An examination of the potential of seaweed extracts as functional ingredients in milk

Novel Therapeutic Approach for Obesity: Seaweeds as an Alternative Medicine with the Latest Conventional Therapy

The prevalence of overweight and obesity is increasing worldwide. Common comorbidities related to obesity, significantly polygenic disorders, cardiovascular disease, and heart conditions affect social and monetary systems. Over the past decade, research in drug discovery and development has opened new paths for alternative and conventional medicine. With a deeper comprehension of its underlying mechanisms, obesity is now recognized more as a chronic condition rather than merely a result of lifestyle choices. Nonetheless, addressing it solely through lifestyle changes is challenging due to the intricate nature of energy regulation dysfunction. The Federal Drug Administration (FDA) has approved six medications for the management of overweight and obesity. Seaweed are plants and algae that grow in oceans, rivers, and lakes. Studies have shown that seaweed has therapeutic potential in the management of body weight and obesity. Seaweed compounds such as carotenoids, xanthophyll, astaxanthin, fucoidans, and fucoxanthin have been demonstrated as potential bioactive components in the treatment of obesity. The abundance of natural seaweed bioactive compounds has been explored for their therapeutic potential for treating obesity worldwide. Keeping this view, this review covered the latest developments in the discovery of varied anti-obese seaweed and its bioactive components for the management of obesity.

Evaluation of Antibiofilm and Antiquorum Sensing Activities of Fucoidan Characterized from Padina boryana against Nosocomial Pathogens

Modern functional chemicals that can be employed in biotechnology, pharmaceutics, and food science are a sustainable source to be found in seaweeds. The bioactivity of the majority of these marine compounds has received scant research. Fucoidan is a highly sulfated polysaccharide with a range of bioactivities, including an antipathogenic effect. There is still much to learn about the relationship between fucoidan structure and its function in pathogen infections. By employing microwave and probe sonication to create crude fucoidan, DEAE-cellulose anion-exchange chromatography was used to further purify the substance. Purified fucoidan was structurally characterized using UV-Visible spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and NMR analysis. The results of the structural analysis demonstrate that sulfates and hydroxyl groups are present in the isolated fucoidan. There are fucose residues, according to the NMR data. The present study investigates the bioactivity of fucoidan, a polysaccharide derived from the brown algae Padina boryana, as a potent weapon against the known nosocomial diseases Proteus vulgaris and Salmonella enterica. Fluorescence microscopy was used to show that fucoidan antibiofilm action is totally effective against Proteus vulgaris and Salmonella enterica biofilm formations as well as planktonic cell growths at dosages over 25 g/mL. Here, using in vitro investigations of the possible inactivation of molecules that are regulated by acyl-homoserine lactone (AHL) in both bacterial species, we explore the antiquarum sensing and antibiofilm capabilities of fucoidan. According to the present study, extracted fucoidan from Padina boryana can be used to generate antibacterial compounds and operate as a quorum-sensing inhibitor to combat side effects and antibiotic resistance.

Macroalgae-derived bioactive compounds for functional food and pharmaceutical applications-a critical review

The rising demand for global food resources, combined with an overreliance on land-based agroecosystems, poses a significant challenge for the sustainable production of food products. Macroalgae cultivation is a promising approach to mitigate impending global food insecurities due to several key factors: independence from terrestrial farming, rapid growth rates, unique biochemical makeup, and carbon capture potential. Furthermore, macroalgae are rich in vitamins, minerals, essential amino acids, polyunsaturated fatty acids and fiber, demonstrating significant potential as sustainable alternatives for enhancing dietary diversity and fulfilling nutritional requirements. This review provides an overview of the nutritional composition and functional properties of commercially cultivated macroalgae species, with emphasis on their viability as value additions to the functional food market. Furthermore, the review discusses the technological aspects of integrating macroalgae into food products, covering both innovative solutions and existing challenges. Macroalgae, beyond being nutritional powerhouses, contain a plethora of bioactive compounds with varied biological activities, including anti-diabetic, anti-cancer, cardioprotective, and neuroprotective properties, making them excellent candidates in developing novel pharmaceuticals. Thus, this review also summarizes the pharmaceutical applications of macroalgae, identifies research gaps and proposes potential strategies for incorporating macroalgae-derived bioactive compounds into therapeutic products.

Tropical Seaweeds as a Sustainable Resource Towards Circular Bioeconomy: Insights and Way Forward

Seaweeds are photosynthetic marine macroalgae known for their rapid biomass growth and their significant contributions to global food and feed production. Seaweeds play a crucial role in mitigating various environmental issues, including greenhouse gases, ocean acidification, hypoxia, and eutrophication. Tropical seaweeds are typically found in tropical and subtropical coastal zones with warmer water temperatures and abundant sunlight. These tropical seaweeds are rich sources of proteins, vitamins, minerals, fibers, polysaccharides, and bioactive compounds, contributing to their health-promoting properties and their diverse applications across a range of industries. The productivity, cultivability, nutritional quality, and edibility of tropical seaweeds have been well-documented. This review article begins with an introduction to the growth conditions of selected tropical seaweeds. Subsequently, the multifunctional properties of tropical seaweeds including antioxidant and anti-inflammatory, anti-coagulant, anti-carcinogenic and anti-proliferative, anti-viral, therapeutic and preventive properties were comprehensively evaluated. The potential application of tropical seaweeds as functional foods and feeds, as well as their contributions to sustainable cosmetics, bioenergy, and biofertilizer production were also highlighted. This review serves as a valuable resource for researchers involved in seaweed farming as it provides current knowledge and insights into the cultivation and utilization of seaweeds.

