Spirulina for the food and functional food industries

Biological properties of vitamin B12

Vitamin B12, cobalamin, is indispensable for humans owing to its participation in two biochemical reactions: the conversion of l-methylmalonyl coenzyme A to succinyl coenzyme A, and the formation of methionine by methylation of homocysteine. Eukaryotes, encompassing plants, fungi, animals and humans, do not synthesise vitamin B12, in contrast to prokaryotes. Humans must consume it in their diet. The most important sources include meat, milk and dairy products, fish, shellfish and eggs. Due to this, vegetarians are at risk to develop a vitamin B12 deficiency and it is recommended that they consume fortified food. Vitamin B12 behaves differently to most vitamins of the B complex in several aspects, e.g. it is more stable, has a very specific mechanism of absorption and is stored in large amounts in the organism. This review summarises all its biological aspects (including its structure and natural sources as well as its stability in food, pharmacokinetics and physiological function) as well as causes, symptoms, diagnosis (with a summary of analytical methods for its measurement), prevention and treatment of its deficiency, and its pharmacological use and potential toxicity.

Increasing the sustainability of photoautotrophic microalgae production by minimising freshwater requirements

There are now several companies that are producing microalgae such as Arthrospira platensis, Chlorella vulgaris, and Dunaliella salina, among others. They are cultivated mainly in large-scale raceway and tubular photobioreactors. Microalgae production represents a sustainable alternative to conventional biomass production. Microalgae can be used to manufacture agricultural products, animal feed, food and other commercial products. The water requirements for cultivating microalgae are significant, exceeding 1 m3·kg-1. This value varies depending on the production strategy. One of the main reasons for water loss is evaporation, which is influenced by the photobioreactor location, the season, and the operating conditions. Efforts are being made to reduce water requirements and make microalgae production economically viable and more environmentally friendly. Several strategies are being investigated for reducing freshwater use in microalgae cultivation; these include reusing the culture medium and producing microalgae using seawater or wastewater. Such strategies not only reduce water consumption, but also reduce nutrient consumption and costs while increasing sustainability.

Spirulina (Arthrospira) cultivation in photobioreactors: From biochemistry and physiology to scale up engineering

Spirulina (Arthrospira) has been extensively applied in CO2 biofixation, wastewater purification, and value-added bioproducts preparation. Light availability plays a pivotal role in Spirulina photoautotrophic cultivation, which is primary determined by characteristics of incident light and distribution of light within photobioreactors (PBRs). To clarify the role of light in Spirulina photoautotrophic cultivation, this review first analyzes the processes of light delivery and conversion in suspended PBRs. Then, effects of key light characteristics, including light intensity, spectrum, and photoperiod, on Spirulina growth and intracellular biochemical components synthesis are comprehensively summarized. Recent advancements in innovative PBR designs aimed at enhancing light utilization efficiency and promoting Spirulina growth are also highlighted. Finally, potential future research directions in the field of Spirulina photoautotrophic cultivation are outlined. Overall, this work provides a theoretical foundation and technical guidance for improving Spirulina production and specific target products synthesis from prespectives of light conditions regulation and PBRs design.

Spotlight on the long-term effects of micro/nanoplastics exposure on Spirulina platensis: Algal cells, extracellular polymeric substances, and phycocyanin

Spirulina platensis (SP) provides humans with proteins and natural pigments. The effects of micro/nanoplastics (MNPs) on SP are of great interest. We focused on the effects of high concentrations (100-300 mg/L) of polystyrene MNPs on SP for 50 days. MNPs caused growth retardation, a decrease in peak concentration of algal cells, the emergence of surface cracks and pores, and stimulated the secretion of extracellular polymeric substances that promoted heterogeneous aggregation of SP. During the first 35 days, there were significant differences between the exposure groups in the phycocyanin concentration, yield and purity and the ratio of phycocyanin to phycobiliprotein, with the higher MNPs concentration resulting in lower values, whereas on day 50 there were no statistically significant differences in any of these metrics between the control or exposure groups. This study enriches the knowledge about the long-term effects of MNPs on SP for microalgae culture and food industry.

Unraveling the unique bioactivities of highly purified C-phycocyanin and allophycocyanin

BACKGROUND

The blue-green microalgae Spirulina, used in human nutrition for centuries, includes phycobiliproteins such as C-phycocyanin (CPC) and allophycocyanin (APC). Assessing their unique bioactivities separately is difficult as they have similar properties, such as molecular weight and isoelectric point. In the present study, we aimed to separate CPC and APC and to evaluate their bioactivities. CPC and APC were separated using a hydrophobic membrane and ammonium sulfate, which promotes reversible and specific protein binding to the membrane. Spectroscopic analysis, HPLC, and SDS-PAGE revealed a successful separation of CPC and APC. Their bioactivities were evaluated through CCK- 8 assays for anticancer activity, radical scavenging assays for antioxidant activity, and albumin denaturation assays for anti-inflammatory activity, respectively.

RESULTS

The results revealed that highly purified APC showed 40% higher anticancer activity than the control, whereas CPC increased the viability of cancer cells, resulting in a 30% decrease in anticancer activity compared to the control. In contrast, highly purified CPC showed approximately 25% higher antioxidant activity and twice as much anti-inflammatory activity as APCs; moreover, the presence of both showed higher antioxidant activity.

CONCLUSION

This study provides important insights into the unique bioactivities of CPC and APC for their appropriate application as anticancer, antiphlogistic, and antioxidant agents.

Phycochemistry and pharmacological significance of filamentous cyanobacterium Spirulina sp

The cyanobacterium, Spirulina sp. is a photosynthetic blue-green alga with essential nutrients, vitamins nucleic acids, proteins, carbohydrates, fatty acids and pigments carotenes; and phycocyanins are the significant components having immunomodulatory, anti-inflammatory properties, which are used in food and cosmetics industries. Spirulina sp. can play an important role in human and animal nutrition for potential health benefits due to their phycochemical and pharmaceutical significance. This study highlights antibacterial, antifungal, antiviral, antioxidant, nephroprotective, cardioprotective, anticancer, neuroprotective, anti-aging, anti-inflammatory, and immunomodulatory properties. It highlights anti-anemic, antidiabetic, probiotic, anti-malarial, anti-obesity and weight loss, anti-genotoxicity, anti-thrombic, radioprotective, and detoxifying effects of Spirulina sp. Pharmaceutical studies indicate it may improve heart health and add to the treatment of diabetes, obesity and weight loss. It can play a major role in protecting the environment by recycling wastewater and providing food for humans and animals. Spirulina sp. can supply ingredients for aquaculture and agricultural feeds, pigments, antioxidants, and essential omega-3 oils, among other human health and wellness products. The amino acid of Spirulina is among the greatest qualititavely of any plant, even higher than that of soybean. Furthermore, cyanobacterium Spirulina sp. could be a future antimicrobial drug agent.

Impact of Spirulina Supplementation on Obesity, Hypertension, Hyperglycemia, and Hyperlipidemia: A Systematic Review

Aims: This systematic review evaluates how Spirulina supplementation impacts human metabolic syndrome. This review encompasses a broad spectrum of Spirulina supplementation studies, including variations in dosage, trial duration, participants, and the subsequent effects on human metabolic syndrome. Methods: The method involves searching for articles from the Scopus and PubMed databases (up to 2023) to identify relevant studies on Spirulina supplementation. The journal database related to the study was examined using the systematic review approach. Results: Out of 527 articles related to Spirulina supplementation, 13 articles were determined to be suitable for human clinical studies. The treatment is performed at 20 mg to 6 g within 17-360 days. Spirulina contains macro- and micronutrients, vitamins, and minerals that are beneficial for health, as well as several bioactives that play a role in improving metabolic syndrome. This seaweed pigment can reduce obesity, body mass index (BMI), hypertension, hyperglycemia, and dyslipidemia. Its tripeptides lower blood pressure while gamma linoleic acid and glycolipids improve lipid profile. The findings show that Spirulina supplementation improves human metabolic syndrome. It included obesity, hypertension, hyperglycemia, and hyperlipidemia. Conclusion: Spirulina supplementation in humans has a positive effect on metabolic syndrome. It is due to phycocyanin, L-isoleucyl-L-glutaminyl-L-proline (Ile-Gln-Pro), gamma-linolenic acid, and the glycolipid H-b2. However, the form of use, dosage, and treatment should be further researched to determine the right amount for each metabolic syndrome problem.

