Nutritional and antioxidant properties of different brown and red Spanish edible seaweeds

Biochemical Assessments of Six Species of Edible Coastal Algae Collected from Tabuk Region in Saudi Arabia

In the first study focusing on the Red Sea's Tabuk coast, six edible species of the most common algae were collected to evaluate their approximate composition using AOAC methods, amino acids using ion-exchange chromatography, minerals using atomic absorption spectroscopy, phenolic compounds using the Folin-Ciocalteu method, and ferric-reducing antioxidant power. All the data were significantly (p < 0.05) different among all the studied species. The data indicated that the protein content ranged from 9.25% for A. nodosum to 20.06% for H. musciformis. C. racemosa had the highest lipid content of 7.57%. Phosphors varied from 68.2 mg/100 g for A. nodosum to 406 mg/100 g for D. simplex. The largest amounts of calcium (2458 mg/100 g) and iron (29.79 mg/100 g) were found in C. racemosa. The total essential amino acids ranged between 38.16 and 46.82% for A. nodosum and D. simplex, respectively. F. vesiculosus had the maximum content of phenolic compounds (11.06 mg GAE/g). A. nodosum had the highest antioxidant capacity (1.78 mg TE/g). The research concluded that algae are the main effort toward sustainable agriculture to meet the world's food needs. that algae may be used to improve food naturally. To satisfy the criteria for sustainable food, which is one of the pillars of NEOM, numerous studies are required to investigate the natural products available in the Red Sea.

Seaweed and Seaweed-Based Functional Metabolites as Potential Modulators of Growth, Immune and Antioxidant Responses, and Gut Microbiota in Fish

Seaweed, also known as macroalgae, represents a vast resource that can be categorized into three taxonomic groups: Rhodophyta (red), Chlorophyta (green), and Phaeophyceae (brown). They are a good source of essential nutrients such as proteins, minerals, vitamins, and omega-3 fatty acids. Seaweed also contains a wide range of functional metabolites, including polyphenols, polysaccharides, and pigments. This study comprehensively discusses seaweed and seaweed-derived metabolites and their potential as a functional feed ingredient in aquafeed for aquaculture production. Past research has discussed the nutritional role of seaweed in promoting the growth performance of fish, but their effects on immune response and gut health in fish have received considerably less attention in the published literature. Existing research, however, has demonstrated that dietary seaweed and seaweed-based metabolite supplementation positively impact the antioxidant status, disease resistance, and stress response in fish. Additionally, seaweed supplementation can promote the growth of beneficial bacteria and inhibit the proliferation of harmful bacteria, thereby improving gut health and nutrient absorption in fish. Nevertheless, an important balance remains between dietary seaweed inclusion level and the resultant metabolic alteration in fish. This review highlights the current state of knowledge and the associated importance of continued research endeavors regarding seaweed and seaweed-based functional metabolites as potential modulators of growth, immune and antioxidant response, and gut microbiota composition in fish.

Algal nutraceuticals: A perspective on metabolic diversity, current food applications, and prospects in the field of metabolomics

The current consumers' demand for food naturalness is urging the search for new functional foods of natural origin with enhanced health-promoting properties. In this sense, algae constitute an underexplored biological source of nutraceuticals that can be used to fortify food products. Both marine macroalgae (or seaweeds) and microalgae exhibit a myriad of chemical constituents with associated features as a result of their primary and secondary metabolism. Thus, primary metabolites, especially polysaccharides and phycobiliproteins, present interesting properties to improve the rheological and nutritional properties of food matrices, whereas secondary metabolites, such as polyphenols and xanthophylls, may provide interesting bioactivities, including antioxidant or cytotoxic effects. Due to the interest in algae as a source of nutraceuticals by the food and related industries, novel strategies should be undertaken to add value to their derived functional components. As a result, metabolomics is considered a high throughput technology to get insight into the full metabolic profile of biological samples, and it opens a wide perspective in the study of algae metabolism, whose knowledge is still little explored. This review focuses on algae metabolism and its applications in the food industry, paying attention to the promising metabolomic approaches to be developed aiming at the functional characterization of these organisms.

Biological activity of algal derived carrageenan: A comprehensive review in light of human health and disease

Carrageenans are a family of natural linear sulfated polysaccharides derived from red seaweeds and used as a common food additive. Carrageenan's properties, impact on health, and aesthetic benefits have all been studied for a long time; however, the mechanisms are still unclear. In pharmaceutical aspects, carrageenan displayed potential antioxidant and immunomodulatory properties in both in vivo and in vitro action. It also contributes to potential disease-preventive activities through dynamic modulation of important intracellular signaling pathways, regulation of ROS buildup, and preservation of major cell survival and death processes which leads to potential drug development. Furthermore, the chemical synthesis of the current bioactive medicine with confirmational rearrangement may increase availability and bioactivity needs diligent examination. In this review, we give an up-to-date overview of recent research on Carrageenan with reference to health and therapeutic advantages. In addition, we have focused on structural conformation and its primary strategic deployment in disease prevention, as well as the mechanistic investigation of how it functions to combat various disease-preventive employed for future therapeutic interventions. This review may get new insights into the possible novel role of carrageenan and open up a novel disease-preventive mechanism and enhance human health.

Seaweed metabolomics: A review on its nutrients, bioactive compounds and changes in climate change

Seaweed, an important food resource in several Asian countries, contains various metabolites, including sugars, organic acids, and amino acids; however, their content is affected by prevailing environmental conditions. This review discusses seaweed metabolomics, especially the distribution of primary and functional secondary metabolites (e.g., carotenoids, polyphenols) in seaweed. Additionally, the effects of global warming on seaweed metabolite profile changes are discussed. For example, high temperatures can increase amino acid levels in seaweeds. Overall, understanding the effects of global warming on seaweed metabolite profiles can be useful for evaluating the nutritional composition of seaweeds as food. This review provides an overview of recent applications of metabolomics in seaweed research as well as a perspective on the nutrient content and cultivation of seaweeds under climate change scenarios.