On the Valorization of Arbutus unedo L. Pomace: Polyphenol Extraction and Development of Novel Functional Cookies

The fruits of Arbutus unedo L. have a crimson colour and are enriched with remarkable concentrations of bioactive compounds such as anthocyanins and polyphenols. These fruits are commonly used in the production of a Portuguese Protected Geographical Indication distillate called "Aguardente de Medronho". During this process, a solid pomace is generated and presently discarded without valuable applications. In this work, two strategies have been developed for the valorisation of A. unedo pomace. The first approach considers the extraction of polyphenols from this by-product through the optimization of an ultrasound-assisted method using a Box-Behnken design coupled with response surface methodology. The results indicate that the temperature and the percentage of methanol, along with their interaction, significantly influence the total concentration of polyphenols and the antioxidant activity of the extracts obtained. The optimal conditions identified consider the extraction of 0.5 g of sample with 20 mL of a solvent containing 74% MeOH (aq), at a pH of 4.8, maintained at 70 °C for 15 min. On the other hand, the second valorisation strategy considered the use of A. unedo pomace in the development of functional cookies. The incorporation of 15-20% pomace in the cookie formulation was well-received by consumers. This incorporation results in an intake of ca. 6.55 mg of polyphenols per gram of cookie consumed, accompanied by an antioxidant activity of 4.54 mg Trolox equivalents per gram of cookie consumed. Overall, these results encourage the employment of A. unedo pomace either as a reliable source of extracts enriched in polyphenols or as a nutraceutical active ingredient in functional cookies, thereby positively impacting human health.

Phlorotannins: Novel Orally Administrated Bioactive Compounds That Induce Mitochondrial Dysfunction and Oxidative Stress in Cancer

Mitochondrial dysfunction is an interesting therapeutic target to help reduce cancer deaths, and the use of bioactive compounds has emerged as a novel and safe approach to solve this problem. Here, we discuss the information available related to phlorotannins, a type of polyphenol present in brown seaweeds that reportedly functions as antioxidants/pro-oxidants and anti-inflammatory and anti-tumorigenic agents. Specifically, available evidence indicates that dieckol and phloroglucinol promote mitochondrial membrane depolarization and mitochondria-dependent apoptosis. Phlorotannins also reduce pro-tumorigenic, -inflammatory, and -angiogenic signaling mechanisms involving RAS/MAPK/ERK, PI3K/Akt/mTOR, NF-κB, and VEGF. In doing so, they inhibit pathways that favor cancer development and progression. Unfortunately, these compounds are rather labile and, therefore, this review also summarizes approaches permitting the encapsulation of bioactive compounds, like phlorotannins, and their subsequent oral administration as novel and non-invasive therapeutic alternatives for cancer treatment.

Brown algae and their multiple applications as functional ingredient in food production

Brown algae are considered one of the resources that can contribute to transforming our global food system by promoting healthier diets and reducing environmental impact. In this sense, this review article aims to provide up-to-date information on the nutritional and functional improvement of brown algae when they are applied to different food matrices. Brown algae present sulfated polysaccharides (alginates, fucoidans, and laminarins), proteins, minerals, vitamins, dietary fibers, fatty acids, pigments, and bioactive compounds that can positively contribute to the development of highly nutritious food products, as well as used reformulate products already existing, to remove, reduce, increase, add and/or replace different components and obtain products that confer health-promoting properties. This review demonstrates that there is a tendency to use seaweed for the production of functional foods and that the number of commercially produced products from seaweed is increasing, that is, seaweed is a sector whose global market is expanding.

Biomolecules from Macroalgae-Nutritional Profile and Bioactives for Novel Food Product Development

Seaweed is in the spotlight as a promising source of nutrition for humans as the search for sustainable food production systems continues. Seaweed has a well-documented rich nutritional profile containing compounds such as polyphenols, carotenoids and polysaccharides as well as proteins, fatty acids and minerals. Seaweed processing for the extraction of functional ingredients such as alginate, agar, and carrageenan is well-established. Novel pretreatments such as ultrasound assisted extraction or high-pressure processing can be incorporated to more efficiently extract these targeted ingredients. The scope of products that can be created using seaweed are wide ranging: from bread and noodles to yoghurt and milk and even as an ingredient to enhance the nutritional profile and stability of meat products. There are opportunities for food producers in this area to develop novel food products using seaweed. This review paper discusses the unique properties of seaweed as a food, the processes involved in seaweed aquaculture, and the products that can be developed from this marine biomass. Challenges facing the industry such as consumer hesitation around seaweed products, the safety of seaweed, and processing hurdles will also be discussed.