Comparison of Pressurized Water Extraction With Ultrasound Assisted Extraction for Isolation of Phycobiliproteins From Arthrospira platensis (Spirulina)

INTRODUCTION

Cyanobacterium Arthrospira platensis (AP) (Nordstedt) Gomont contains high content of phycobiliproteins (PBP), which are an important source for food industry. Methods effectively extracting proteins contained in AP cells are demanded to provide a supply of the material. Water-based extraction methods are advisable due to the high solubility of the PBP.

OBJECTIVES

Extraction techniques such as ultrasound assisted extraction (UAE) and pressurized water extraction (PWE) are popular due to their environmental friendliness, better extraction efficiency, and faster extraction process. In this paper, efficiency of the two methods is compared.

MATERIALS AND METHODS

PWE along with UAE is utilized for release of PBP from the AP cells. The extraction parameters including time, temperature, pressure, and ultrasound intensity are tested to obtain the most efficient setup. The methods were evaluated using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and the replicates of PWE extracts were further analyzed by capillary isoelectric focusing with laser-induced fluorescence (cIEF-LIF).

RESULTS

The developed PWE method using higher pressure treatment at lower temperature was significantly faster than UAE methods, and the SDS-PAGE results showed a high content of phycobiliproteins in the extracts. cIEF-LIF analysis showed that the sequential PWE of individual samples was repeatable, and the mild extraction provided a fluorescent profile similar to the commercially available C-phycocyanin standard.

CONCLUSION

Pressurized water extraction was shown to be an efficient, rapid, and well-automated extraction method for AP proteins in general, including bioactive phycobiliproteins. Obtained results encourage the use of PWE in small-scale analytical applications for primary extraction of proteins.

Integration of Fluorescence Spectroscopy into a Photobioreactor for the Monitoring of Cyanobacteria

Phytoplankton are essential to aquatic ecosystems but can cause harmful algal blooms (HABs) that threaten water quality, aquatic life, and human health. Developing new devices based on spectroscopic techniques offers a promising alternative for rapid and accurate monitoring of aquatic environments. However, phytoplankton undergo various physiological changes throughout their life cycle, leading to alterations in their optical properties, such as autofluorescence. In this study, we present a modification of a low-cost photobioreactor designed to implement fluorescence spectroscopy to analyze the evolution of spectral signals during phytoplankton growth cycles. This device primarily facilitates the characterization of changes in autofluorescence, providing valuable information for the development of future spectroscopic techniques for detecting and monitoring phytoplankton. Additionally, real-time testing was performed on cyanobacterial cultures, where changes in autofluorescence were observed under different conditions. This work demonstrates a cost-effective implementation of spectroscopic techniques within a photobioreactor, offering a preliminary analysis for the future development of functional field devices for monitoring aquatic ecosystems.

Exploring the biotechnological applications of Spirulina maxima: a comprehensive review

The Spirulina maxima algae is a phototrophic, multicellular, filamentous cyanobacteria of greenish blue tones, without ramifications and is characterized mainly by its helical form, thickness of approximately 3 to 12 µm and length of 500 µm; its development depends on factors such as temperature, light intensity, pH, aeration speed, carbon dioxide concentration, carbon source, nitrogen source which determine its chemical composition, which is composed of proteins, carbohydrates, lipids, minerals, and vitamins; due to this, it is widely used in industries such as food, pharmaceutical, cosmetics, and energy to obtain different products of great value. This S. maxima review addresses morphological characteristics, growth factors, growth methods, and metabolites of biotechnological interest and biotechnological applications for the S. maxima microalgae. A brief review of the enzyme production capacity of S. maxima and other microalgae is also presented, in addition to mentioning some areas of opportunity to study these and the economic viability of implementing a biorefinery with an integrated approach for the production of biomass and metabolites of biotechnological relevance based on the control of growth variables and the productive and economic efficiency of the process is discussed.

In vitro gas production and rumen fermentation for diets containing increasing levels of Panicum maximum cv. Mombasa with or without spirulina

This study was designed to evaluate the effect of substituting alfalfa hay with graded levels panicum maximum without or with graded levels of spirulina supplementation on rumen fermentation and nutrient degradability. The evaluation was achieved through an in vitro study, rumen fluid was obtained from adult sheep aged 2 years (fed clover hay), immediately after slaughter. Experimental diets were formulated as isonitrogenous and isocaloric and contained 40% forage. Forage composition was altered by substituting alfalfa hay with graded levels of panicum maximum hay, so that treatment diets contained 0, 25, 50, 75, and 100% of the forage from panicum maximum for treatments R1, R2, R3, R4, and R5, respectively. Additionally, each treatment was further supplemented with graded levels of spirulina at the following rates: 0, 0.5, 1.5, 2, 2.5, and 3 mg/g. Results indicated that gas production after 24 h per g DM, OM and DDM has a positive linear relationship with spirulina supplementation level (R2 = 0.80, 0.83, and 0.93, respectively). The gas production increased by increasing the level of Spirulina. However negative linear relationships were recorded between gas production per g DM, OM, DDM and alfalfa substitution level (R2 = 0.97, 0.95, and 0.96, respectively) which the gas production decreased as the substitution level increased. In vitro degradability of dry and organic matter was decreased by the increment of Panicum maximum and Spirulina supplementation levels and vice versa, until 2 mg/g of Spirulina (p < .0001). The addition of Spirulina significantly (p < .0001) increased total volatile fatty acids (TVFA) and NH3 concentration, until 2mg/g, while the addition of Panicum maximum hay significantly increased NH3 concentration, until it reached at (R4). In conclusion, the substitution of alfalfa hay with graded levels of Panicum maximum hay may be reduce nutrients degradability and gas production while supplementing diets with graded level of spirulina improve degradability and ruminal fermentation parameters.

Seaweeds-derived proteins and peptides: preparation, virtual screening, health-promoting effects, and industry applications

Seaweed, a promising source of nutritional proteins, including protein hydrolysates, bioactive peptides, phycobiliproteins, and lectins with multi-biological activities. Seaweeds-derived proteins and peptides have attracted increasing interest for their potential applications in dietary supplements, functional foods, and pharmaceuticals industries. This work aims to comprehensively review the preparation methods and virtual screening strategies for seaweed-derived functional peptides. Additionally, it elucidates their diverse biological activities, mechanisms of action, and industrial applications. Enzymatic hydrolysis appears as the most effective method for preparing functional peptides from seaweeds. Computational virtual screening has also proven to be a valuable strategy for assessing the nature of the peptides. Seaweeds-derived proteins and peptides offer numerous health benefits, including alleviation of oxidative stress, anti-diabetic, anti-hypertensive, anti-inflammatory, anti-obesity, anti-cancer, and anti-microbial activities. Studies indicate that proteins hydrolysates and peptides derived from seaweeds with low molecular weight and aromatic and/or hydrophobic amino acids are particularly significant in contributing to these diverse bio-activities. Furthermore, seaweeds-derived proteins and peptides hold great promise for industrial applications owing to the broad spectrum of bio-functional effects. They can be used as active ingredients in food products or pharmaceuticals for disease prevention and treatment, and as food preservatives, potentially with fewer side effects.