Anti-Inflammatory Effects of Marine Bioactive Compounds and Their Potential as Functional Food Ingredients in the Prevention and Treatment of Neuroinflammatory Disorders

Functional foods include enhanced, enriched, fortified, or whole foods that impart health benefits beyond their nutritional value, particularly when consumed as part of a varied diet on a regular basis at effective levels. Marine sources can serve as the sources of various healthy foods and numerous functional food ingredients with biological effects can be derived from these sources. Microalgae, macroalgae, crustaceans, fungi, bacteria fish, and fish by-products are the most common marine sources that can provide many potential functional food ingredients including phenolic compounds, proteins and peptides, and polysaccharides. Neuroinflammation is closely linked with the initiation and progression of various neurodegenerative diseases, including Alzheimer's disease, Huntington's disease, and Parkinson's disease. Activation of astrocytes and microglia is a defense mechanism of the brain to counter damaged tissues and detrimental pathogens, wherein their chronic activation triggers neuroinflammation that can further exacerbate or induce neurodegeneration. Currently, available therapeutic agents only provide symptomatic relief from these disorders and no therapies are available to stop or slow down the advancement of neurodegeneration. Thereffore, natural compounds that can exert a protective effect against these disorders have therapeutic potential. Numerous chemical compounds, including bioactive peptides, fatty acids, pigments, alkaloids, and polysaccharides, have already been isolated from marine sources that show anti-inflammatory properties, which can be effective in the treatment and prevention of neuroinflammatory disorders. The anti-inflammatory potential of marine-derived compounds as functional food ingredients in the prevention and treatment of neurological disorders is covered in this review.

Effect of seaweed (Ecklonia cava extract) on blood glucose and insulin level on prediabetic patients: A double-blind randomized controlled trial

To investigate the effect of polyphenolic-rich seaweed extract (Ecklonia cava) on postprandial blood glucose (PPBG) and postprandial insulin level (PPIL) as well as investigating any associated side effects related to the study intervention in 20 prediabetic patients in Saudi Arabia. The double-blind, randomized-controlled trial was conducted from November 2020 to April 2021 in Riyadh, in 20 prediabetic patients with no other health complications. Subjects were given 600 mg of seaweed extract in a single dose for acute effect investigation. PPBG and PPIL were measured immediately at intervals of 30, 60, 90, and 120 min following 75 g of carbohydrate consumption, iAUC and peak concentration were calculated accordingly. Insignificant differences were shown for PPBG levels between study groups at intervals of 30 and 60 min (p > .05). However, PPBG results were significantly lower in the intervention group compared to placebo of 90 and 120 min after carbohydrate (75 g) consumption. The mean (SD) of PPBG in the seaweed group at 90 and 120 min was 108.1 (±8.9) and 101.3 (±8.7), respectively, compared to the placebo group at 90 and 120 min with a mean of 122.2 (±16.9) and 112.9 (±12.1), respectively (p value at 90 min = 0.032) and (p value at 120 min = 0.024). iAUC of PPBG shows no significant differences between the study groups (p > .05). There was no significant difference in PPIL between study groups at all study measurements (p > .05). Discomfort symptoms were similar between study groups (p > .05). This study indicated that a single dose of 600 mg of E. cava extract has a lowering effect on postprandial blood glucose with no associated side effects. Further research should investigate the glycemic modulating effects of marine algal extracts in the long-term investigation.

The significant value of sustainable cosmetics fragrance in the spotlight after COVID-19

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic has brought major changes to the world's population. This has led to increased wearing of masks to prevent infectious diseases, which can contribute to exacerbation of stress and the emergence of mental illness due to a physical health crisis.

OBJECTIVES

Therefore, this study comprehensively investigated the reasons why cosmetics customers pay attention to sustainable fragrances after COVID-19.

METHODS

This review article is a literature review, and a narrative review approach was used in this study. A total of 598 references were selected from 2004 to 2022 using representative journal search sites such as PubMed, Google Scholar, Scopus, and RISS. Among them, a total of 39 articles were successfully completed in this study using the PRISMA flowchart in the final stage.

RESULTS

In this study, by identifying the changes and needs of K-beauty and global cosmetics industry consumers who aspire for sustainable safety amid the COVID-19 pandemic, the increase in bad breath caused by the increase in mask wearing was recognized, and the need for fragrance due to mental health was recognized. Demand is expected to increase.

CONCLUSION

This study tried to change the perception of cosmetic fragrances into safe edible fragrances. Therefore, it is expected to be used as an important marketing material for the global cosmetics market.

Seaweed proteins are nutritionally valuable components in the human diet

The global population is expected to reach 11 billion people by the year 2100 and will require sustainable sources of dietary protein. Most dietary protein originates from animal and terrestrial plant agriculture, which leads to deforestation, water pollution, and greenhouse gas emissions. Discovering alternative protein sources that are nutritionally adequate for the human diet without harmful environmental effects is imperative. Seaweeds are a promising option as they produce abundant protein with a low carbon footprint. Experimental evidence shows that seaweeds contain high concentrations of the essential amino acids (EAAs) necessary for human consumption, but seaweeds have yet to be evaluated with standardized metrics to compare their nutritional value to other protein sources. In this technical note, independent literature describing the EAA content and protein digestibility of 3 commonly consumed species of seaweeds was evaluated alongside traditional protein sources using a novel hybrid protein quality (HPQ) metric. HPQ is derived from the protein digestibility-corrected amino acid score and digestibility indispensable amino acid score but includes modifications to address the lack of in vivo digestibility data for seaweeds. Seaweed proteins are similar in quality to common plant protein sources such as peas, soy, and tree nuts. Furthermore, seaweed proteins from different species have complementary EAA profiles and can be mixed to form protein blends that are nutritionally on par with animal products such as milk and whey. Thus, seaweeds may be viable protein sources with a reduced footprint that provide beneficial ecosystem services.