Preparation of Bioactive De-Chlorophyll Rhein-Rich Senna alata Extract

Senna alata leaves display various biological activities as a result of their rhein and phenolic composition. The objective of this study was to develop bioactive de-chlorophyll rhein-rich S. alata extracts. The rhein content was quantified using a validated high-performance liquid chromatography-diode array detection (HPLC-DAD) method. The best process parameters for maximizing rhein were established using ultrasound-assisted extraction (UAE). The optimal conditions for the parameters were determined using the Box-Behnken design (BBD); 95% v/v ethanol was used as the extraction solvent at 59.52 °C for 18.4 min with a solvent-to-solid ratio of 25.48:1 (mL/g) to obtain the predicted value of rhein at 10.44 mg/g extract. However, the color of the rhein-rich extract remained dark brown. For the removal of chlorophyll, liquid-liquid extraction with vegetable oils and adsorption with bleaching agents were employed. The bleaching agents were significantly more effective at removing chlorophyll and had less of an effect on the reduction in rhein content than vegetable oils. The presence of rhein and phenolics in the de-chlorophyll extracts might be responsible for their antioxidant, anti-inflammatory, and antibacterial activities. These findings indicate that rhein-rich extract and its de-chlorophyll extracts possess sufficient biological activities for the further development of cosmeceuticals and pharmaceuticals.

Brown Algae Fucus vesiculosus in Pasta: Effects on Textural Quality, Cooking Properties, and Sensorial Traits

Fucus vesiculosus is a brown seaweed rich in iodine, fucoxanthin, and phlorotannins, all known to be bioactive compounds associated with health-promoting events. The enrichment of a staple food such as pasta with seaweed flour, could convey health benefits without changing eating habits. In this work, F. vesiculosus flour (FVF) was incorporated into durum wheat pasta at 1, 5.5, and 10% gradient levels. The pasta enriched with FVF needed additional water during dough formation and required more cooking time, resulting in higher weight gain but also increased cooking loss (observed with 5.5 and 10%). The fracturability of raw pasta decreased for all the FVF pasta, though the cooked firmness and hardness were only affected with the inclusion of 10% FVF. The substitution of wheat semolina with FVF at a 10% level caused an increase in the pasta’s fiber content, which resulted in a more discontinuous protein–matrix structure, as observed at the microscopic level. Untrained consumers were very positive about the overall sensory traits of the pasta with low supplementation levels (1 and 5.5%). About 72% of panelists selected the 1% FVF pasta as their favorite sample. The utilization of FVF in pasta should be targeted at low inclusion levels to cope with the expected texture quality and prevent the impairment of the sensory traits.

The possible role of the seaweed Sargassum vulgare as a promising functional food ingredient minimizing aspartame-associated toxicity in rats

Thirty-two male Wistar albino rats were chosen to test the possible protective role of antioxidants of the edible seaweed Sargassum vulgare as a functional food additive to alleviate oxidative stress and toxicity associated with consumption of the artificial sweetener 'aspartame (ASP)'. Biochemical and spleen histopathological analyses of the orally ASP-administrated rats, at a dose of 500 mg/kg for one week daily, showed different apoptotic and inflammatory patterns. Rats treated with ASP and then supplemented orally with the S. vulgare-MeOH extract, at a dose of 150 mg/kg for three consecutive weeks daily, showed significant positive reactions in all investigated assays related to ASP consumption. The protective and immune-stimulant efficacy of S. vulgare-MeOH extract, inferred from combating oxidative stress-induced lipid peroxidation, modulating the low levels of the endogenous antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) and of the thyroid hormones T3 and T4, attenuating the elevated levels of apoptotic CASP-3 and inflammatory biomarkers TNF-α and IL-6, as well as heat shock proteins (Hsp70), can be most likely ascribed to the synergistic effect of its potent antioxidant phenolics (mainly gallic, ferulic, salicylic, and chlorogenic, and p-coumaric acids) and flavonoids (rutin, kaempferol, and hesperidin). Mechanism of action of these natural antioxidants was discussed.

Macroalgal Proteins: A Review

Population growth is the driving change in the search for new, alternative sources of protein. Macroalgae (otherwise known as seaweeds) do not compete with other food sources for space and resources as they can be sustainably cultivated without the need for arable land. Macroalgae are significantly rich in protein and amino acid content compared to other plant-derived proteins. Herein, physical and chemical protein extraction methods as well as novel techniques including enzyme hydrolysis, microwave-assisted extraction and ultrasound sonication are discussed as strategies for protein extraction with this resource. The generation of high-value, economically important ingredients such as bioactive peptides is explored as well as the application of macroalgal proteins in human foods and animal feed. These bioactive peptides that have been shown to inhibit enzymes such as renin, angiotensin-I-converting enzyme (ACE-1), cyclooxygenases (COX), α-amylase and α-glucosidase associated with hypertensive, diabetic, and inflammation-related activities are explored. This paper discusses the significant uses of seaweeds, which range from utilising their anthelmintic and anti-methane properties in feed additives, to food techno-functional ingredients in the formulation of human foods such as ice creams, to utilising their health beneficial ingredients to reduce high blood pressure and prevent inflammation. This information was collated following a review of 206 publications on the use of seaweeds as foods and feeds and processing methods to extract seaweed proteins.