Effect of Chlorella pyrenoidosa and Spirulina platensis powder on the physicochemical, structural, and rheological properties of rice starch: A comparative study

The effect of Chlorella pyrenoidosa (CP) and Spirulina platensis (SP) at concentrations of 0 %-12 % on the properties of rice starch (RS) was investigated. Compared with pure RS, the addition of CP and SP powder decreased the viscosity, increased the gelatinization temperature, and promoted the retrogradation of RS gel. However, when CP was added at 12 % and SP at 8 %, retrogradation inhibition was reduced. At these concentrations, the relative crystallinity of the CP mixture increased by 57.37 %, whereas that of SP increased by 48.13 %. Scanning electron microscopy revealed that the addition of low amount of CP and SP reduced porosity. CP and SP powder facilitated the conversion of bound water to free water and contributed to the weakening of the viscoelasticity of the RS gel. CP powder likely had a more detrimental effect on the short-term storage properties of RS than SP powder. These results provide theoretical support for the development of RS-based products and the innovative utilization of microalgae.

Role of gut microbiota in rheumatoid arthritis: Potential cellular mechanisms regulated by prebiotic, probiotic, and pharmacological interventions

Rheumatoid arthritis (RA) is a chronic autoimmune disease that primarily affects joints and multiple organs and systems, which is long-lasting and challenging to cure and significantly impacting patients' quality of life. Alterations in the composition of intestinal flora in both preclinical and confirmed RA patients indicate that intestinal bacteria play a vital role in RA immune function. However, the mechanism by which the intestinal flora is regulated to improve the condition of RA is not fully understood. This paper reviews the methods of regulating gut microbiota and its metabolites through prebiotics, probiotics, and pharmacological interventions, and discusses their effects on RA. Additionally, it explores the potential predictive role of cellular therapy mechanisms of intestinal flora in treating RA. These findings suggest that restoring the ecological balance of intestinal flora and regulating intestinal barrier function may enhance immune system function, thereby improving rheumatoid arthritis. This offers new insights into its treatment.

Characterization of Spirulina-derived extracellular vesicles and their potential as a vaccine adjuvant

Spirulina is an edible cyanobacterium that increasingly gaining recognition for it untapped potential in the biomanufacturing of pharmaceuticals. Despite the rapidly accumulating information on extracellular vesicles (EVs) from most other bacteria, nothing is known about Spirulina extracellular vesicles (SPEVs). This study reports the successful isolation, characterization and visualization of SPEVs for the first time and it further investigates the potential therapeutic benefits of SPEVs using a mouse model. SPEVs were isolated using ultracentrifugation and size-exclusion-chromatography. Cryo-Transmission Electron Microscopy revealed pleomorphic outer-membrane-vesicles and outer-inner-membrane-vesicles displaying diverse shapes, sizes and corona densities. To assess short- and long-term immune responses, mice were injected intraperitoneally with SPEVs, which demonstrated a significant increase in neutrophils and M1 macrophages at the injection site, indicating a pro-inflammatory effect induced by SPEVs without clinical signs of toxicity or hypersensitivity. Furthermore, SPEVs demonstrated potent adjuvanticity by enhancing antigen-specific IgG responses in mice by over 100-fold compared to an unadjuvanted model vaccine antigen. Mass-spectrometry identified 54 proteins within SPEVs, including three protein superfamily members linked to the observed pro-inflammatory effects. Our findings highlight the potential of SPEVs as a new class of vaccine adjuvant and warrant additional studies to further characterize the nature of the immune response.

Nutraceutical tablets: Manufacturing processes, quality assurance, and effects on human health

Consumers are increasingly focused on food products' nutritional content and health aspects. Nutraceutical tablets containing nutritional supplements have seen remarkable progress and are well-known for their precise dosage, which can improve consumer health by increasing the intake of bioactive compounds and vital nutrients. Oral nutraceuticals are frequently used to enhance consumer well-being, with around 80% of products being in solid form. This manuscript aims to thoroughly analyze and summarize the gathered literature using various search engines to investigate key trends in the market, the components involved, and the functional impact of nutraceutical tablets. Furthermore, the manuscript explores various nutraceutical tablets such as chewable tablets, gelling capsules, vitamin tablets, spirulina tablets, and bran tablets. A perspective is provided on multiple production and manufacturing methods of nutraceutical tablets, along with comparing these processes. Following this, evaluating quality characteristics and enforcing quality assurance procedures have been emphasized. The manuscript discussed the physiological breakdown of ingestible nutraceutical tablets in the human body and the possible toxic effects of the components found in these tablets. Furthermore, the focus is on producing nutraceutical tablets in a more environmentally friendly manner, tackling sustainability issues, offering solutions, and delving into potential opportunities. This manuscript will create a significant platform for people from the research, scientific, and industrial fields seeking novel and inventive projects.

Effect of a weight loss diet with or without Spirulina supplementation on serum lipids and antioxidant capacity of overweight dogs

Obesity is a major health issue in dogs associated with disturbances in lipid metabolism and oxidative stress. Spirulina has been shown to have hypolipidemic and antioxidant effects in various animal species. No such data regarding dogs are available, however. The present study aimed to investigate the effect of a therapeutic high-protein, high-fiber weight loss diet, with or without Spirulina supplementation, on biochemical parameters of overweight dogs, with particular reference to serum lipids and plasma antioxidant capacity. Thirty-two dogs completed a double-blind randomized placebo-controlled trial in which they received either Spirulina (S) or placebo (P) tablets in a body weight-dependent amount for 12 weeks; at the same time, both groups were fed the same calorie-restricted diet. Dogs were weighed weekly and calorie restriction was adjusted accordingly to ensure a 1% body weight loss per week. Blood samples were collected at baseline (T0), after 6 weeks (T1), and after 12 weeks (T2). No difference in body weight loss (S: -11.9 ± 0.8%, P: -10.6 ± 0.8%, p = 0.229) was detected between groups at T2. After 6 weeks and an average weight loss of around 6% (S: -6.7 ± 0.6%, P: -5.9 ± 0.6, p = 0.276), significant reductions of serum total cholesterol, glucose, alkaline phosphatase, paraxonase-1 (all p < 0.0001) and gamma-glutamyltransferase (p < 0.018) were observed in both groups, regardless of supplementation. Plasma antioxidant capacity increased significantly in both groups at T2 (p = 0.0003). Serum triglycerides decreased significantly from T0 to T1 in the Spirulina group (p < 0.0001) but not in the placebo group (p = 0.28); as for the difference between groups, a non-significant trend (p = 0.098) was detected. A significantly higher percentage of dogs (p = 0.028) in the Spirulina group achieved a serum triglycerides reduction > 15% compared to baseline at T1 and > 30% at T2. A treatment effect (p = 0.0416) was found for bilirubin, which decreased only in the Spirulina group. In conclusion, a weight loss of around 6% achieved with a high-protein, high-fiber hypocaloric diet is sufficient to induce significant positive metabolic effects and improve lipid, glucose, and liver enzyme values. Plasma antioxidant capacity was tested in dogs undergoing a weight loss program for the first time, demonstrating that overweight individuals are in a deficient status and that a weight loss of around 10% is able to restore values comparable to those of healthy individuals. The results of this study suggest that Spirulina may manifest a hypotriglyceridemic effect in dogs, even if further research is needed to infer causation. The role Spirulina that supplementation plays in bilirubin metabolism and its related beneficial effect is also worth exploring.