Multi-elemental Characterization of Semolina Samples by Inductively Coupled Plasma-Tandem Mass Spectrometry (ICP-MS/MS)

The precise characterization of the elemental composition of cereals and cereal products is becoming crucial to assess their nutritional values, geographical labeling, and also toxicological profile. Inductively coupled plasma-mass spectrometry (ICP-MS) has become popular for the elemental analysis of foods in recent years. Analytical performance of the inductively coupled plasma-tandem mass spectrometry (ICP-MS/MS) is improved with a reaction/collision cell that provides an interference-free analysis of most of the elements including phosphorus and sulfur. In this study, an analytical method was optimized for the quantification of 57 elements using ICP-MS/MS technique and validated for 25 elements that were available in certified reference materials (CRMs). Then, the mineral contents of semolina samples obtained from the durum wheat (Triticum durum) cultivars were analyzed according to the validation procedure. Recoveries of the elements were found in the range of 92-108% for the digested CRM. The method was robust for all elements and the results indicated good precision for the analytical method. The inter- and intra-day precision values were found below 5%, and in the range of 0.11-3.31% and 0.09-4.51%, respectively. Analyzed elements showed significant variability among the semolina samples. The variety and growing conditions might have influences on the elemental composition of semolina samples.

Phytochemical and Potential Properties of Seaweeds and Their Recent Applications: A Review

Since ancient times, seaweeds have been employed as source of highly bioactive secondary metabolites that could act as key medicinal components. Furthermore, research into the biological activity of certain seaweed compounds has progressed significantly, with an emphasis on their composition and application for human and animal nutrition. Seaweeds have many uses: they are consumed as fodder, and have been used in medicines, cosmetics, energy, fertilizers, and industrial agar and alginate biosynthesis. The beneficial effects of seaweed are mostly due to the presence of minerals, vitamins, phenols, polysaccharides, and sterols, as well as several other bioactive compounds. These compounds seem to have antioxidant, anti-inflammatory, anti-cancer, antimicrobial, and anti-diabetic activities. Recent advances and limitations for seaweed bioactive as a nutraceutical in terms of bioavailability are explored in order to better comprehend their therapeutic development. To further understand the mechanism of action of seaweed chemicals, more research is needed as is an investigation into their potential usage in pharmaceutical companies and other applications, with the ultimate objective of developing sustainable and healthier products. The objective of this review is to collect information about the role of seaweeds on nutritional, pharmacological, industrial, and biochemical applications, as well as their impact on human health.

Evaluation of the Biological Potential of Himanthalia elongata (L.) S.F.Gray and Eisenia bicyclis (Kjellman) Setchell Subcritical Water Extracts

Neuroprotection is a need that remains unmet in treating chronic neurodegenerative disorders, despite decades of extensive research. To find new neuroprotective compounds, extracts of Himanthalia elongata (L.) S.F.Gray and of Eisenia bicyclis (Kjellman) Setchell were obtained through subcritical water extraction applying a four-step temperature gradient. The fractions obtained were screened against brain enzymes involved in neurodegenerative etiology, namely in Alzheimer’s and Parkinson’s diseases, and against reactive oxygen and nitrogen species, all contributing factors to the progression of neurodegeneration. Results showed no significant enzyme inhibition but strong radical scavenging activities, particularly in the fourth fraction, extracted at the highest temperature (250 °C), highlighting their ability to retard oxidative and nitrosative stresses. At higher temperatures, fractions were composed of phenolic compounds and Maillard reaction products, a combination that contributed to their antioxidant activity and, consequently, their neuroprotective properties. All fractions were evaluated for the presence of iodine, 14 organochlorine and 7 organophosphorus pesticides, and pharmaceuticals used in Alzheimer’s and Parkinson’s diseases (14), psychiatric drugs (8), and metabolites (8). The fractions studied did not present any of the screened contaminants, and only fraction 1 of E. bicyclis should be used with caution due to iodine content.

Seaweeds as Ingredients to Lower Glycemic Potency of Cereal Foods Synergistically-A Perspective

Seaweeds are traditional food ingredients mainly in seaside regions. Modern food science and nutrition researchers have identified seaweed as a source of functional nutrients, such as dietary soluble and insoluble fibers, proteins, omega-3 fatty acids, prebiotic polysaccharides, polyphenols, and carotenoids. Owing to the rich nutrients, seaweeds and seaweed extract can be used as functional ingredients by modifying the nutrients composition to reduce the proportion of available carbohydrates, delaying the gastric emptying time and the absorption rate of glucose by increasing the digesta viscosity, and attenuating the digesting rate by blocking the activity of digestive enzymes. This review presents the concept of using seaweed as unconventional ingredients that can function synergistically to reduce the glycemic potency of cereal products.

The One-Health approach in seaweed food production

Seaweeds are rich in macronutrients, micronutrients, and bioactive components and have great potential as sustainable resources in terms of both production and consumption of a desirable food. Still, the seaweed aquaculture industry's rapid growth points out challenges that need to be taken into consideration when assessing environmental integrity, animal, and human health. In this review, the seaweed aquaculture's potential impact on the wildlife and human welfare and the environmental integrity has been evaluated using the One Health approach, a principle in which human, animal, and environmental health outcomes are considered as strictly connected. This is the first effort to implement the One Health concept into the seaweed cultivation assessment, and it is meant to give new perspectives for the growth of this industry.