Effects of Sargassum virgatum extracts on the testicular measurements, genomic DNA and antioxidant enzymes in irradiated rats

BACKGROUND

Oxidative stress and reactive oxygen species (ROS) are primarily responsible for the development of male infertility after exposure to γ-irradiation. The present work aimed to assess the ameliorative and therapeutic roles of the aqueous and ethanolic extracts of the edible seaweed Sargassum virgatum (S. virgatum) on spermatogenesis and infertility in γ-irradiated Wistar rats.

MATERIALS AND METHODS

Induction of infertility was performed by exposing the rats to 137Cs-gamma rays, using a single dose of 3.5 Gy. γ-irradiated rats were given the S. virgatum ethanolic (S. virgatum-EtOH) and aqueous extracts intraperitoneally on a daily base for two consecutive weeks at doses of 100 and 400 mg/kg body weight (b.wt.) for each seaweed extract. Morphometric data of the testes, semen quality indices, antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and glutathione peroxidase (GPx), and deoxyribonucleic acid (DNA) fragmentation were assessed. The results obtained were taken during two-time intervals of 15 and 60 days from the commencement of the algal treatments. In vitro antioxidant assays and polyphenolic compounds of S. virgatum were characterized.

RESULTS

Significant negative changes in the semen quality and morphometric data of the testes, as well as remarkable DNA fragmentation, were detected in the irradiated rats compared to the control. The levels of the endogenous antioxidant enzymes (SOD, CAT, GSH, and GPx) were also significantly diminished. Nonetheless, treatments of γ-irradiated rats with the S. virgatum-EtOH and aqueous extracts significantly improved the above-mentioned enzymes, in addition to noteworthy amendments in the dimensions of the testes, the semen quality, as well as the DNA structure.

CONCLUSIONS

The ameliorative potency of S. virgatum to cure γ-irradiation-induced male infertility, particularly 400 mg/kg ethanolic extract for 60 days, is the result of the consistent therapeutic interventions of its potent antioxidant and anti-apoptotic polyphenols, particularly protocatechuic, p-hydroxybenzoic, rosmarinic, chlorogenic, cinnamic and gentisic acids, as well as the flavonoids catechin, hesperidin, rutin and quercetin. Besides its high-value nutraceutical importance, S. virgatum could be a natural candidate for developing well-accepted radioprotectant products capable of treating γ-irradiation-induced male infertility.

Design and Antioxidant Properties of Bifunctional 2H-Imidazole-Derived Phenolic Compounds-A New Family of Effective Inhibitors for Oxidative Stress-Associated Destructive Processes

The synthesis of inhibitors for oxidative stress-associated destructive processes based on 2H-imidazole-derived phenolic compounds affording the bifunctional 2H-imidazole-derived phenolic compounds in good-to-excellent yields was reported. In particular, a series of bifunctional organic molecules of the 5-aryl-2H-imidazole family of various architectures bearing both electron-donating and electron-withdrawing substituents in the aryl fragment along with the different arrangements of the hydroxy groups in the polyphenol moiety, namely derivatives of phloroglucinol, pyrogallol, hydroxyquinol, including previously unknown water-soluble molecules, were studied. The structural and antioxidant properties of these bifunctional 5-aryl-2H-imidazoles were comprehensively studied. The redox transformations of the synthesized compounds were carried out. The integrated approach based on single and mixed mechanisms of antioxidant action, namely the AOC, ARC, Folin, and DPPH assays, were applied to estimate antioxidant activities. The relationship “structure-antioxidant properties” was established for each of the antioxidant action mechanisms. The conjugation effect was shown to result in a decrease in the mobility of the hydrogen atom, thus complicating the process of electron transfer in nearly all cases. On the contrary, the conjugation in imidazolyl substituted phloroglucinols was found to enhance their activity through the hydrogen transfer mechanism. Imidazole-derived polyphenolic compounds bearing the most electron-withdrawing functionality, namely the nitro group, were established to possess the higher values for both antioxidant and antiradical capacities. It was demonstrated that in the case of phloroglucinol derivatives, the conjugation effect resulted in a significant increase in the antiradical capacity (ARC) for a whole family of the considered 2H-imidazole-derived phenolic compounds in comparison with the corresponding unsubstituted phenols. Particularly, conjugation of the polyphenolic subunit with 2,2-dimethyl-5-(4-nitrophenyl)-2H-imidazol-4-yl fragment was shown to increase ARC from 2.26 to 5.16 (10⁴ mol-eq/L). This means that the considered family of compounds is capable of exhibiting an antioxidant activity via transferring a hydrogen atom, exceeding the activity of known natural polyphenolic compounds.

