraction (SPME) and gas chromatography–mass spectrometry-flame ionization detector (GC–MS/FID). Amino acids and nucleotides were analysed using amino acid analyser and high-performance liquid chromatography (HPLC) respectively. Based on the identified volatile and non-volatile compounds, no obvious trend was found within each group of algae. However, some algae variants have been found to contain a unique aroma profile of selected volatile and non-volatile compounds. D. salina was found to be high in volatile aldehydes, ketones, and alcohols, primarily products of carotenoid degradation. U. lactuca contains the highest volatile sulfur content, while F. vesiculosus was found to be high in aldehyde and alcohol compounds, which are potentially fishy odours. C. vulgaris was found to have the highest value of equivalent umami concentration (EUC) followed by roasted P. haitanensis, indicating that both algae have the highest umami potential. Lastly, microalgae species A. platensis and C. vulgaris contained the highest amounts of sulfurous tasting amino acids cysteine and methionine respectively.

Snacks from the sea: a cross-national comparison of consumer acceptance for crackers added with algae

One of the main priorities of current food systems is to develop new and healthy foods to overcome food shortages considering consumer’s expectations. Algae are receiving increasing attention as nutritious and sustainable food, though studies are limited mainly to Arthrospira and Chlorella species and cross-national research is scant. This study aims to investigate European consumers’ liking and perception of crackers added with powders from Arthrospira platensis (green Spirulina), isolated proteins from Arthrospira platensis (blue Spirulina), Palmaria palmata, Saccharina latissima, Lithothamnium calcareum and a control cracker. Belgian, German, Italian, and Swedish participants (n = 413, 18–69 years, 59.8% females) evaluated cracker liking and perceived sensory attributes using the check-all-that-apply (CATA) task. Food neophobia, familiarity towards, and consumption of algae were also collected. Partial Least Squares Regression (PLSR) analyses showed that across all countries, Lithothamnium calcareum, blue Spirulina and the control samples were perceived as similar and were liked more than the other crackers. “Sweet”, “toasted bread”, and “bland” attributes were significant contributors to liking, while “off-flavor”, “fishy flavor”, “umami” and “speckled” contributed negatively. PLSR performed by country provided similar results except for Italians who liked the green Spirulina sample equally as the samples added with Lithothamnium calcareum, blue Spirulina, and the control. These cross-national differences can be ascribed to Italians’ lower food neophobia level. The present results suggest that Lithothamnium calcareum is the most promising algal species to be exploited in food formulations and that the use of isolated proteins from Spirulina (blue Spirulina) significantly reduces off-flavors, consequently improving consumers’ acceptance.

Methylation-GC-MS/FID-Based Glycosidic Linkage Analysis of Unfractionated Polysaccharides in Red Seaweeds.

Glycosidic linkage analysis was conducted on the unfractionated polysaccharides in alcohol-insoluble residues (AIRs) prepared from six red seaweeds (Gracilariopsis sp., Prionitis sp., Mastocarpus papillatus, Callophyllis sp., Mazzaella splendens, and Palmaria palmata) using GC-MS/FID analysis of partially methylated alditol acetates (PMAAs). The cell walls of P. palmata primarily contained mixed-linkage xylans and small amounts of sulfated galactans and cellulose. In contrast, the unfractionated polysaccharides of the other five species were rich in galactans displaying diverse 3,6-anhydro-galactose and galactose linkages with varied sulfation patterns. Different levels of cellulose were also observed. This glycosidic linkage method offers advantages for cellulose analysis over traditional monosaccharide analysis that is known for underrepresenting glucose in crystalline cellulose. Relative linkage compositions calculated from GC-MS and GC-FID measurements showed that anhydro sugar linkages generated more responses in the latter detection method. This improved linkage workflow presents a useful tool for studying polysaccharide structural variations across red seaweed species. Furthermore, for the first time, relative linkage compositions from GC-MS and GC-FID measurements, along with normalized FID and total ion current (TIC) chromatograms without peak assignments, were analyzed using principal component analysis (PCA) as a proof-of-concept demonstration of the technique's potential to differentiate various red seaweed species.

Effect of Post-Extraction Ultrasonication on Compositional Features and Antioxidant Activities of Enzymatic/Alkaline Extracts of Palmaria palmata.

Palmaria palmata is a viable source of nutrients with bioactive properties. The present study determined the potential role of post-extraction ultrasonication on some compositional features and antioxidant properties of enzymatic/alkaline extracts of P. palmata (EAEP). No significant difference was detected in terms of protein content and recovery, as well as the amino acid composition of the extracts. The nitrogen-to-protein conversion factor of 5 was found to be too high for the seaweed and EAEP. The extracts sonicated by bath for 10 min and not sonicated showed the highest and lowest total phenolic contents (p < 0.05), respectively. The highest radical scavenging and lowest metal-chelating activities were observed for the non-sonicated sample, as evidenced by IC50 values. The extract sonicated by bath for 10 min showed the most favorable in vitro antioxidant properties since its radical scavenging was not significantly different from that of the not-sonicated sample (p > 0.05). In contrast, its metal-chelating activity was significantly higher (p < 0.05). To conclude, post-extraction ultrasonication by an ultrasonic bath for 10 min is recommended to increase phenolic content and improve the antioxidant properties of EAEP.