An Assessment of Selected Nutritional, Bioactive, Thermal and Technological Properties of Brown and Red Irish Seaweed Species

Irish edible brown (Himanthalia elongata—sea spaghetti, Alaria esculenta—Irish wakame) and red seaweeds (Palmaria palmata—dulse, Porphyra umbilicalis—nori) were assessed for nutritional (proximate composition; salt; pH; amino acid; mineral and dietary fibre contents); bioactive (total phenolic content (TPC) and in vitro antioxidant activity (DPPH and FRAP)); thermal (thermogravimetric analysis (TGA)); and technological (water holding capacity (WHC), oil holding capacity (OHC) and swelling capacity (SC)) properties. Red seaweeds had higher (p < 0.05) protein levels, whereas brown seaweeds possessed higher (p < 0.05) moisture, ash, insoluble and total dietary fibre contents. Nori had the lowest (p < 0.05) salt level. Seaweed fat levels ranged from 1 to 2% DW. Aspartic and glutamic acids were the most abundant amino acids. The total amino acid (TAA) content ranged from 4.44 to 31.80%. Seaweeds contained numerous macro (e.g., Na) and trace minerals. The TPC, DPPH and FRAP activities followed the order: sea spaghetti ≥ nori > Irish wakame > dulse (p < 0.05). TGA indicated maximum weight loss at 250 °C. Dulse had the lowest (p < 0.05) WHC and SC properties. Dulse and nori had higher (p < 0.05) OHC than the brown seaweeds. Results demonstrate the potential of seaweeds as functional food product ingredients.

Current knowledge and future perspectives of the use of seaweeds for livestock production and meat quality: a systematic review

The effects of dietary macroalgae, or seaweeds, on growth performance and meat quality of livestock animal species are here reviewed. Macroalgae are classified into Phaeophyceae (brown algae), Rhodophyceae (red algae) and Chlorophyceae (green algae). The most common macroalga genera used as livestock feedstuffs are: Ascophyllum, Laminaria and Undaria for brown algae; Ulva, Codium and Cladophora for green algae; and Pyropia, Chondrus and Palmaria for red algae. Macroalgae are rich in many nutrients, including bioactive compounds, such as soluble polysaccharides, with some species being good sources of n-3 and n-6 polyunsaturated fatty acids. To date, the incorporation of macroalgae in livestock animal diets was shown to improve growth and meat quality, depending on the alga species, dietary level and animal growth stage. Generally, Ascophyllum nodosum can increase average daily gain (ADG) in ruminant and pig mostly due to its prebiotic activity in animal's gut. A. nodosum also enhances marbling score, colour uniformity and redness, and can decrease saturated fatty acids in ruminant meats. Laminaria sp., mainly Laminaria digitata, increases ADG and feed efficiency, and improves the antioxidant potential of pork. Ulva sp., and its mixture with Codium sp., was shown to improve poultry growth at up to 10% feed. Therefore, seaweeds are promising sustainable alternatives to corn and soybean as feed ingredients, thus attenuating the current competition among food-feed-biofuel industries. In addition, macroalgae can hinder eutrophication and participate in bioremediation. However, some challenges need to be overcome, such as the development of large-scale and cost-effective algae production methods and the improvement of algae digestibility by monogastric animals. The dietary inclusion of Carbohydrate-Active enZymes (CAZymes) could allow for the degradation of recalcitrant macroalga cell walls, with an increase of nutrients bioavailability. Overall, the use of macroalgae as feedstuffs is a promising strategy for the development of a more sustainable livestock production.

Benefits and Drawbacks of Ultrasound-Assisted Extraction for the Recovery of Bioactive Compounds from Marine Algae

The increase in life expectancy has led to the appearance of chronic diseases and interest in healthy aging, in turn promoting a growing interest in bioactive compounds (BCs) and functional ingredients. There are certain foods or products rich in functional ingredients, and algae are one of them. Algae consumption has been nominal in Europe until now. However, in recent years, it has grown significantly, partly due to globalization and the adoption of new food trends. With the aim of obtaining BCs from foods, multiple methods have been proposed, ranging from conventional ones, such as maceration or Soxhlet extraction, to more innovative methods, e.g., ultrasound-assisted extraction (UAE). UAE constitutes a novel method, belonging to so-called green chemistry, that enables the extraction of BCs requiring lower amounts of solvent and energy costs, preserving the integrity of such molecules. In recent years, this method has been often used for the extraction of different BCs from a wide range of algae, especially polysaccharides, such as carrageenans and alginate; pigments, including fucoxanthin, chlorophylls, or β-carotene; and phenolic compounds, among others. In this way, the application of UAE to marine algae is an efficient and sustainable strategy to pursue their deep characterization as a new source of BCs, especially suitable for vegetarian and vegan diets.

Seaweeds as Valuable Sources of Essential Fatty Acids for Human Nutrition

The overexploitation of terrestrial habitats, combined with the ever-growing demand for food, has led to the search for alternative food sources. The importance of seaweeds as food sources has been growing, and their potential as sources of fatty acids (FA) make seaweeds an interesting feedstock for the food and nutraceutical industries. The aim of this study is to assess the potential of five red seaweeds (Asparagospis armata, Calliblepharis jubata, Chondracanthus teedei var. lusitanicus, Gracilaria gracilis, and Grateloupia turuturu) and three brown seaweeds (Colpomenia peregrina, Sargassum muticum and Undaria pinnatifida), harvested in central Portugal, as effective sources of essential FA for food or as dietary supplements. FA were extracted from the biomass, transmethylated to methyl esters, and analyzed through gas chromatography-mass spectrometry. G. gracilis presented the highest content of saturated fatty acids (SFA) (41.49 mg·g-1), whereas C. jubata exhibited the highest content of highly unsaturated fatty acids (HUFA) (28.56 mg·g-1); the three G. turuturu life cycle stages presented prominent SFA and HUFA contents. Omega-6/omega-3 ratios were assessed and, in combination with PUFA+HUFA/SFA ratios, it is suggested that C. jubata and U. pinnatifida may be the algae with highest nutraceutical potential, promoting health benefits and contributing to a balanced dietary intake of fatty acids.