Algae as a Source of Natural Flavors in Innovative Foods

As a result of their nutritive values, algae have been used as a food resource for centuries, and there is a growing interest to use them as enrichment ingredients in food products. However, food product acceptance by consumers is strongly linked to their organoleptic properties, especially the aroma, taste, and a combination of the two, flavor. With regard to edible algae, "fresh seashore", "seafood-like", "cucumber green", and "earthy" are descriptors commonly used to define their aromas. Several families of molecules participate in the diversity and peculiarities of algal aromas: pungent sulfur compounds and marine halogenated components but also herbaceous fatty acid derivatives and fruity-floral terpenoids. In both macroalgae (seaweeds) and microalgae, these compounds are studied from a chemistry point of view (identification and quantification) and a sensorial point of view, involving sensorial evaluation by panelists. As a whole food, a food ingredient, or a feed, algae are valued for their nutritional composition and their health benefits. However, because the acceptance of food by consumers is so strongly linked to its sensorial features, studies have been performed to explore the aromas of algae, their impact on food, their evolution through processing, and their ability to produce selected aromas using biotechnology. This review aims at highlighting algal aromas from seaweed and microalgae as well as their use, their handling, and their processing in the food industry.

Oxidative Quality of Dairy Powders: Influencing Factors and Analysis

Lipid oxidation (LO) is a primary cause of quality deterioration in fat-containing dairy powders and is often used as an estimation of a products shelf-life and consumer acceptability. The LO process produces numerous volatile organic compounds (VOC) including aldehydes, ketones and alcohols, which are known to contribute to the development of off-flavours in dairy powders. The main factors influencing the oxidative state of dairy powders and the various analytical techniques used to detect VOC as indicators of LO in dairy powders are outlined. As the ability to identify and quantify specific VOC associated with LO improves this review highlights how these techniques can be used in conjunction with olfactory and sensory analysis to better understand product specific LO processes with the aim of maximizing shelf-life without compromising quality.

Novel postharvest processing strategies for value-added applications of marine algae

Marine algae are regarded as a promising nutrients resource in future as they can be sustainably cultured without land and high investment. These macroalgae are now widely processed into food and beverages, fertilizers and animal feed. Furthermore, bioactive compounds such as polysaccharides and polyphenols in seaweeds have proven to have antibacterial, antiviral and antifungal properties that can be utilized in cosmeceuticals, nutraceuticals and pharmaceuticals. As a key procedure in seaweed production, the postharvest process not only requires more laboured and energy but also affect the quality of the final product significantly. This article reviewed all current postharvest processes and technologies of seaweed and addressed potential postharvest strategies for seaweed production. © 2021 Society of Chemical Industry.

Stability of Fucoxanthin in Pasteurized Skim and Whole Goat Milk

Obesity has become a worldwide problem giving rise to several health issues. Fucoxanthin, a marine carotenoid with anti-obesity activity, has potential application as a biofunctional ingredient in human food. The objective of this study was to evaluate the thermal stability of fucoxanthin at pasteurization temperature and, subsequently, its storage stability in goat whole milk (WM) and skim milk (SM) at refrigeration temperature for four weeks. Additionally, the effect of supplementation of fucoxanthin on the composition of milk, pH, acidity, color, and lipid oxidation of WM and SM was evaluated during the four week storage period. Fresh goat WM and SM were supplemented with fucoxanthin at a concentration of 10.67 µg/mL (2.56 mg/240 mL of milk, one serving), pasteurized at 64 °C for 30 min and stored at 4 °C for four weeks. The quantification of fucoxanthin in WM and SM was performed every week using a HPLC method. Moreover, the effect of supplementation of fucoxanthin on the composition of WM and SM was evaluated by a LactiCheck milk analyzer, and the color was evaluated by reflectance using a HunterLab colorimeter. Lipid oxidation, as the 2-thiobarbituric acid-reactive substances (TBARS) at A532, was determined using a Spectramax Plus spectrophotometer during storage. Data were analyzed by a split-plot design using PROC MIXED of SAS. The recovery yields of fucoxanthin from the pasteurized WM and SM were 96.17 ± 1.5 % and 96.89 ± 1.5 %, respectively. Both milks exhibited high recovery yields of fucoxanthin. Fucoxanthin was stable in goat WM and SM during storage at 4 °C for four weeks. The addition of fucoxanthin, at the concentration reported to have an anti-obesity effect in humans, to pasteurized WM and SM did not affect the composition or the physicochemical properties of milks but influenced the color, especially increasing the yellowness in the samples. These results revealed that goat milk can be used as a suitable matrix for the supplementation of fucoxanthin as a biofunctional ingredient in human foods.

Antimicrobials from Seaweeds for Food Applications

The exponential growth of emerging multidrug-resistant microorganisms, including foodborne pathogens affecting the shelf-life and quality of foods, has recently increased the needs of the food industry to search for novel, natural and eco-friendly antimicrobial agents. Macroalgae are a bio-diverse group distributed worldwide, known to produce multiple compounds of diverse chemical nature, different to those produced by terrestrial plants. These novel compounds have shown promising health benefits when incorporated into foods, including antimicrobial properties. This review aims to provide an overview of the general methods and novel compounds with antimicrobial properties recently isolated and characterized from macroalgae, emphasizing the molecular pathways of their antimicrobial mechanisms of action. The current scientific evidence on the use of macroalgae or macroalgal extracts to increase the shelf-life of foods and prevent the development of foodborne pathogens in real food products and their influence on the sensory attributes of multiple foods (i.e., meat, dairy, beverages, fish and bakery products) will also be discussed, together with the main challenges and future trends of the use of marine natural products as antimicrobials.