Spirulina-An Invaluable Source of Macro- and Micronutrients with Broad Biological Activity and Application Potential

With population growth expected in the near future and the planet's limited resources, alternative food sources are already being looked for. In this context, spirulina is called the food of the future due to its rich nutritional composition. This blue-green alga is primarily a valuable source of protein (55-70%) containing all essential amino acids. In its composition, it also contains unsaturated fatty acids, minerals, vitamins, and pigments, including the valuable protein-pigment complex-phycocyanin. Due to its high content of complete protein and minerals such as iron and calcium, it is an excellent addition to diets, especially those of vegans and vegetarians. Despite several limitations to the use of spirulina, including its distinctive marine flavour, low consumer awareness, or relatively high price, scientists are attempting to enrich many food products with the microalga. This is supported not only by the improved nutritional composition of the fortified product but also by spirulina's impact on sustainable food production. Therefore, this review aims to create consumer attention by presenting spirulina as a valuable and sustainable food source with health-promoting potential and great future significance.

Industrial Production of Functional Foods for Human Health and Sustainability

Functional foods significantly affect social stability, human health, and food security. Plants and microorganisms are high-quality chassis for the bioactive ingredients in functional foods. Characterised by precise nutrition and the provision of both nutritive and medicinal value, functional foods serve a as key extension of functional agriculture and offer assurance of food availability for future space exploration efforts. This review summarises the main bioactive ingredients in functional foods and their functions, describes the strategies used for the nutritional fortification and industrial production of functional foods, and provides insights into the challenges and future developments in the applications of plants and microorganisms in functional foods. Our review aims to provide a theoretical basis for the development of functional foods, ensure the successful production of new products, and support the U.N. Sustainable Development Goals, including no poverty, zero hunger, and good health and well-being.

Recent Advancements in Production and Extraction Methods of Phycobiliprotein C-phycocyanin by Arthrospira (Spirulina) platensis: A Mini Review

Arthrospira platensis has been utilized as a food source since ancient times due to its rich nutrient profile. In recent years, its popularity as a dietary supplement has soared, especially due to the presence of a water-soluble phycobiliprotein, C-phycocyanin C (C-PC), which is abundant and notable for its fluorescent properties. C-PC contains the chromophore phycocyanobilin B (PCB-B), a tetrapyrrole molecule, that is why it plays a dual role as a food colorant and as nutraceutical. However, comprehensive studies have mostly evaluated C-PC's broader health-promoting properties, particularly its antioxidative and anti-inflammatory effects, which are linked to its ability to contrast oxidative stress and related pathological conditions. That is why this review explores recent advancements in optimizing culture conditions to enhance C-PC and PCB-B production, with a particular emphasis on novel extraction and purification techniques that increase yield and bioactivity. This focus on efficient production methods is crucial for expanding the commercial and therapeutic applications of C-PC, contributing to its growing relevance in the food and pharmaceutical industries.

Antiviral potential of spirulina in individuals with human immunodeficiency virus or Hepatis C virus infections: A systematic review and meta-analysis

BACKGROUND

Spirulina, a cyanobacterium or blue-green algae that contains phycocyanin, nutritional supplementation has been evaluated in patients living with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) due to its antiviral properties. This supplementation may be beneficial in low resource settings when awaiting antiretroviral therapy (ART) for HIV. This review aimed to evaluate the effectiveness of Spirulina supplement in antiviral-naïve HIV- and HCV-infected patients by assessing its immunological effect (Cluster of Differentiation 4 or CD-4 T-cell count) and disease progression (viral load).

METHODS

We searched PubMed, Cochrane Library, Scopus, and Web of Science from inception through January 23, 2024. Two authors independently performed the study selection, data extraction, and risk of bias assessment. We pooled data by using a random-effects model and evaluated publication bias by a funnel plot.

RESULTS

We identified 5552 articles, 5509 excluded at the title and abstract stage with 44 studies making it to the full text review. Of these 6 studies met the eligibility for inclusion in the final analysis as follows: 4 randomized controlled trials (RCTs) and 2 non-RCTs. The pooled results of the Spirulina intervention found significant improvements in biomarkers of clinical outcomes, viral load (VL) and CD4 T-cell (CD4) counts, in participants of the treatment group compared to controls; the VL had an overall Cohen's d effect size decrease of -2.49 (-4.80, -0.18) and CD4 had an overall effect size increase of 4.09 (0.75, 7.43). [Cohen's d benchmark: 0.2 = small effect; 0.5 = medium effect; 0.8 = large effect].

CONCLUSIONS

Findings from this systematic review showed a potential beneficial effect of Spirulina supplementation in HIV- and HCV-infected patients by increasing CD4 counts and decreasing viral load. However, further research in larger controlled clinical trials is needed to fully investigate the effect of this nutritional supplement on clinically relevant outcomes, opportunities for intervention, optimal dose, and cost-benefit of Spirulina supplementation.

3D printing of Pickering emulsions, Pickering foams and capillary suspensions - A review of stabilization, rheology and applications

Pickering emulsions and foams as well as capillary suspensions are becoming increasingly more popular as inks for 3D printing. However, a lack of understanding of the bulk rheological properties needed for their application in 3D printing is potentially stifling growth in the area, hence the timeliness of this review. Herein, we review the stability and bulk rheology of these materials as well as the applications of their 3D-printed products. By highlighting how the bulk rheology is tuned, and specifically the inks storage modulus, yield stress and critical balance between the two, we present a rheological performance map showing regions where good prints and slumps are observed thus providing clear guidance for future ink formulations. To further advance this field, we also suggest standard experimental protocols for characterizing the bulk rheology of the three types of ink: capillary suspension, Pickering emulsion and Pickering foam for 3D printing by direct ink writing.

Fabrication and characterization of bovine serum albumin-phycocyanobilin conjugate: effect on antioxidant and ligand-binding properties

BACKGROUND

Phycocyanobilin (PCB) is an open-chain blue tetrapyrrole chromophore of C-phycocyanin (C-PC), a major chromoprotein derived from the cyanobacterium Arthrospira platensis having numerous health-promoting effects. Relying on the ability of PCB to attach to the sulfhydryl group of proteins, we propose a new method for covalent attachment of PCB to bovine serum albumin (BSA) as a means of its functionalization.

RESULTS

Traut's reagent (TR, 2-iminothiolane), modifying lysine residues, was used to optimize the introduction of sulfhydryl groups in BSA. A higher degree of BSA thiolation by TR induces more profound alterations of its structure, resulting in minor oligomerization and aggregation. A 50-fold molar excess of TR was found to be the optimal, balancing thiolation level and adverse effect on protein structure. PCB was covalently attached to newly introduced sulfhydryl groups at pH 9 at 20-fold PCB/BSA ratio. An increase in the TR/BSA molar ratio leads to increased efficiency of PCB conjugation with thiolated BSA. Compared to native BSA, BSA-PCB conjugate binds quercetin with similar affinity but has higher antioxidant activity and increased oxidative stability.

CONCLUSIONS

PCB-modified BSA could serve as a stable, food-compatible carrier of bioactive PCB, but also bind other ligands that would be protected from oxidative damage due to the high antioxidant potential of covalently bound PCB. Thiolation by TR is, at the same time, a simple method for the covalent functionalization of virtually any protein by bioactive PCB or for obtaining PCB-based fluorescent probes. © 2024 Society of Chemical Industry.

Manufacturing processes, additional nutritional value and versatile food applications of fresh microalgae Spirulina

Spirulina is capable of using light energy and fixing carbon dioxide to synthesize a spectrum of organic substances, including proteins, polysaccharides, and unsaturated fatty acids, making it one of the most coveted food resources for humanity. Conventionally, Spirulina products are formulated into algal powder tablets or capsules. However, the processing and preparation of these products, involving screw pump feeding, extrusion, high-speed automation, and high-temperature dewatering, often result in the rupture of cell filaments, cell fragmentation, and the unfortunate loss of vital nutrients. In contrast, fresh Spirulina, cultivated within a closed photobioreactor and transformed into an edible delight through harvesting, washing, filtering, and sterilizing, presents a refreshing taste and odor. It is gradually earning acceptance as a novel health food among the general public. This review delves into the manufacturing processes of fresh Spirulina, analyzes its nutritional advantages over conventional algal powder, and ultimately prospects the avenues for fresh Spirulina's application in modern food processing. The aim is to provide valuable references for the research and development of new microalgal products and to propel the food applications of microalgae forward.