Bioactive Compounds in Edible Oils and Their Role in Oxidative Stress and Inflammation

Diet and inflammatory response are recognized as strictly related, and interest in exploring the potential of edible fats and oils for health and chronic diseases is emerging worldwide. Polyunsaturated fatty acids (PUFAs) present in fish oil (FO), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), may be partly converted into oxygenated bioactive lipids with anti-inflammatory and/or pro-resolving activities. Moreover, the co-presence of phenolic compounds and vitamins in edible oils may prevent the development of chronic diseases by their anti-inflammatory, antioxidant, neuroprotective, and immunomodulatory activities. Finally, a high content in mono-unsaturated fatty acids may improve the serum lipid profile and decrease the alterations caused by the oxidized low-density lipoproteins and free radicals. The present review aims to highlight the role of lipids and other bioactive compounds contained in edible oils on oxidative stress and inflammation, focusing on critical and controversial issues that recently emerged, and pointing to the opposing role often played by edible oils components and their oxidized metabolites.

Whole Alga, Algal Extracts, and Compounds as Ingredients of Functional Foods: Composition and Action Mechanism Relationships in the Prevention and Treatment of Type-2 Diabetes Mellitus

Type-2 diabetes mellitus (T2DM) is a major systemic disease which involves impaired pancreatic function and currently affects half a billion people worldwide. Diet is considered the cornerstone to reduce incidence and prevalence of this disease. Algae contains fiber, polyphenols, ω-3 PUFAs, and bioactive molecules with potential antidiabetic activity. This review delves into the applications of algae and their components in T2DM, as well as to ascertain the mechanism involved (e.g., glucose absorption, lipids metabolism, antioxidant properties, etc.). PubMed, and Google Scholar databases were used. Papers in which whole alga, algal extracts, or their isolated compounds were studied in in vitro conditions, T2DM experimental models, and humans were selected and discussed. This review also focuses on meat matrices or protein concentrate-based products in which different types of alga were included, aimed to modulate carbohydrate digestion and absorption, blood glucose, gastrointestinal neurohormones secretion, glycosylation products, and insulin resistance. As microbiota dysbiosis in T2DM and metabolic alterations in different organs are related, the review also delves on the effects of several bioactive algal compounds on the colon/microbiota-liver-pancreas-brain axis. As the responses to therapeutic diets vary dramatically among individuals due to genetic components, it seems a priority to identify major gene polymorphisms affecting potential positive effects of algal compounds on T2DM treatment.

Proteins extracted from seaweed Undaria pinnatifida and their potential uses as foods and nutraceuticals

Isolation and utilization of proteins from seaweeds have been a novel trend in the world at present due to the increasing demand for healthy non-animal proteins. The attention of scientific community has been paid on the protein derived from seaweed Undaria pinnatifida due to their high nutritional quality and bioactivity. This article aims to provide an integrated overview on methods of extraction, isolation and purification of U. pinnatifida-derived proteins and composition, nutritional value and potential nutraceutical and food applications with an interest to stimulate further research to optimize the utilization. Potential food applications of U. pinnatifida derived proteins are nutritional components in human diet, food ingredients and additives, alternative meat and meat analogues and animal and fish feed. Excellent antioxidant, antihypertension, anticoagulant, anti-diabetes, antimicrobial and anti-cancer activities possessed by proteins of U. pinnatifida enable the use of these proteins in various nutraceutical applications. A number of studies have been carried out on antioxidant and antihypertensive activities of U. pinnatifida proteins, whereas other bioactivites are yet to be further studied. Hence, more research works are crucial to be done in order to facilitate and promote the emerging novel foods and nutraceuticals, using proteins from seaweed U. pinnatifida.

The dual effects of riboflavin and kelp polyphenol extracts on the gel properties of myofibrillar protein from Scomberomorus Niphonius under UVA irradiation

In the present study, effects of riboflavin (RF) and kelp polyphenol extracts (KPE) on mackerel (Scomberomorus Niphonius) myofibrillar protein (MP) gel were studied with or without ultraviolet A (UVA) irradiation treatment. The gel strength was increased with the addition of RF and KPE under UVA irradiation. Analysis of the proteins in the gel indicated that the carbonyl content increased, while the contents of total sulfhydryl and amino groups decreased. The proteins appeared to have no α-helix structures, and the endogenous tryptophan content appeared to decrease. The results of SDS-PAGE indicated that the RF and KPE treated samples under UVA irradiation showed massive MP cross-linking by covalent bonds. Electron spin resonance (ESR) results indicated that UVA irradiation generated free radicals in RF and KPE, which ultimately led to an improvement in MP gel properties. It also indicated that KPE could prevent the occurrence of peroxidation to improve the gel properties.