The possible role of the seaweed Ulva fasciata on ameliorating hyperthyroidism-associated heart inflammations in a rat model

Cardiovascular diseases are key complications primarily associated with hyperthyroidism disorders. The present study sought to ameliorate hyperthyroidism-mediated cardiovascular inflammations and related oxidative stress paradigms in experimental rats using the broadly distributed green seaweed Ulva fasciata. Forty-eight adult male albino rats were recruited and randomly classified into six groups. Hyperthyroidism was stimulated using L-thyroxine sodium at a dose of 100 μg/kg i.p. for 3 weeks daily. Further, 200 mg/kg b.wt. concentration of the U. fasciata methanolic (U. fasciata-MeOH) extract was the recommended dose and administrated orally to the hyperthyroid rats. The standard commercial drug "propranolol hydrochloride" was also tested at a dose of 10 mg/kg i.p. to compare the findings obtained from the seaweed extract. A combined treatment with the U. fasciata-MeOH extract and propranolol hydrochloride was also assessed. Our results implied that the treatment of hyperthyroid rats with the U. fasciata-MeOH extract significantly reduced serum levels of the thyroid hormones T3 and T4, proinflammatory cytokines (TNF-α, MPO, and CRP), triglycerides and total cholesterol, as well as the cardiac biomarkers CK-MB, LDH, and troponin to thresholds close to those of the standard drug. In addition, levels of high-density lipoprotein cholesterol (HDL-C) and interleukin 10 (IL-10) were significantly upregulated. Hyperthyroid rats only treated with propranolol hydrochloride, or with a combination of the drug and the seaweed extract, conferred the same observations. Histopathological architecture boosted our interesting findings where the myocardium tissues in hyperthyroid rats, administrated the U. fasciata-MeOH extract or/and propranolol hydrochloride, exhibited more or less a normal structure as the control, reflecting the potential cardiovascular recovery exerted by this seaweed extract. In vitro DPPH, ABTS, and FRAP antioxidant assays of the U. fasciata-MeOH extract showed an outstanding ROS-scavenging potential. HPLC analysis of the U. fasciata-MeOH extract unraveled an inestimable valuable array of phenolics (mainly p-coumaric, gallic, ferulic, chlorogenic, and syringic acids) and flavonoids (hesperidin, kaempferol, catechin, quercetin, and rutin). Conclusively, the seaweed U. fasciata is a profitable source of antioxidant polyphenolics characterized by having a pharmaceutical potential against hyperthyroidism-linked cardiovascular inflammations and oxidative stress patterns due to their substantial free radical quenching properties, and also via regulating the signalling pathways of the proinflammatory, lipid profile, and cardiac biomarkers.

Seaweed-based natural ingredients: Stability of phlorotannins during extraction, storage, passage through the gastrointestinal tract and potential incorporation into functional foods

Adding value to seaweed by extracting their different bioactive compounds and incorporating them into foods represent an interesting and strategic approach to diversify the functional foods offer. However, once harvested, fresh seaweed must overcome a sequence of crucial steps to confer their biological activity. Pre-processing operations and extraction processes, as well as long-term storage, play important roles in improving or decreasing the phlorotannins content. In their way to the gut (biological target), phlorotannins are exposed to the human gastrointestinal tract (GIT), where the physiological pH and digestive enzymes can significantly affect the phlorotannins' stability and thus, alter their biological activity. Besides, the subsequent incorporation into foodstuffs could be limited due to sensory issues, as tannins have been associated with astringency and bitter taste, and thus effective phlorotannins doses may negatively affect the sensory attributes of foods. These drawbacks expose the need of applying smart strategies to develop a final product providing the necessary protective mechanisms to maintain the active molecular form of phlorotannins up to the consumption time, also controlling their release upon arrival to the gut. In this context, the impact of these technological processes (from pre-processing to the passage through the GIT) on phlorotannins stability, as well as the innovative developed approaches to overcome these issues will be deeply discussed in this review. Besides, recent findings related to the phlorotannins' health benefits will be pointed out. Special attention on the potential incorporation of phlorotannins into functional foods will be also put it on.

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.

Evaluation of the impact of chlorophyll removal techniques on polyphenols in rosemary and thyme by-products

The impact of dechlorophyllization (n-hexane: water partitioning, activated charcoal bleaching, and ChloroFiltr® decolorization) on major polyphenols of two herbal by-products (rosemary and thyme) was assessed. The aim was to produce decolorized extracts for food preservation and improve the quantification of their main phenolics. Activated charcoal bleaching and ChloroFiltr® decolorization effectively removed the chlorophyll a and b, whereas traces were detected after n-hexane: water partitioning. Dechlorophyllized thyme extracts prepared using activated charcoal and ChloroFiltr® had the lowest relative antioxidant capacity index (RACI) values based on 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), ferric reducing antioxidant power (FRAP), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant assays. Conversely, rosemary extracts had positive RACI values following treatment with activated charcoal, whereas n-hexane led to a significant antioxidant loss. Chromatography-mass spectrometry analyses indicated that phenolic diterpenes (carnosol and carnosic acid), as well as rosmarinic acid were in general not significantly decreased (p ˃ .05) after activated charcoal treatment, while n-hexane maintained the flavonoids and phenolic acids with nonsignificant losses. PRACTICAL APPLICATIONS: Commercial exploitation of polyphenol-rich plant based extracts as natural antioxidant agents is impeded by their high chlorophyll content, which when incorporated in food products can result in products that do not meet the consumer expectations for appearance. This study has shown that the activated charcoal bleaching has potentials to remove chlorophyll and retain antioxidant polyphenols in particular diterpenes in fresh herb by-products. Moreover, the commonly used n-hexane was less effective in removing chlorophyll but retained the major flavonoids and phenolic acids. Thus, the choice of chlorophyll removal methods depend on retaining the class of antioxidant polyphenols abundant in the plant matrix.