Spirulina/Arthrospira/Limnospira-Three Names of the Single Organism

Recent advances in research techniques have enabled rapid progress in the study of spirulina, an ancient edible cyanobacteria. Nowadays, spirulina species are classified into three genera: Spirulina, Arthrospira, and Limnospira. The latter now refers to industrially manufactured spirulina strains. Whole-genome sequencing revealed gene clusters involved in metabolite production, and the physiology of spirulina. Omics technologies demonstrated the absence of hazardous compounds in spirulina cells, confirming the safety of this biomass as a food product. Spirulina is a good source of different chemicals used in food manufacturing, food supplements, and pharmaceuticals. Spirulina's enrichment with inherent biologically active substances makes it a potential supplier of natural products for dietary and pharmaceutical applications. Spirulina is also a prospective component of both terrestrial and space-based life support systems. Here, we review current breakthroughs in spirulina research and clarify fallacies that can be found in both professional literature and public media.

Effect of Arthrospira platensis (Spirulina) Fortification on Physicochemical, Nutritional, Bioactive, Textural, and Sensory Properties of Vegan Basil Pesto

The high protein content of several microalgae species makes them an excellent addition to various food products, increasing their nutritional value. In this study, vegan basil pesto was designed and enriched with 1% and 2% Arthrospira platensis (spirulina). The pesto obtained was characterized by increased protein content (up to 40% more) and had a rich mineral composition, including up to three times more iron and 25% more calcium, among others. The increase of spirulina addition in the pesto also increased the content of polyphenols (up to 50% more) and flavonoids (up to 39% more). The fortified products had higher antioxidant activity against ABTS (up to 484.56 ± 2.16 μM Trolox/g) and DPPH (up to 392.41 ± 13.58 μM Trolox/g). The addition of spirulina will affect the hardness of the sauce, while in the other texture parameters (adhesiveness, springiness, and cohesion), there were no significant differences between the control and spirulina-fortified pesto. Although the pesto with spirulina was significantly darker in color (ΔE 8.83 and 12.05), consumers still rated it highly. All quality parameters of pesto with a 1% spirulina addition were rated the highest, contributing to the highest overall rating of the product (4.56). An increase in spirulina addition to 2% resulted in a decrease in the overall pesto rating (4.01), but still remains a good result compared to the control (4.22).

Trends in extracting protein from microalgae Spirulina platensis, using innovative extraction techniques: mechanisms, potentials, and limitations

Microalgal, species are recognized for their high protein content, positioning them as a promising source of this macronutrient. Spirulina platensis, in particular, is noteworthy for its rich protein levels (70 g/100 g dw), which are higher than those of meat and legumes. Incorporating this microalgae into food can provide various benefits to human health due to its diverse chemical composition, encompassing high amount of protein and elevated levels of minerals, phenolics, essential fatty acids, and pigments. Conventional techniques employed for protein extraction from S. platensis have several drawbacks, prompting the exploration of innovative extraction techniques (IETs) to overcome these limitations. Recent advancements in extraction methods include ultrasound-assisted extraction, microwave-assisted extraction, high-pressure-assisted extraction, supercritical fluid extraction, pulse-electric field assisted extraction, ionic liquids assisted extraction, and pressurized liquid extraction. These IETs have demonstrated efficiency in enhancing protein yield of high quality while maximizing biomass utilization. This comprehensive review delves into the mechanisms, applications, and drawbacks associated with implementing IETs in protein extraction from S. platensis. Notably, these innovative methods offer advantages such as increased extractability, minimized protein denaturation, reduced solvent consumption, and lower energy consumption. However, safety considerations and the synergistic effects of combined extraction methods warrant further exploration and investigation of their underlying mechanisms.

Green microbes: Potential solutions for key sustainable development goals

The latest assessment of progress towards the Sustainable Development Goals (SDGs) has identified major obstacles, such as climate change, global instability and pandemics, which threaten efforts to achieve the SDGs even by 2050. Urgent action is needed, particularly to reduce poverty, hunger and climate change. In this context, microalgae are emerging as a promising solution, particularly in the context of food security and environmental sustainability. As versatile organisms, microalgae offer nutritional benefits such as high-quality proteins and essential fatty acids, and can be cultivated in non-arable areas, reducing competition for resources and improving the sustainability of food systems. The role of microalgae also includes other applications in aquaculture, where they serve as sustainable alternatives to animal feed, and in agriculture, where they act as biofertilizers and biostimulants. These microorganisms also play a key role in interventions on degraded land, stabilizing soils, improving hydrological function and increasing nutrient and carbon availability. Microalgae therefore support several SDGs by promoting sustainable agricultural practices and contributing to land restoration and carbon sequestration efforts. The integration of microalgae in these areas is essential to mitigate environmental impacts and improve global food security, highlighting the need for increased research and development, as well as public and political support, to exploit their full potential to advance the SDGs.

Unveiling the impact of additives on structural integrity, thermal and color stability of C-phycocyanin - Agar hydrocolloid

C-Phycocyanin and sugar (C-PC/S) blended agar hydrocolloid was prepared and its rheological, thermo-functional and morphological properties were examined based on the fluorescence excitation-emission matrix profile. Sucrose (40%, w/v) determined as a superior preservative, maintaining the native conformation of C-PC effectively. C-PC/S exhibited enhanced structural integrity with high storage modulus (G') and 86.4% swelling index. FT-IR demonstrated strong intramolecular bonding. TGA revealed that the presence of sucrose prolonged the devolatilization peak up to 325 °C, with a degradation rate of -2.273 mg/min, it the thermal stability. C-PC/S fortified hydrocolloid in ice cream (5.0% w/w), reduced melting rate up to five times. In conclusion, sucrose as a promising enhancer of color stability and structural integrity for C-PC, and this combination effectively improves the functional and rheological properties. Further, the findings exposed the agar hydrocolloid as a potential enhancer of color retention and improved performance for various food and cosmetic products.

Biomedical engineering utilizing living photosynthetic cyanobacteria and microalgae: Current status and future prospects

Cyanobacteria are the only prokaryotes capable of performing oxygenic photosynthesis on Earth. Besides their traditional roles serving as primary producers, cyanobacteria also synthesize abundant secondary metabolites including carotenoids, alkaloids, peptides, which have been reported to possess medicinal potentials. More importantly, the advancement of synthetic biology technology has further expanded their potential biomedical applications especially using living/engineered cyanobacteria, providing promising and attractive strategies for future disease treatments. To improve the understanding and to facilitate future applications, this review aims to discuss the current status and future prospects of cyanobacterial-based biomedical engineering. Firstly, specific properties of cyanobacteria related with biomedical applications like their natural products of bioactive compounds and heavy metal adsorption were concluded. Subsequently, based on these properties of cyanobacteria, we discussed the progress of their applications in various disease models like hypoxia microenvironment alleviation, wound healing, drug delivery, and so on. Finally, the future prospects including further exploration of cyanobacteria secondary metabolites, the integration of bioactive compounds synthesized by cyanobacteria in situ with medical diagnosis and treatment, and the optimization of in vivo application were critically presented. The review will promote the studies related with cyanobacteria-based biomedical engineering and its practical application in clinical trials in the future.