Bioprospecting Cultivated Tropical Green Algae, Caulerpa racemosa (Forsskal) J. Agardh: A Perspective on Nutritional Properties, Antioxidative Capacity and Anti-Diabetic Potential

Caulerpa racemosa (Forsskal) J. Agardh is a green seaweed used as food and folk medicine since ancient times in the Indo-Pacific region, particularly in southeast Asia. In this study, the proximate nutrient composition, phytochemical, anti-oxidant and anti-diabetic properties of sea grape C. racemosa collected from culture fishponds in Johor, Malaysia were analysed. The contents (dry weight basis) of carbohydrate, crude protein, crude lipids, ash and caloric value obtained were 33.42 ± 1.34%, 20.27 ± 0.14%, 4.20 ± 0.32%, 28.25 ± 0.27% and 2544.67 ± 7.04 cal g-1, respectively. The amino acid score (AAs) and biological protein value (213.43 mg g-1) indicated that C. racemosa presented a better protein quality. The most abundant fatty acids were C16:0 (palmitic acid: 63.27%), followed by C18:1 (oleic acid: 5.80%), and C18:2 ῳ6 (linoleic acid: 5.33%). The analysis of the ash content indicated that essential minerals and trace elements, such as Ca, Fe, and Mn, were present in the seaweed. The total phenolic content (TPC) and total flavonoid content (TFC) observed in the ethyl acetate extract were 17.88 ± 0.78 mg GAE g-1 and 59.43 ± 2.45 mg QE g-1, respectively. The ethyl acetate extract of C. racemosa demonstrated notable anti-diabetic activity in diabetic induced rats. The low (100 mg kg-1) and high (200 mg kg-1) doses of cultivated C. racemosa extract exhibited a significant decrease (p < 0.05) in blood glucose levels while preventing weight loss, reducing plasma AST, ALT levels as a sign of hepatoprotective effect and recording albumin levels similar to positive control in diabetic induced rats. The results support the usefulness of cultivated C. racemosa as a potential functional food.

Proximal Composition of Undaria pinnatifida from San Jorge Gulf (Patagonia, Argentina)

Undaria pinnatifida is a brown macroalga considered a high quality natural food because of its numerous health benefits. The aim of this paper is to provide seasonal information on the chemical content of blades and sporophylls of U. pinnatifida from San Jorge Gulf (SJG, Chubut, Argentina) in order to evaluate their different uses. Moreover, samples of algae deposited on the beach are also studied. A multi-elemental analysis is made by Total Reflection X-ray Fluorescence (TXRF). Sixteen elements are quantified: As, Br, Ca, Cr, Cu, Fe, K, Mn, Ni, P, Pb, Rb, S, Sr, V and Zn. The results reveal that the mineral content in blades of U. pinnatifida is high, especially in autumn. Some elements show an important seasonal variation, such as: K (14-54.8 g kg-1), P (2.7-7.0 g kg-1), Sr (361-569 mg kg-1), Fe (62-140 mg kg-1), Zn (8-103 mg kg-1), Br (45-94 mg kg-1) and Rb (4-24 mg kg-1). In the case of potentially toxic elements, a variation was seen mainly in arsenic, with higher values during summer and autumn. The concentrations of nickel and lead are below the limit of detection (0.9 mg kg-1). Sporophylls contain high concentrations of macro and micronutrients, with maximum values in spring. Besides, reproductive structures showed higher total arsenic values than blades. This could indicate that arsenic is mainly accumulated in sporophylls. Algae deposited on the beach are considered a waste; but they show a similar elemental composition to the samples extracted from the sea. We concluded that all samples analyzed could be used as food or fertilizers by local populations.

Immunostimulatory and antioxidant effects of supplemental feeding with macroalga Sargassum spp. on goat kids

Algae are a rich source of bioactive compounds and health properties that have been narrowly explored in goat production systems. The aim of this study was to determine the effect of feeding diets supplemented with Sargassum spp. on antioxidant status and immune parameters in goat kids. The diets were as follows: control (basal diet without alga), Sargassum spp. 2.5% (Ss2.5), and Sargassum spp. 5% (S5) fed over a 70-day period. A total of 11 body tissues, intestinal mucus, and blood serum were sampled at necropsy. Protein content, superoxide dismutase (SOD), catalase (CAT), myeloperoxidase (MPO), lysozyme, and anti-protease activities were determined, as well as immunoglobulin A (IgA) and immunoglobulin G (IgG). The results indicated that Sargassum spp. supplementation increased protein content in six tissues. Antioxidant activities (SOD and CAT) and immune-related (lysozyme, MPO, and anti-protease) activities were statistically higher (P < 0.05) in Sargassum spp. groups compared with control in several tissues, intestinal mucus, and serum. Imunoglobulin A levels in intestinal mucus were higher (P < 0.05) in Sargassum spp.-supplemented groups than the control group. In conclusion, diet supplementation of Sargassum spp. improves the antioxidant status and enhances the immune parameters in goats. Sargassum spp. dietary supplementation is proposed as strategy to strengthen antioxidant status and stimulate the immune system, which helps in the control of opportunistic pathogens in goats.

Seaweeds as a Functional Ingredient for a Healthy Diet

Seaweeds have been used since ancient times as food, mainly by Asian countries, while in Western countries, their main application has been as gelling agents and colloids for the food, pharmaceuticals, and the cosmetic industry. Seaweeds are a good source of nutrients such as proteins, vitamins, minerals, and dietary fiber. Polyphenols, polysaccharides, and sterols, as well as other bioactive molecules, are mainly responsible for the healthy properties associated with seaweed. Antioxidant, anti-inflammatory, anti-cancer, and anti-diabetic properties are attributed to these compounds. If seaweeds are compared to terrestrial plants, they have a higher proportion of essential fatty acids as eicosapentaenoic (EPA) and docosahexaenoic (DHA) fatty acids. In addition, there are several secondary metabolites that are synthesized by algae such as terpenoids, oxylipins, phlorotannins, volatile hydrocarbons, and products of mixed biogenetic origin. Therefore, algae can be considered as a natural source of great interest, since they contain compounds with numerous biological activities and can be used as a functional ingredient in many technological applications to obtain functional foods.