Development of new food and pharmaceutical products: Nutraceuticals and food additives

The market of nutraceuticals and foods elaborated with natural additives are constantly growing and leading researchers and professionals of pharmaceutical and food industry to develop new products and reconsider the formulation of processed food. However, these products can only be insert into the market after extensive and well-performed scientific studies that clarify the mechanisms by which bioactive compounds can improve health status beyond nutrition or can replace conventional food additives perceived as "unhealthy" or "unfamiliar" by consumers. Therefore, scientific evidence regarding the actual health benefits and preservation/enhancement of food attributes are the crucial step in the exploration of nutraceuticals and natural food additives. In this context, several studies have been carried to identify and characterize natural bioactive compounds in aquaculture and related by-products for further production of nutraceuticals and food additives. The main purpose of this chapter is to highlight the most recent advances to explore extracts and isolated compounds from aquaculture and by-products to develop nutraceuticals and food additives.

Seaweed and seaweed-derived metabolites as prebiotics

Seaweeds and their bioactive compounds, particularly polysaccharides and phenolics can be regarded as great dietary supplements with gut health benefits and prebiotics. These components are resistant to digestion by enzymes present in the human gastrointestinal tract, also selectively stimulate the growth of beneficial gut bacteria and the production of fermentation products such as short chain fatty acids. Commonly, the health benefits of seaweed components are assessed by including them in an in vitro anaerobic fermentation system containing human fecal inocula that mimics the environment of the human large bowel. Regarding to the complex interactions between dietary components, gastrointestinal physiological processes, and gut microbiota are difficult to model in vitro. Consequently it is important to follow up the promising in vitro results with in vivo animal or human testing. The aim of this chapter is to have a comprehensive review on the application of seaweeds and seaweed-derived metabolites as prebiotics, and understand the trends, gaps and future directions of both scientific and industrial developments. This work contributes to develop and expand new platform of seaweed utilization for higher-value products, particularly to functional food and nutraceutical industries in order to serve the social demand for health awareness and support economic development.

Brown Macroalgae as Valuable Food Ingredients

Due to the balanced nutritional value and abundance of bioactive compounds, seaweeds represent great candidates to be used as health-promoting ingredients by the food industry. In this field, Phaeophyta, i.e., brown macroalgae, have been receiving great attention particularly due to their abundance in complex polysaccharides, phlorotannins, fucoxanthin and iodine. In the past decade, brown algae and their extracts have been extensively studied, aiming at the development of well-accepted products with the simultaneous enhancement of nutritional value and/or shelf-life. However, the reports aiming at their bioactivity in in vivo models are still scarce and need additional exploration. Therefore, this manuscript revises the relevant literature data regarding the development of Phaeophyta-enriched food products, namely those focused on species considered as safe for human consumption in Europe. Hopefully, this will create awareness to the need of further studies in order to determine how those benefits can translate to human beings.

Optimization of Phlorotannins Extraction from Fucus vesiculosus and Evaluation of Their Potential to Prevent Metabolic Disorders

Phlorotannins are phloroglucinol-based phenolic compounds, occurring particularly in brown macroalgae, that have been recognized for their promising bioactive properties. In this study, the extraction of phlorotannins from Fucus vesiculosus was evaluated with particular emphasis on the influential parameters, including the solvent concentration, solvent-solid ratio, extraction temperature and extraction time, using a single-factor design followed by a Box-Behnken design. The maximum total phlorotannin content, determined using the 2,4-dimethoxybenzaldehyde (DMBA) method, corresponded to 2.92 ± 0.05 mg of phloroglucinol equivalents/g dry seaweed (mg PGE/g DS), and was achieved for extracts carried out with acetone 67% (v/v), a solvent-solid ratio of 70 mL/g and temperature at 25 °C. This crude extract, together with a semi-purified phlorotannin fraction, were further evaluated for their anti-enzymatic capacity against α-glucosidase, α-amylase and pancreatic lipase, both showing promising inhibitory effects, particularly against α-glucosidase for which a greater inhibitory effect was observed compared to the pharmaceutical drug acarbose (IC50 = 4.5 ± 0.8 and 0.82 ± 0.3 μg/mL, respectively, against 206.6 ± 25.1 μg/mL). Additionally, the ultra-high-pressure liquid chromatography coupled to mass spectrometry (UHPLC-MS) analysis carried out on the ethyl acetate fraction revealed the presence of fucols, fucophlorethols, fuhalols and several other phlorotannin derivatives. Moreover, possible new phlorotannin compounds, including fucofurodiphlorethol, fucofurotriphlorethol and fucofuropentaphlorethol, have been tentatively identified in this extract. Overall, this study provides evidence that F. vesiculosus phlorotannin-rich extracts hold potential for the management of the activity of α-glucosidase, α-amylase and pancreatic lipase, which are well known to be linked to metabolic disorders such as diabetes and obesity.

