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Schematic representation of the renin–angiotensin–aldosterone system (RAAS) and the hypertensive effect of angiotensin‐I‐converting enzyme (ACE‐I). Angiotensinogen is converted to the decapeptide angiotensin‐I by renin. ACE‐I cleaves the C‐terminal dipeptide His‐Leu of angiotensin‐I to form angiotensin‐II. Binding of angiotensin‐II to its receptor (AT1) stimulates the secretion of inositol 1,4,5‐triphosphate (IP3) and aldosterone, which induce arteriolar vasoconstriction and increased intravascular fluid volume, respectively, resulting in increased blood pressure. Within the kallikrein–kinin system, kallikrein converts kininogen to bradykinin, which induces arteriolar vasodilation by prostaglandin secretion and binding of bradykinin with its receptor, resulting in decreased blood pressure. However, the hypotensive effect of bradykinin is largely dependent on the rate of degradation by ACE‐I, which hydrolyzes bradykinin to form inactive metabolites.
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Population growth combined with increasingly limited resources of arable land and fresh water has resulted in a need for alternative protein sources. Macroalgae (seaweed) and microalgae are examples of under-exploited “crops”. Algae do not compete with traditional food crops for space and resources. This review details the characteristics of common...
Citations
... Microalgae thrive in both marine and freshwater environments, boasting a vast diversity of more than 200,000 species including cyanobacteria, with around 35,000 species identified to-date. Notably, the strains used for diverse commercial applications include Chlorella vulgaris, Arthrospira platensis, Arthrospira maxima, Haematococcus pluvialis, Dunaliella salina, Chlorella pyrenoidosa, Crypthecodinium cohnii, and Schizochytrium aggregatum [7]. Microalgae serve as a rich source of bioactive primary metabolites such as proteins, peptides, lipids, polysaccharides, and vitamins as well as secondary metabolites such as carotenoids, mycosporine-like amino acids (MAAs), phycobiliproteins, and phytosterols. ...
The increasing global population has led to a significant accumulation of food waste. It is important to focus on reducing food waste instead of disposal methods like landfilling and incineration, which have severe environmental impacts. Upcycling food waste has emerged as an effective strategy for repurposing discarded food into higher-value products. However, concerns about food safety and public acceptance of products directly produced from food waste persist. Consequently, there is growing interest in utilizing food waste rich in moisture and biodegradable organic compounds as a potential medium for cultivating microalgae. This review article examines the utilization of food waste as a culture medium for microalgae cultivation and the methods for treating food waste to enhance its nutrient content. Additionally, it discusses the influence of nutrients such as carbon, nitrogen, and phosphorus on microalgae growth and external factors such as pH and light intensity. The article also addresses the innovation of the food supply chain from environmental, social, and economic perspective, along with food safety and public acceptability concerns. Furthermore, it explores the legislative issues surrounding products derived from food waste and the end use of microalgae biomass produced from food waste. Overall, this review provides insight into the potential of microalgae cultivation using food waste, serving as a platform towards the realization of a circular bioeconomy.
... A second important use of microalgae derived proteins in the food industry is due to their nutritional quality to replace animal protein sources should contain all the EAA for the human diet. 40,41 Microalgae appear as a better alternative, as a rich source of some of EAA with low allergenic potential, unlike soy and milk, 36,42 for which it can be used as a sustainable alternative to meet the current global protein demand. 43 This study reported C. vulgaris and A. platensis as potential sources of carotenoids and considered their feasibility for use with FH treatment, which can be applied with fresh biomass under specific temperature and pressure conditions to obtain the targeted bioproducts. ...