Dietary Supplementation with the Red Seaweed Porphyra umbilicalis Protects against DNA Damage and Pre-Malignant Dysplastic Skin Lesions in HPV-Transgenic Mice

Some diet profiles are associated with the risk of developing cancer; however, some nutrients show protective effects. Porphyra umbilicalis is widely consumed, having a balanced nutritional profile; however, its potential for cancer chemoprevention still needs comprehensive studies. In this study, we incorporated P. umbilicalis into the diet of mice transgenic for the human papillomavirus type 16 (HPV16), which spontaneously develop pre-malignant and malignant lesions, and determined whether this seaweed was able to block lesion development. Forty-four 20-week-old HPV^+/− and HPV^−/− mice were fed either a base diet or a diet supplemented with 10% seaweed. At the end of the study, skin samples were examined to classify HPV16-induced lesions. The liver was also screened for potential toxic effects of the seaweed. Blood was used to study toxicological parameters and to perform comet and micronucleus genotoxicity tests. P. umbilicalis significantly reduced the incidence of pre-malignant dysplastic lesions, completely abrogating them in the chest skin. These results suggest that P. umbilicalis dietary supplementation has the potential to block the development of pre-malignant skin lesions and indicate its antigenotoxic activity against HPV-induced DNA damage. Further studies are needed to establish the seaweed as a functional food and clarify the mechanisms whereby this seaweed blocks multistep carcinogenesis induced by HPV.

Effects of Seasonal Variability on the Physicochemical, Biochemical, and Nutritional Composition of Western Peninsular Malaysia Gracilaria manilaensis

This study evaluated the effect of seasonal variation on the physicochemical, biochemical, and nutritional composition of Gracilaria manilaensis. Sampling was designed during the main monsoon seasons in Malaysia-the Southwest monsoon (SWM) and Northeast monsoon (NEM)-to understand the intraspecific variation (p < 0.05). Carbohydrates, protein, and dietary fiber were found to be higher in NEM-G. manilaensis, whereas a higher ash content was quantified in SWM-G. manilaensis. No significant differences were found in crude lipid and moisture content (p > 0.05). Vitamin B2 was calculated as (0.29 ± 0.06 mg 100 g^-1) and (0.38 ± 0.06 mg 100 g^-1) for the NEM and SWM samples, respectively (p < 0.05). The fatty acid profile showed the dominance of saturated fatty acids (SFAs)-palmitic acids, stearic acid, and myristic acid-while the mineral contents were found to be good sources of calcium (1750.97-4047.74 mg 100 g^-1) and iron (1512.55-1346.05 mg 100 g^-1). Tryptophan and lysine were recorded as the limiting essential amino acids (EAAs) in NEM G. manilaensis, while leucine and phenylalanine were found to be the limiting EAAs in the SWM samples. None of the extracts exhibited antibacterial properties against the screened strains. The study concluded that seasonal changes have a great effect on the biochemical composition of G. manilaensis.

A Two-Week Treatment with Plant Extracts Changes Gut Microbiota, Caecum Metabolome, and Markers of Lipid Metabolism in ob/ob Mice

SCOPE

Targeting gut microbiota dysbiosis by prebiotics is effective, though side effects such as abdominal bloating and flatulence may arise following high prebiotic consumption over weeks. The aim is therefore to optimize the current protocol for prebiotic use.

METHODS AND RESULTS

To examine the prebiotic properties of plant extracts, two independent studies are conducted in ob/ob mice, over two weeks. In the first study, Porphyra umbilicalis and Melissa officinalis L. extracts are evaluated; in the second study, a high vs low dose of an Emblica officinalis Gaertn extract is assessed. These plant extracts affect gut microbiota, caecum metabolome, and induce a significant lower plasma triacylglycerols (TG) following treatment with P. umbilicalis and significantly higher plasma free fatty acids (FFA) following treatment with the low-dose of E. officinalis Gaertn. Glucose- and insulin-tolerance are not affected but white adipose tissue and liver gene expression are modified. In the first study, IL-6 hepatic gene expression is significantly (adjusted p = 0.0015) and positively (r = 0.80) correlated with the bacterial order Clostridiales in all mice.

CONCLUSION

The data show that a two-week treatment with plant extracts affects the dysbiotic gut microbiota and changes both caecum metabolome and markers of lipid metabolism in ob/ob mice.

Immunomodulatory and Antioxidant Activities of Sulfated Polysaccharides from Laminaria ochroleuca, Porphyra umbilicalis, and Gelidium corneum

Seaweeds of the genera Laminaria, Gelidium, and Porphyra have been used in both food and non-food industries due to their unique properties and characteristic biological activity. This study assesses the antioxidant activity and immunomodulatory properties of the acidic polysaccharides extracted from Laminaria ochroleuca, Porphyra umbilicalis, and Gelidium corneum collected in the Atlantic coast of Tarifa (Cadiz, Spain). The proliferation of murine cell line RAW 264 decreased with increasing concentration of polysaccharides of the three algal species. The highest both antioxidant (25.69 μmol TE g-1 DW) and immunomodulatory activities were observed in the sulfated polysaccharides of L. ochroleuca compared to that of P. umbilicalis and G. corneum. Sulfated polysaccharides of L. ochroleuca presented high potential anticancer activity in cell lines of human colon cancer HTC-116 (IC50 = 0.44 mg mL-1), human malignant melanoma G-361 (IC50 = 5.42 mg mL-1), breast adenocarcinoma human MCF-7 (IC50 = 8.32 mg mL-1), and human leukemia U-937 (IC50 = 3.72 mg mL-1). It is concluded that metabolites of L. ochroleuca can offer significant advantages for the pharmaceutical industry, particularly when macrophage activation is required.

Risks and benefits of consuming edible seaweeds

Recent interest in seaweeds as a source of macronutrients, micronutrients, and bioactive components has highlighted prospective applications within the functional food and nutraceutical industries, with impetus toward the alleviation of risk factors associated with noncommunicable diseases such as obesity, type 2 diabetes, and cardiovascular disease. This narrative review summarizes the nutritional composition of edible seaweeds; evaluates the evidence regarding the health benefits of whole seaweeds, extracted bioactive components, and seaweed-based food products in humans; and assesses the potential adverse effects of edible seaweeds, including those related to ingestion of excess iodine and arsenic. If the potential functional food and nutraceutical applications of seaweeds are to be realized, more evidence from human intervention studies is needed to evaluate the nutritional benefits of seaweeds and the efficacy of their purported bioactive components. Mechanistic evidence, in particular, is imperative to substantiate health claims.