Biomass-Derived Catalytically Active Carbon Materials for the Air Electrode of Zn-Air Batteries

Given the growing environmental and energy problems, developing clean, renewable electrochemical energy storage devices is of great interest. Zn-air batteries (ZABs) have broad prospects in energy storage because of their high specific capacity and environmental friendliness. The unavailability of cheap air electrode materials and effective and stable oxygen electrocatalysts to catalyze air electrodes are main barriers to large-scale implementation of ZABs. Due to the abundant biomass resources, self-doped heteroatoms, and unique pore structure, biomass-derived catalytically active carbon materials (CACs) have great potential to prepare carbon-based catalysts and porous electrodes with excellent performance for ZABs. This paper reviews the research progress of biomass-derived CACs applied to ZABs air electrodes. Specifically, the principle of ZABs and the source and preparation method of biomass-derived CACs are introduced. To prepare efficient biomass-based oxygen electrocatalysts, heteroatom doping and metal modification were introduced to improve the efficiency and stability of carbon materials. Finally, the effects of electron transfer number and H2O2 yield in ORR on the performance of ZABs were evaluated. This review aims to deepen the understanding of the advantages and challenges of biomass-derived CACs in the air electrodes of ZABs, promote more comprehensive research on biomass resources, and accelerate the commercial application of ZABs.

Evaluation of the functional properties of a protein isolate from Arthrospira maxima and its application in a meat sausage

Arthrospira maxima is a microalga that has been collected in Lake Texcoco in the Valley of Mexico since pre-Hispanic times and has been a traditional food source due to its high biomass production and protein content (50-60 %), making it promising for protein extraction. In this context, a protein isolate was obtained from powdered biomass of Arthrospira maxima (PbAm) by alkaline solubilization (pH 11) and isoelectric precipitation (pH 4.2). Arthrospira maxima protein isolate (AmPI) presented higher protein content (82.58 %) and total amino acids compared to PbAm. Functional properties of AmPI were evaluated in comparison with PbAm and soy protein isolate (SPI). Protein extraction resulted in a significant increase in protein solubility (PS) and foaming capacity (FC) of up to 87.78 % and 238.10 %, respectively. Emulsifying capacity (EC) of AmPI was superior to that of PbAm and SPI in pH range 5-7. Inclusion of AmPI as a partial substitute for SPI in the formulation of meat sausages was evaluated by implementing four treatments: T1 (15 % AmPI, 85 % SPI), T2 (10 % AmPI, 90 % SPI), T3 (5 % AmPI, 95 % SPI) and T4 (0 % AmPI, 100 % SPI). Although the texture attributes remained unchanged, a significant reduction in color parameters was observed as the concentration of AmPI increased. An inclusion of 15 % AmPI significantly enhanced the nutritional quality of meat sausages. Results highlight the excellent properties of AmPI, confirming Arthrospira maxima as a promising protein source in the food industry.

Potential benefits of microalgae intake against metabolic diseases: beyond spirulina-a systematic review of animal studies

CONTEXT

Microalgae are a diverse source of bioactive molecules, such as polyphenols, carotenoids, and omega-3 fatty acids, with beneficial properties in biomarkers of metabolic diseases. Unlike the rest of the microalgae genera, Arthrospira sp., commonly called spirulina, has been widely studied.

OBJECTIVE

This review aims to describe the current knowledge about microalgae, besides spirulina, focusing on their beneficial properties against metabolic diseases.

DATA SOURCES

A systematic research of MEDLINE (via PubMed), Cochrane, and Scopus databases was conducted to identify relevant studies published after January 2012. In vivo animal studies including microalgae consumption, except for spirulina, that significantly improved altered biomarkers related to metabolic diseases were included. These biomarkers included body weight/composition, glucose metabolism, lipid metabolism, oxidative damage, inflammation markers, and gut microbiota.

DATA EXTRACTION

After the literature search and the implementation of inclusion and exclusion criteria, 37 studies were included in the revision out of the 132 results originally obtained after the application of the equation on the different databases.

DATA ANALYSIS

Data containing 15 microalgae genera were included reporting on a wide range of beneficial results at different levels, including a decrease in body weight and changes in plasma levels of glucose and lipoproteins due to molecular alterations such as those related to gene expression regulation. The most reported beneficial effects were related to gut microbiota and inflammation followed by lipid and glucose metabolism and body weight/composition.

CONCLUSIONS

Microalgae intake improved different altered biomarkers due to metabolic diseases and seem to have potential in the design of enriched foodstuffs or novel nutraceuticals. Nevertheless, to advance to clinical trials, more thorough/detailed studies should be performed on some of the microalgae genera included in this review to collect more information on their molecular mechanisms of action.

Investigation of the Elemental Contents, Functional and Nutraceutical Properties of Kefirs Enriched with Spirulina platensis, an Eco-friendly and Alternative Protein Source

In this study, the effect of the use of S. platensis, which is presented as an eco-friendly and alternative protein source, in the production of kefir, a probiotic dairy product, on various physicochemical properties as well as FAA, ACE inhibitory activity, proteolysis, TPC, DPPH, ABTS+, and mineral values was investigated. It was observed that the addition of S. platensis at different ratios to the kefir samples had a statistically very significant (p < 0.01) effect on all physicochemical analyses; L. mesenteroides count; all amino acids except isoleucine, aspartic acid, and glutamic acid; ACE inhibitory activity, TN, TCAN, TCAN/TN, mM Gly, TPC, DPPH, ABTS+, Na, Mg, K, and Fe. In plain kefir samples, mineral contents were determined by order of K > P > Na > Ca > Mg > Zn >> Fe > Cr > Cr > Mn. Furthermore, a general increase was observed in FAA, ACE inhibitory activity, TPC, DPPH, ABTS+, and mineral values, as well as in the counts of Lactococcus spp. and L. mesenteroides in the samples, depending on the proportion of S. platensis added, compared to plain kefir samples. In this context, it was concluded that the addition of S. platensis to kefir at different rates could meet various components required by the body on a daily basis and result in a nutraceutical product.

Space-Efficient 3D Microalgae Farming with Optimized Resource Utilization for Regenerative Food

Photosynthetic microalgae produce valuable metabolites and are a source of sustainable food that supports life without compromising arable land. However, the light self-shading, excessive water supply, and insufficient space utilization in microalgae farming have limited its potential in the inland areas most in need of regenerative food solutions. Herein, this work develops a 3D polysaccharide-based hydrogel scaffold for vertically farming microalgae without needing liquid media. This liquid-free strategy is compatible with diverse microalgal species and enables the design of living microalgal frameworks with customizable architectures that enhance light and water utilization. This approach significantly increases microalgae yield per unit water consumption, with an 8.8-fold increase compared to traditional methods. Furthermore, the dehydrated hydrogels demonstrate a reduced size and weight (≈70% reduction), but readily recover their vitality upon rehydration. Importantly, valuable natural products can be produced in this system including proteins, carbohydrates, lipids, and carotenoids. This study streamlines microalgae regenerative farming for low-carbon biomanufacturing by minimizing light self-shading, relieving water supply, and reducing physical footprints, and democratizing access to efficient aquatic food production.

Algae: A promising and sustainable protein-rich food ingredient for bakery and dairy products

The consumer demand for protein rich foods urges the exploration for novel products of natural origin. Algae can be considered as a gold mine of different bioactive compounds, among which protein is distributed in significant amounts i.e., around 30% and can even reach to 55-60% in some cyanobacteria. Bakery and dairy products are extensively consumed worldwide due to product diversification and innovation. However, incorporation of algae biomass can lead to the development of green colour and fishy flavour that usually is not accepted in such products. Therefore, isolation and application of algae-derived proteins opens a new door for food industry. The present review provides a comprehensive understanding of incorporation of algae as a protein-rich ingredient in bakery and dairy products. The paper provides a deep insight for all the possible recent trends related to production and extraction of algae proteins accompanied by their incorporation in bakery and dairy foods.