The human body can easily convert β‐carotene into retinol (a precursor of vitamin A), a significant ingredient in dietary supplements. The need for commercial natural pigment production, including β‐carotene, has led to intensive research in this area. Processing after biosynthesis is a vital stage that involves the use of nontoxic solvents, efficient mechanical disruption of cells, and the isolation of the required compounds. With the growing popularity of green extraction methods and the increasing market demand for carotenoids due to their health benefits, the use of clean, nontoxic, flash‐hydrolyzed biomass for carotenoid production presents a significant advantage. Furthermore, the remaining biomass can serve as a protein source for animal feed, thereby aligning with the principles of the biorefinery concept. In this study, our aim was to optimize the disruption of cells in two microalgal species using flash hydrolysis (FH). We applied two distinct levels of pressure and four separate temperature conditions over a brief residence time. Following this, we employed an ethanol extraction method to assess the efficiency of carotenoid pigment extraction. Flash hydrolysis is a chemical‐free subcritical water‐based continuous‐flow process, injected with wet biomass slurry at a high temperature (150–250 °C) for a very short time (8–12 s) to obtain bioproducts. In this study, we discovered that the pigment β‐carotene constituted 0.04 to 0.3% of the dry biomass in the case of Chlorella vulgaris. Bands of lutein and zeaxanthin were also observed in the thin layer chromatography (TLC) analysis of the treated slurry. This was achieved under conditions of an effective temperature of 200 °C and a pressure of 1700 psi. The Arthrospira platensis (1Tex), β‐carotene yield was 0.014 to 0.021% of dry biomass. Some lutein and zeaxanthin bands were also found in the treated slurry with an effective temperature of 150 °C and 1000 psi pressure. This study reports pigment extraction by FH for the first time. It is a viable process to scale up high‐value natural products like carotenoids from microalgae at the industrial level without adverse environmental impacts. Due to low residence time, the temperature does not have a negative effect on pigments; cell rupture was accomplished effectively using water as a solvent. A considerable amount of pigment could be recovered from microalgae at specific combinations of temperature and pressure depending on the type of cell wall that microalgae possess.
... According to Costa et al. (2019), the commercial production of microalgae biomass occurs in a cycle, where the biomass is converted into various bioproducts and energy. Thus, all biomass fractions can be utilized, for example: carbohydrates can be used for bioethanol production (Cardias et al. 2020), lipids for biodiesel production and proteins for obtaining peptides (Lucakova et al. 2022) or as animal feed (Bleakley and Hayes 2017). ...
CO2 remediation is an urgent and challenging task to mitigate global climate change. Microalgae efficiently convert CO2 into biomass, offering potential for the development of bioproducts such as biofuels. Polyacrylonitrile (PAN) nanofibers, due to their porous structure and high surface area, can be integrated into microalgae cultivations to enhance CO2 capture. The adsorption performance of these nanofibers can be enhanced by incorporating compounds like monoethanolamine (MEA), and industrial CO2 chemical absorbent, which modifies the nitrogenous structures of the polymer to favor CO2 adsorption. This study aimed to produce PAN nanofibers with MEA for use in Spirulina sp. LEB 18 cultivation to asses microalgae growth and biomass composition. Uniform nanofibers with a mean diameter of 768 nm were developed with 1% of MEA and utilized in microalga grown. The highest CO2 biofixation rate and biomass productivity were achieved in cultivations with nanofibers without MEA (327.6 mg L⁻¹ d⁻¹ and 178.7 mg L⁻¹ d⁻¹, respectively). Biomass obtained in cultivations with nanofibers showed increased lipid (76.6 mg L⁻¹ d⁻¹) and protein (404 mg L⁻¹ d⁻¹) productivity, 2.1 and 1.7 higher, respectively, than the assay without nanofibers. Thus, PAN nanofibers act as CO2 adsorbents, enhancing gas biofixation by Spirulina sp. LEB 18, contributing to biomass production and increasing proteins and lipids yields.
Graphical Abstract
... Different types of bioactive peptides, phycobiliproteins, and MAAs are shown in Figure 3 below. Seaweeds serve as a rich protein source, with cultivation offering higher protein yields per unit area compared to terrestrial crops (2.5-7.5 tons/ha/year), although successful extraction is influenced by the presence of polysaccharides like alginates in brown seaweed or carrageenans in red seaweed [353]. Seasonal variations and habitat conditions affect the protein, peptide, and amino acid contents in seaweed; red algae generally exhibit higher contents (up to 47%) than green (between 9-26%), while brown algae have a lower concentration (3-15%) [354][355][356][357]. Proteins from all three macroalgae groups contain essential and non-essential amino acids, with bioactive peptides demonstrating numerous health benefits and high antioxidant properties, particularly those with low molecular weights, which are considered safer than synthetic molecules with reduced side effects [358][359][360][361][362][363][364][365]. ...