Tuning the extraction methodology targeting protein-enriched fractions from red algae

Alternative protein sources are being studied to substitute animal protein production and decrease the environmental issues that are inherent to the production of animal-based foods.This study investigates the potential of red macroalgae (Gracilaria verrucosa, Porphyra dioica, and Palmaria palmata) as an eco-friendly alternative protein source. Using the Osborne fractionation methodology, proteins were extracted under varying parameters (pH and grinding) and techniques (ultrasound and enzymatic extractions). Seaweed proteins exhibited a strong affinity for water and alkaline environments. Optimal extraction yields were obtained with H2O for G. verrucosa (33.24 ± 1.81 g protein/100 g algae protein) and P. palmata (29.56 ± 1.73 gprotein/100 galgae protein), while P. dioica showed highest yields with aqueous 0.1 M NaOH (26.28 ± 5.90 gprotein/100 galgae protein). Molecular weight patterns revealed aggregates (> 200 kDa) in G. verrucosa and P. palmata in the 0.1 M NaOH fraction. H2O extracts displayed peaks (48–84 kDa) linked to phycobiliproteins, showcasing good emulsifying properties. Solubility varied with solvents, with saline and 70 % EtOH dissolving lower molecular weight proteins. Aqueous 0.1 M NaOH extracts demonstrated promising texturizing capacity.Overall, proteins from red macroalgae show potential for food product development, offering an alternative with lower environmental impact compared to conventional animal-based proteins.

Assessing the potential of fluorescence as a monitoring tool for reproductive tissue in selected macroalgae species

Biofluorescence in certain seaweed species has been studied in association with their respective chlorophyll type and concentration. However, there is a paucity of information on the biofluorescent signature of macroalgal species at different life stages. Here we document that hyperspectral imaging differentiates between the fluorescent signatures of 5 macroalgal species (Ascophyllum nodosum, Fucus vesiculosus, Laminaria digitata, Palmaria palmata, and Saccharina latissima) collected from Tromsø, northern Norway (69-70 °N). Non-reproductive (NR) blades were collected for all species and reproductively mature blades (R) with sori were collected for three species. Hyperspectral imaging of collected blades was conducted under excitation lighting (~445 nm). We further assessed whether biofluorescence is reflected in the reproductive phenology of three selected species, L. digitata, P. palmata, and S. latissima. The spectral radiance of fluorescence emissions was found to be consistently different between R and NR blades. The greatest difference between R and NR blades was between the rhodophyte P. palmata (0.0075 W nm-1sr-1m-2 at 725 nm) followed by the phaeophytes L. digitata (0.03 W nm-1sr-1m-2 at 730-740 nm) and S. latissima (0.00225 W nm-1sr-1m-2 at 735-745 nm). Biofluorescence monitoring with hyperspectral imaging should be considered for further applicability in commercial seaweed operations.

The use of seaweed as sustainable feed ingredient for the house cricket (Acheta domesticus): investigating cricket performance and nutritional composition

Abstract The house cricket (Acheta domesticus) is considered one of the most promising farmed insect to be used as novel food, thanks to its attractive nutritional profile and its great taste. To the best of our knowledge, crickets in Europe are reared on soybean meal-rich feed which won’t be sustainable in the long run. Insect producers have shown interest in using more environmentally friendly substrates for cricket’s rearing. Among these, seaweed has been investigated as feed ingredients for insect rearing. However, no studies on crickets are available. We aimed to evaluate the potential use of the alga Palmaria palmata in the diet of house crickets (5%, 10% and 20% of the diet), in terms of insect performances and nutritional composition (protein, lipid, amino acids and fatty acids). Crickets fed seaweed-enriched diets showed good performance parameters (individual weight, cricket yield and survival) compared to crickets fed the control diet without presenting statistically significant differences (), while their nutritional composition changed significantly for some components. Protein content of the crickets increased when more seaweed was added to their diets (), while the fat content decreased (). Also, the amino acid composition of the crickets remained stable between dietary groups, except for histidine, methionine and lysine which increased in crickets fed more seaweed in the diet (, , , respectively). Finally, the presence of seaweed in the diet led to a transfer of the omega-3 eicosapentaenoic acid from the seaweed to the crickets (), which are naturally lacking this fatty acid. Based on this study, we conclude that the red alga Palmaria Palmata is a suitable substrate for cricket mass rearing up to 20 g/100 g of the diet. However, higher seaweed inclusion and longer dietary administration time could affect the nutritional composition of the house cricket differently, therefore they should be investigated.