Recovery of bioactive and gelling extracts from edible brown seaweed Laminaria ochroleuca by non-isothermal autohydrolysis

The non-isothermal autohydrolysis temperature impact of edible brown seaweed Laminaria ochroleuca was studied to recover high valuable compounds. Extraction yield was determined, above 80% was obtained at 220 °C. The maximal fucose content (17% d.b.) was attained at 180 °C, whereas the maximal sulphate was achieved at 160 °C, and phenolic and protein content at 220 °C. The maximum sulphated fucoidan content (41.38 g fucoidan/100 g extract) was obtained at 160 °C, whereas the maximum fucose oligosaccharides was obtained at 180 °C. The antioxidant capacity was equivalent to 32 mg Trolox/g dry extract produced at 220 °C. The milder processing condition was selected to study the potentiality of the precipitated alginate in terms of viscoelastic properties determined by rheology. Alginate extraction (14.94 g/100 g extract) was determined at 160 °C. The crude fucoidan fractions were tested at 25-500 μg/mL, showed up to 50% cell growth inhibition in four selected tumoral cell lines.

Health Benefits and Pharmacological Effects of Porphyra Species

Porphyra, one of the most cultured red algae has gained economic importance across the globe for its nutritional benefits. Porphyra is being cultivated, harvested, dried, processed and consumed in large quantities in south eastern countries. It contains relatively high amounts of proteins, carbohydrates, and micronutrients. Exploitation of its fundamental attributes led to the discovery of various biologically active compounds like polysaccharides, phycobiliproteins and peptides with effective pharmacological applications. In this review, a systematic account of the research accomplished in the past decade and up-to-date overview of various bioactive compounds and its pharmacological implications has been compiled. This review summarizes the bioactivities like antioxidative, immunomodulatory, antihypertensive, anticoagulant and anticancer properties of the bioactive compounds from Porphyra.

Proximate Composition and Nutritional Value of Three Macroalgae: Ascophyllum nodosum, Fucus vesiculosus and Bifurcaria bifurcata

Proximate composition (moisture, protein, lipid and ash content) and nutritional value (fatty acid, amino acid and mineral profile) of three macroalgae (Ascophyllum nodosum, Fucus vesiculosus and Bifurcaria bifurcate) were studied. Chemical composition was significantly (p < 0.001) different among the three seaweeds. In this regard, the B. bifurcata presented the highest fat content (6.54% of dry matter); whereas, F. vesiculosus showed the highest protein level (12.99% dry matter). Regarding fatty acid content, the polyunsaturated fatty acids (PUFAs) were the most abundant followed by saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs). On the other hand, the three seaweeds are a rich source of K (from 3781.35 to 9316.28 mg/100 g), Mn (from 8.28 to 1.96 mg/100 g), Na (from 1836.82 to 4575.71 mg/100 g) and Ca (from 984.73 to 1160.27 mg/100 g). Finally, the most abundant amino acid was glutamic acid (1874.47-1504.53 mg/100 dry matter), followed by aspartic acid (1677.01-800.84 mg/100 g dry matter) and alanine (985.40-655.73 mg/100 g dry matter).

Assessment of the functional properties of protein extracted from the brown seaweed Himanthalia elongata (Linnaeus) S. F. Gray

A protein extract from the brown seaweed Himanthalia elongata (Linnaeus) S. F. Gray was prepared and its functional properties, colour and amino acid composition were assessed for its potential future use by the food industry. The total content of amino acids was determined as 54.02±0.46gaminoacids/kg dry weight, with high levels of the essential amino acids lysine and methionine. SDS-PAGE showed 5 protein bands with molecular weights of 71.6, 53.7, 43.3, 36.4 and 27.1kDa. The water holding capacity and oil holding capacity were determined as 10.27±0.09gH2O/g and 8.1±0.07goil/g respectively. Foaming activity and stability were higher at alkaline pH values. The emulsifying capacity and stability of the extract varied depending on the pH and oil used. These results demonstrate the potential use of Himanthalia elongata protein extract in the food industry.

A comprehensive approach to formulation of seaweed-enriched meat products: From technological development to assessment of healthy properties

Meat consumption is influenced by various kinds of factors, among them health implications. Different strategies can be effective in developing meat-based functional foods. These basically entail reducing the presence of compounds with negative health implications and enhancing the presence of beneficial compounds. This article reviews a comprehensive model for the development of meat-based functional foods based on a presentation of the research achieved in terms of the design and development of qualitatively and quantitatively modified meat products (frankfurters, patties and restructured steaks). These were reformulated to incorporate nutrients associated with three different seaweeds (wakame-Undaria pinnatifida; nori-Porphyra umbilicalis; and sea spaghetti-Himanthalia elongata) as sources of bioactive substances, while simultaneously reducing sodium and fat and improving fatty acid profiles. Those seaweeds were chosen, because in terms of composition and health implications, abundance on Spanish coasts, relatively widespread consumption, and suitability in terms of flavour and colour they are better suited than others for use as ingredients in new products. It also discusses the consequences of the use of this type of meat-based functional foods (combination of pork meat and 5% of each seaweed with or without hypercholesterolaemic agent included in the diets) on growing animals (Wistar male rats), and their effects on different aspects of lipoprotein metabolism, oxidative stress and liver structure. This article, then, reports a comprehensive approach to the production of seaweed-enriched meat products, considering aspects of technological development aimed at achieving the functional effect.