The term 'cosmeceutical' refers to cosmetic products that offer medicinal or drug-like benefits. Marine algae are rich sources of bioactive compounds, particularly carbohydrates and peptides, which have gained attention for their potential in cosmeceuticals. These compounds are abundant, safe, and have minimal cytotoxicity effects. They offer various benefits to the skin, including addressing rashes, pigmentation, aging, and cancer. Additionally, they exhibit properties such as antimicrobial, skin-whitening, anti-aging, antioxidant, and anti-melanogenic effects. This review surveys the literature on the cosmeceutical potentials of algae-derived compounds, focusing on their roles in skin whitening, anti-aging, anticancer, antioxidant, anti-inflammatory, and antimicrobial applications. The discussion also includes current challenges and future opportunities for using algae for cosmeceutical purposes.
... This review explores the characteristics of commonly consumed algae and their potential as protein sources, emphasizing protein quality, amino acid composition, and digestibility. Various protein extraction methods, including novel techniques, are discussed, along with potential applications in human nutrition, animal feed, and aquaculture (Bleakley and Hayes 2017). Green microalgae, rich in bioactive compounds and macronutrients, hold potential in food industries due to their high protein content and resilience. ...
The hunt for sustainable alternatives in the face of the growing global plastic issue has brought us to the intriguing field of bioplastics and biopolymers derived from algae. This chapter takes readers on a thorough exploration of the many dimensions of this emerging topic, delving into its possibilities, production methods, uses, and projected future. Exploring the world of algae, we reveal its various forms and traits, highlighting its potential as a feedstock for the manufacturing of bioplastics. The following sections explore the details of biopolymers that are present in algae, including proteins, polyhydroxyalkanoates (PHAs), cellulose, polysaccharides, and polysaccharides, revealing their special qualities and uses. This chapter then goes into production, including strategies for growing, extraction and purification, and sculpting algae bioplastics through mixing and modification, among other procedures. Optimal performance customization of bioplastics is highlighted, highlighting the fluid nature of material innovation. In the final section of the exploration, the future of algae-based bioplastics is explored, with an emphasis on innovative studies utilizing genetically modified algae, the identification of novel biopolymers, and state-of-the-art production techniques. This chapter discusses the remaining obstacles and presents a comprehensive plan for the broad use of products made from algae, putting a focus on consumer awareness, regulatory interventions, technological innovation, and cooperative efforts.
... 2. Algal Proteins: Algal proteins are increasingly utilized as functional ingredients in animal nutrition, offering a sustainable and nutrient-rich reservoir of amino acids, vitamins, and minerals. Their incorporation contributes to enhanced animal health and performance [37]. 3. Soybean Molasses: Employed as a functional feed ingredient, soybean molasses acts as a pelleting aid and imparts nutritional benefits, thus enhancing the overall quality of animal feed [38]. ...
This review delves into recent advancements in livestock research, focusing on genetic diversity, disease resistance, and immune function. Through an in-depth analysis of various studies, this review elucidates the intricate interplay of genetic factors influencing disease susceptibility and resilience in livestock populations. Investigations highlight the efficacy of functional ingredients, such as plant extracts and marine-derived compounds, in enhancing immune health and disease resistance in breeding animals. Additionally, the review examines the molecular mechanisms underlying the immunomodulatory effects of specific ingredients, shedding light on signaling pathways and gene expression profiles involved in bolstering immune function. Furthermore, the review explores emerging trends in livestock nutrition, including the utilization of fruit processing by-products to improve animal health and performance. Insights into the role of prebiotics in modulating gut microbiota and mitigating diet-related maladies provide valuable perspectives for enhancing livestock welfare and productivity. By synthesizing these findings, this review underscores the critical importance of genetic selection, dietary interventions, and immunomodulatory strategies in promoting the health and resilience of livestock populations.
... Algae, with their great taxonomic diversity, are a very promising natural source of various bioactive compounds, such as polyphenols, polysaccharides, carotenoids, and polyunsaturated fatty acids [4,5]. Algae are often exposed to extreme environmental conditions of light, salinity, and temperature. ...