Identification and molecular docking of tyrosinase inhibitory peptides from allophycocyanin in Spirulina platensis

BACKGROUND

Tyrosinase, a copper-containing metalloenzyme with catalytic activity, is widely found in mammals. It is the key rate-limiting enzyme that catalyzes melanin synthesis. For humans, tyrosinase is beneficial to the darkening of eyes and hair. However, excessive deposition of melanin in the skin can lead to dull skin color and lead to pigmentation. Therefore, many skin-whitening compounds have been developed to decrease tyrosinase activity. This study aimed to identify a new tyrosinase inhibitory peptide through enzymatic hydrolysis, in vitro activity verification, molecular docking, and molecular dynamics (MD) simulation.

RESULTS

A tripeptide Asp-Glu-Arg (DER) was identified, with a '-CDOCKER_Energy' value of 121.26 Kcal mol-1 . DER has effective tyrosinase inhibitory activity. Research shows that its half maximal inhibitory concentration value is 1.04 ± 0.01 mmol L-1 . In addition, DER binds to tyrosinase residues His85, His244, His259, and Asn260, which are key residues that drive the interaction between the peptide and tyrosinase. Finally, through MD simulation, the conformational changes and structural stability of the complexes were further explored to verify and supplement the results of molecular docking.

CONCLUSION

This experiment shows that DER can effectively inhibit tyrosinase activity. His244, His259, His260, and Asn260 are the critical residues that drive the interaction between the peptide and tyrosinase, and hydrogen bonding is an important force. DER from Spirulina has the potential to develop functional products with tyrosinase inhibition. © 2024 Society of Chemical Industry.

Sourdough process and spirulina-enrichment can mitigate the limitations of colon fermentation performances of gluten-free breads in non-celiac gut model

In this work, the impact of gluten free (GF) breads enriched with spirulina on the ecology of the colon microbiota of non-celiac volunteers was investigated. Simulation of digestion of GF breads was conducted with an in vitro gut model. Microbiomics and metabolomics analyses were done during colon fermentations to study the modulation of the microbiota. From the results, a general increase in Proteobacteria and no reduction of detrimental microbial metabolites were observed in any conditions. Notwithstanding, algae enriched sourdough breads showed potential functionalities, as the improvement of some health-related ecological indicators, like i) microbiota eubiosis; ii) production of bioactive volatile organic fatty acids; iii) production of bioactives terpenes. Our results indicate that a sourdough fermentation and algae enrichment can mitigate the negative effect of GF breads on gut microbiota of non-celiac consumers.

Challenges in Functional Food Products with the Incorporation of Some Microalgae

Much attention has been given to the use of microalgae to produce functional foods that have valuable bioactive chemicals, including essential amino acids, polyunsaturated fatty acids, vitamins, carotenoids, fiber, and minerals. Microalgal biomasses are increasingly being used to improve the nutritional values of foods because of their unique nutrient compositions that are beneficial to human health. Their protein content and amino acid composition are the most important components. The microalgal biomass used in the therapeutic supplement industry is dominated by bio-compounds like astaxanthin, β-carotene, polyunsaturated fatty acids like eicosapentaenoic acid and docosahexaenoic acid, and polysaccharides such as β-glucan. The popularity of microalgal supplements is growing because of the health benefits of their bioactive substances. Moreover, some microalgae, such as Dunaliella, Arthrospira (Spirulina), Chlorella, and Haematococcus, are commonly used microalgal species in functional food production. The incorporation of microalgal biomass leads not only to enhanced nutritional value but also to improved sensory quality of food products without altering their cooking or textural characteristics. Microalgae, because of their eco-friendly potential, have emerged as one of the most promising and novel sources of new functional foods. This study reviews some recent and relevant works, as well as the current challenges for future research, using different methods of chemical modification in foods with the addition of a few commercial algae to allow their use in nutritional and sensory areas. It can be concluded that the production of functional foods through the use of microalgae in foods has become an important issue.

Beneficial Effects of Spirulina Supplementation in the Management of Cardiovascular Diseases

In recent decades, as a result of rising mortality rates due to cardiovascular diseases (CVDs), there has been a growing urgency to find alternative approaches to conventional pharmaceutical treatment to prevent the onset of chronic diseases. Arthrospira platensis, commonly known as Spirulina, is a blue-green cyanobacterium, classified as a "superfood", used worldwide as a nutraceutical food supplement due to its remarkable nutritional value, lack of toxicity, and therapeutic effects. Several scientific studies have evaluated the cardioprotective role of Spirulina. This article presents a comprehensive review of the therapeutic benefits of Spirulina in improving cardio- and cerebrovascular health. It focuses on the latest experimental and clinical findings to evaluate its antihypertensive, antidiabetic, and antihyperlipidemic properties. The objective is to highlight its potential in preventing and managing risk factors associated with cardiovascular disease (CVD).

A multiplex metabolomic approach for quality control of Spirulina supplement and its allied microalgae (Amphora & Chlorella) assisted by chemometrics and molecular networking

Microalgae species are of economic importance regarded as "green gold" being rich in bioactive compounds. Spirulina and Chlorella are the most popular microalgal species and are marketed as healthy food supplements. At the same time, Amphora holds potential as a source of healthy lipids and essential fatty acids. Yet, there are considerable variations in their reported chemical composition, and less is known about their compositional differences. A multiplexed metabolomic approach was adopted for the quality control (QC) of Spirulina supplements and to compare its constitutive metabolome to Chlorella and Amphora. The adopted protocol comprised gas chromatography-mass spectrometry (GC-MS), ultra-high performance liquid chromatography coupled with high-resolution tandem mass spectrometry (UPLC-HRMS/MS), and ultraviolet-visible spectrophotometry (UV/Vis) for mapping their primary and secondary metabolome. Interestingly, UPLC-HRMS/MS analysis delineated the abundance of fatty acids in Amphora versus glycolipids enrichment in Spirulina, and porphyrins were the main pigments identified in Spirulina, with scarce occurrence in Chlorella. Orthogonal projections to latent structures discriminant analysis (OPLS-DA) analysis of GC-MS data set revealed palmitic acid, 3-mannobiose, and glyceryl-glycoside as being most enriched in Spirulina, versus sucrose and leucine in Chlorella and Amphora, respectively. Despite being of low discriminatory potential, UV/Vis OPLS-DA modeling showed that Spirulina was distinguished with the UV absorbances of carotenoids and chlorophyll pigments, as indicated by its OPLS-DA derived S-plot. Our study provides a QC approach for the analysis of the microalgal species and poses alternative spectral and compositional markers for their discrimination.

Metabolomic Profile of Arthrospira platensis from a Bulgarian Bioreactor-A Potential Opportunity for Inclusion in Dietary Supplements

The present study aims to elucidate the metabolomic profile of Arthrospira platensis grown in a bioreactor in Bulgaria. The results show that Arthrospira platensis has a high content of mannose, 137.02 mg g-1, and vitamin A (retinol)-10.3 μg/100 g. High concentrations of calcium, sulfur, and zinc distinguish its elemental composition. The freeze-dried powder contained 15.81 ± 0.45% dietary fiber, 50.16 ± 0.25% total protein content, and 1.22 ± 0.11% total fat content. Among the unsaturated fatty acids with the highest content is α-linolenic acid (25.28%), while among the saturated fatty acids, palmitic acid prevails (22.55%). Of the sterols in the sample, β-sitosterol predominated. There is no presence of microcystins LR, RR, YR, and nodularin. Therefore, Arthrospira platensis grown in a Bulgarian bioreactor is safe for use in the pharmaceutical and food industries. Many of the organic compounds found have applications in medicine and pharmacology and play an important role in biochemical processes in the body. Therefore, Arthrospira platensis grown in Bulgaria has a high potential for use as an independent food supplement or in combination with other natural products.