Antimicrobial and Antibiofilm Activities of Sulfated Polysaccharides from Marine Algae against Dental Plaque Bacteria

Dental plaque biofilms cause various dental diseases; therefore, inhibiting the growths of the dental plaque bacteria which produce biofilms can be a strategy for preventing dental disease. Certain sulfated polysaccharides from marine algae exert antimicrobial activities against human bacterial pathogens in addition to their physiological benefits. On the basis of these observations, the antimicrobial and antibiofilm activities of sulfated polysaccharides from different marine algae were evaluated against dental plaque bacteria. Among the sulfated polysaccharides, a fucoidan from Fucus vesiculosus showed notable antimicrobial activities against the selected dental plaque bacteria, including some foodborne pathogenic bacteria. The minimum inhibitory concentrations were of 125 to 1000 µg mL-1. Regarding the antibiofilm activity, the fucoidan at the concentrations of above 250 µg mL-1 completely suppressed the biofilm formations and planktonic cell growths of Streptococcus mutans and S. sobrinus. However, no eliminative effect on the completed biofilm was observed. The fucoidan consisted of almost fucose base polysaccharide containing approximately 14.0% sulfate content. The average molecular weight of the fucoidan was changed by heat treatment (121 °C for 15 min) and it affected the antimicrobial activity.

Phycochemical Constituents and Biological Activities of Fucus spp

Seaweeds are known to be a good supply of key nutrients including carbohydrates, protein, minerals, polyunsaturated lipids, as well as several other health-promoting compounds capable of acting on a wide spectrum of disorders and/or diseases. While these marine macroalgae are deeply rooted in the East Asian culture and dietary habits, their major application in Western countries has been in the phycocolloid industry. This scenario has however been gradually changing, since seaweed consumption is becoming more common worldwide. Among the numerous edible seaweeds, members of the genus Fucus have a high nutritional value and are considered good sources of dietary fibers and minerals, especially iodine. Additionally, their wealth of bioactive compounds such as fucoidan, phlorotannins, fucoxanthin and others make them strong candidates for multiple therapeutic applications (e.g., antioxidant, anti-inflammatory, anti-tumor, anti-obesity, anti-coagulant, anti-diabetes and others). This review presents an overview of the nutritional and phytochemical composition of Fucus spp., and their claimed biological activities, as well as the beneficial effects associated to their consumption. Furthermore, the use of Fucus seaweeds and/or their components as functional ingredients for formulation of novel and enhanced foods is also discussed.

Fucaceae: A Source of Bioactive Phlorotannins

Fucaceae is the most dominant algae family along the intertidal areas of the Northern Hemisphere shorelines, being part of human customs for centuries with applications as a food source either for humans or animals, in agriculture and as remedies in folk medicine. These macroalgae are endowed with several phytochemicals of great industrial interest from which phlorotannins, a class of marine-exclusive polyphenols, have gathered much attention during the last few years due to their numerous possible therapeutic properties. These compounds are very abundant in brown seaweeds such as Fucaceae and have been demonstrated to possess numerous health-promoting properties, including antioxidant effects through scavenging of reactive oxygen species (ROS) or enhancement of intracellular antioxidant defenses, antidiabetic properties through their acarbose-like activity, stimulation of adipocytes glucose uptake and protection of β-pancreatic cells against high-glucose oxidative stress; anti-inflammatory effects through inhibition of several pro-inflammatory mediators; antitumor properties by activation of apoptosis on cancerous cells and metastasis inhibition, among others. These multiple health properties render phlorotannins great potential for application in numerous therapeutical approaches. This review addresses the major contribution of phlototannins for the biological effects that have been described for seaweeds from Fucaceae. In addition, the bioavailability of this group of phenolic compounds is discussed.

Application of seaweeds to develop new food products with enhanced shelf-life, quality and health-related beneficial properties

Edible seaweeds are a good source of antioxidants, dietary fibers, essential amino acids, vitamins, phytochemicals, polyunsaturated fatty acids, and minerals. Many studies have evaluated the gelling, thickening and therapeutic properties of seaweeds when they are used individually. This review gives an overview on the nutritional, textural, sensorial, and health-related properties of food products enriched with seaweeds and seaweed extracts. The effect of seaweed incorporation on properties of meat, fish, bakery, and other food products were highlighted in depth. Moreover, the positive effects of foods enriched with seaweeds and seaweed extracts on different lifestyle diseases such as obesity, dyslipidemia, hypertension, and diabetes were also discussed. The results of the studies demonstrated that the addition of seaweeds, in powder or extract form, can improve the nutritional and textural properties of food products. Additionally, low-fat products with less calories and less saturated fatty acids can be prepared using seaweeds. Moreover, the addition of seaweeds also affected the health properties of food products. The results of these studies demonstrated that the health value, shelf-life and overall quality of foods can be improved through the addition of either seaweeds or seaweed extracts.