In this study, different extraction methods and conditions were used for the extraction of antioxidants from brown macroalgae Fucus spiralis. The extraction methodologies used were ultrasound-assisted extraction (ultrasonic bath and ultrasonic probe), extraction with a vortex, extraction with an Ultra-Turrax® homogenizer, and high-pressure-assisted extraction. The extracts were analyzed for their total phenolic content (TPC) and their antioxidant activity, and evaluated through the 2,2-difenil-1-picrilhidrazil (DPPH) free radical scavenging method and ferric reducing antioxidant power (FRAP) assay. Ultrasonic probe-assisted extraction yielded the highest values of TPC (94.78–474.16 mg gallic acid equivalents/g extract). Regarding the antioxidant activity, vortex-assisted extraction gave the best DPPH results (IC50 1.89–16 µg/mL), while the highest FRAP results were obtained using the Ultra-Turrax® homogenizer (502.16–1188.81 μmol ascorbic acid equivalents/g extract). For each extraction method, response surface methodology was used to analyze the influence of the experimental conditions “extraction time” (t), “biomass/solvent ratio” (R), “solvent” (S, water % in water/ethanol mixture), and “pressure” (P) on TPC, DPPH, and FRAP of the F. spiralis extracts. In general, higher TPC content and higher antioxidant capacity (lower IC50 and higher FRAP) were obtained with higher R, t, and P, and lower S (higher ethanol %). The model regarding the combined effects of independent variables t, R, and S on the FRAP response values for vortex-assisted extractions best fitted the experimental data (R2 0.957), with optimal extraction conditions of t = 300 s, R = 50 g, and S = 25%.
... Along with their ability to accumulate lipids and hydrocarbons, under stress-inducing conditions, certain microalgal species synthesize distinct secondary metabolites, including pigments and vitamins, which result in added-value products with industrial applications, such as cosmetics, food, and pharmaceuticals [19]. Several microalgal strains are promising sources of protein, with some strains having a comparable content to that of meat, eggs, soybean, and milk [20]. Their use as an alternative feedstock for biofuels can help decrease the dependence on fossil fuels, while also reducing greenhouse gas emissions and mitigating the effects of climate change. ...
Botryococcus braunii, a colonial green microalga which is well-known for its capacity to synthesize hydrocarbons, has significant promise as a long-term source of feedstock for the generation of biofuels. However, cultivating and scaling up B. braunii using conventional aqua-suspended cultivation systems remains a challenge. In this study, we optimized medium components and light intensity to enhance lipid and hydrocarbon production in a multi-cultivator airlift photobioreactor. BBM 3N medium with 200 μmol/m²/s light intensity and a 16 h light–8 h dark regimen yielded the highest biomass productivity (110.00 ± 2.88 mg/L/day), as well as the highest lipid and hydrocarbon content. Cultivation in a flat-panel bioreactor resulted in significantly higher biomass productivity (129.11 ± 2.74 mg/L/day), lipid productivity (32.21 ± 1.31 mg/L/day), and hydrocarbon productivity (28.98 ± 2.08 mg/L/day) compared to cultivation in Erlenmeyer flasks and open 20-L raceway pond. It also exhibited 20.15 ± 1.03% of protein content including elevated levels of chlorophyll a, chlorophyll b, and carotenoids. This work is noteworthy since it is the first to describe fatty acid and hydrocarbon profiles of B. braunii during cobalt treatment. The study demonstrated that high cobalt concentrations (up to 5 mg/L of cobalt nitrate) during Botryococcus culture affected hydrocarbon synthesis, resulting in high amounts of n-alkadienes and trienes as well as lipids with elevated monounsaturated fatty acids concentration. Furthermore, pyrolysis experiments on microalgal green biomass and de-oiled biomass revealed the lipid and hydrocarbon compounds generated by the thermal degradation of B. braunii that facilitate extra economical value to this system.
... Consumption of this microalgal biomass is detrimental to both human and animal health because of the higher absorption characteristics of MA of heavy metals, herbicides, and other harmful compounds from saltwater (Rzymski et al. 2018). Appropriate safety precautions must be implemented to resolve such issues, and the permissible limit defined by food security organizations like Food and Drug Administration and EFSA (The European Food Safety Authority) must be followed (Bleakley and Hayes 2017). In addition, the acceptance of food products is influenced by its flavor and appearance. ...
Microalgae (MA) are the most abundant seaweeds with high nutritional properties. They are accepted as potential biocatalysts for the bioremediation of wastewater. They are widely used in food, feed, and biofuel industries and can potentially be food for future generations. MA-based purification of wastewater technology could be a universal alternative solution for the recovery of resources from wastewater for low-cost biomass feedstock for industry. They provide a wide range of functional components, viz. omega-3 fatty acids, along with a plenteous number of pigments such as ß-carotene, astaxanthin, lutein, phycocyanin, and chlorophyll, which are used extensively as food additives and nutraceuticals. Further, proteins, lipids, vitamins, and carbohydrates are described as nutritional characteristics in MA. They are investigated as single-cell protein, thickening/stabilizing agents, and pigment sources in the food industry. The review emphasizes the production and extraction of nutritional and functional components of algal biomass and the role of microalgal polysaccharides in digestion and nutritional absorption in the gastrointestinal tract. Further, the use of MA in the food industry was also investigated along with their potential therapeutic applications.
... Furthermore, macroalgae biomass has been discovered to be a high-quality protein-rich food, making it a sustainable alternative protein source to address current global security challenges [8]. It is well known that red macroalgae have high protein levels, which sometimes exceed conventional protein sources like soybeans, cereals, eggs, and fish [9]. Today, the macroalgae protein market is growing continuously and is projected to reach $1.131 billion by 2027 [10]. ...
... In recent years, numerous cell disruption and protein extraction techniques have been investigated to enhance the extraction yield and functional properties of macroalgae protein extracts [8]. Hence, several strategies for breaking the cell wall of algae have been evaluated to recover different components, including bead-beating [21,22], ultrasonication [23,24], microwave radiation [25], enzymatic hydrolysis [9,26], cell homogenizing [27], and high-pressure cell disruption [28]. All these extraction methods improve the mass transfer rate and increase the availability of protein and other high value-added components [29]. ...
... Despite the high nutritional value of algal proteins [9], their availability is limited by the rigidity of the algal membrane. For this reason, our study aimed to evaluate the proteins released in the aqueous media after different cell disruptions. ...
Abstract: In this study, the release of proteins and other biomolecules into an aqueous media from two red macroalgae (Sphaerococcus coronopifolius and Gelidium spinosum) was studied using eight different cell disruption techniques. The contents of carbohydrates, pigments, and phenolic compounds coextracted with proteins were quantified. In addition, morphological changes at the cellular level in response to the different pretreatment methods were observed by an optical microscope. Finally, the antioxidant capacity of obtained protein extracts was evaluated using three in vitro tests. For both S. coronopifolius and G. spinosum, ultrasonication for 60 min proved to be the most effective technique for protein extraction, yielding values of 3.46 ± 0.06 mg/g DW and 9.73 ± 0.41 mg/g DW, respectively. Furthermore, the highest total contents of phenolic compounds, flavonoids, and carbohydrates were also recorded with the same method. However, the highest pigment contents were found with ultrasonication for 15 min. Interestingly, relatively high antioxidant activities like radical scavenging activity (31.57-65.16%), reducing power (0.51-1.70, OD at 700 nm), and ferrous iron-chelating activity (28.76-61.37%) were exerted by the different protein extracts whatever the pretreatment method applied. This antioxidant potency could be attributed to the presence of polyphenolic compounds, pigments, and/or other bioactive substances in these extracts. Among all the used techniques, ultrasonication pretreatment for 60 min appears to be the most efficient method in terms of destroying the macroalgae cell wall and extracting the molecules of interest, especially proteins. The protein fractions derived from the two red macroalgae under these conditions were precipitated with ammonium sulfate, lyophilized, and their molecular weight distribution was determined using SDS-PAGE. Our results showed that the major protein bands were observed between 25 kDa and 60 kDa for S. coronopifolius and ranged from 20 kDa to 150 kDa for G. spinosum. These findings indicated that ultrasonication for 60 min could be sufficient to disrupt the algae cells for obtaining protein-rich extracts with promising biological properties, especially antioxidant activity.