Valorization of Food Waste into Single-Cell Protein: An Innovative Technological Strategy for Sustainable Protein Production

The rapidly increasing population and climate change pose a great threat to our current food systems. Moreover, the high usage of animal-based and plant-based protein has its drawbacks, as these nutritional sources require many hectares of land and water, are affected by seasonal variations, are costly, and contribute to environmental pollution. Single-cell proteins (SCPs) are gaining a lot of research interest due to their remarkable properties, such as their high protein content that is comparable with other protein sources; low requirements for land and water; low carbon footprint; and short production period. This review explores the use of food waste as a sustainable feedstock for the advancement of SCP processes. It discusses SCP studies that exploit food waste as a substrate, alongside the biocatalysts (bacteria, fungi, yeast, and microalgae) that are used. The operational setpoint conditions governing SCP yields and SCP fermentation routes are elucidated as well. This review also demonstrates how the biorefinery concept is implemented in the literature to improve the economic potential of "waste-to-protein" innovations, as this leads to the establishment of multiproduct value chains. A short section that discusses the South African SCP scenario is also included. The technical and economic hurdles facing second-generation SCP processes are also discussed, together with future perspectives. Therefore, SCP technologies could play a crucial role in the acceleration of a "sustainable protein market", and in tackling the global hunger crisis.

The microalgae's ability to accumulate selected trace elements studied by ICP-MS/MS and chemometric methods

BACKGROUND

Microalgae can be used in different branches of industry, including cosmetology, pharmaceutics and the food industry, information on their ability to accumulate different elements becomes more important. The microalgae biomass grown in the media enriched in elements can increase the accumulation of different ions and give a possibility to control the contents of the various elements.

METHODS

The aim of the study was to determine the total content of metals in microalgae by tandem mass spectrometry with inductively coupled plasma (ICP-MS/MS) and analysis of the contents of particular metals as a function of the type of microalgae and conditions of cultivation. As the adverse effects of metals on the health of humans and animals have been well-documented and the use of microalgae has increased, the knowledge of metal contents in them is of particular importance in control of their quality.

RESULTS

Analysis of results permitted distinction of three main groups of microalgae with similar total metal content levels. Moreover, the results revealed the ways of stimulating more significant accumulation of selected elements (for example, Se concentration in control algae 0.279 µg g-1, in the algae cultivated in enriched medium - 219.7 µg g-1). They indicated the possible correlations between the accumulation of different ions. The result obtained shows a significant effect of metal accumulation and has a considerable impact on the differentiation of Arthrospira platensis grown in the medium enriched in different elements (selenium, zinc, chromium) (p ≤ 0.05).

CONCLUSIONS

Particular impact on the content of selected elements had the conditions of cultivation (type of support) and the microalgae species. Although the one species as the most significant source of selected elements cannot be indicated, it is possible to control the accumulation by the composition of the medium.

The potential, challenges, and prospects of the genus Spirulina polysaccharides as future multipurpose biomacromolecules

Spirulina has been widely used worldwide as a food and medicinal ingredient for centuries. Polysaccharides are major bioactive constituents of Spirulina and are of interest because of their functional properties and unlimited application potential. However, the clinical translation and market industrialization of the polysaccharides from genus Spirulina (PGS) are retarded due to the lack of a further understanding of their isolation, bioactivities, structure-activity relationships (SARs), toxicity, and, most importantly, versatile applications. Herein, we provide an overview of the extraction, purification, and structural features of PGS; meanwhile, the advances in bioactivities, SARs, mechanisms of effects, and toxicity are discussed and summarized. Furthermore, the applications, potential developments, and future research directions are scrutinized and highlighted. This review may help fill the knowledge gap between theoretical insights and practical applications and guide future research and industrial application of PGS.

Effect of seawater on the biomass composition of Spirulina produced at a pilot-scale

The microalga Arthrospira platensis BEA 005B was produced in 11.4 m3 raceway photobioreactors and a culture medium based on commercial fertilisers and either freshwater or seawater. The biomass productivity of the reactors operated at a fixed dilution rate of 0.3 day-1 decreased from 22.9 g·m-2·day-1 when operated using freshwater to 16.3 g·m-2·day-1 when the biomass was produced using seawater. The protein content of the biomass produced in seawater was lower; however, the content of essential amino acids including valine, leucine and isoleucine was higher. Seawater also triggered the production of carotenoids and altered the synthesis and accumulation of fatty acids. For example, the biomass produced using seawater showed a 319% and 210% higher content of oleic and eicosenoic acid, respectively. The results demonstrate that it is possible to produce the selected microalga using seawater after an adaptation period and that the composition of the produced biomass is suitable for food applications.

Muscle cell proliferation using water-soluble extract from nitrogen-fixing cyanobacteria Anabaena sp. PCC 7120 for sustainable cultured meat production

Muscle cell cultivation, specifically the culture of artificial meat from livestock-derived cells in serum-free media is an emerging technology and has attracted much attention. However, till now, the high cost of production and environmental load have been significant deterrents. This study aims to provide an alternate growth-promoting substance that is free from animal derivatives and lowers nitrogen pollution. We have extracted water-soluble compounds from the filamentous nitrogen-fixing cyanobacteria Anabaena sp. PCC 7120 by the ultrasonication method. The heat-inactivated and molecular weight separation experiments were conducted to identify the bioactive compound present in the extract. Finally, the compounds soluble in water (CW) containing the water-soluble pigment protein, phycocyanin as a bioactive compound, was added as a growth supplement to cultivate muscle cells such as C2C12 muscle cells and quail muscle clone 7 (QM7) cells to analyze the effectiveness of the extract. The results indicated that CW had a positive role in muscle cell proliferation. A three-dimensional (3-D) cell-dense structure was fabricated by culturing QM7 cells using the extract. Furthermore, the nitrogen-fixing cyanobacterial extract has vast potential for cultured meat production without animal sera in the near future.

Fourteen-Days Spirulina Supplementation Increases Hemoglobin, but Does Not Provide Ergogenic Benefit in Recreationally Active Cyclists: A Double-Blinded Randomized Crossover Trial

Spirulina supplementation has been reported to increase hemoglobin concentration as well as a variety of cardiorespiratory and lactate-based performance parameters during maximal and submaximal states of exercise. This study investigates the efficacy of supplementing a 6 g/day dosage of spirulina for 14-days in recreationally active individuals, analyzing cardiorespiratory parameters during maximal and submaximal cycling as well as the potential mechanistic role of hemoglobin augmentation. 17 recreationally active individuals (Male = 14, Female = 3, Age 23 ± 5 years, V̇O2max 43.3 ± 8.6 ml/min·kg) ingested 6 g/day of spirulina or placebo for 14-days in a double-blinded randomized crossover study, with a 14-day washout period between trials. Participants completed a 20-min submaximal cycle at 40% maximal power output (WRmax), followed by a V̇O2max test. Hemoglobin (g/L), WRmax (watts), time to fatigue (seconds), heart rate (bpm), oxygen uptake (ml/min·kg), RER and blood lactate response (mmol/L) were measured and compared between conditions. Cardiorespiratory variables were recorded at 5-min intervals and lactate was measured at 10-min intervals during the submaximal exercise. There was a significant 3.4% increase in hemoglobin concentration after spirulina supplementation in comparison to placebo (150.4 ± 9.5 g/L Vs 145.6 ± 9.4 g/L, p = 0.047). No significant differences existed between either condition in both testing protocols for V̇O2max, WRmax, time to fatigue, heart rate, oxygen uptake, RER and blood lactate response (p > 0.05). 14-days of spirulina supplementation significantly improved hemoglobin concentration but did not lead to any considerable ergogenic improvements during maximal or submaximal exercise at a 6 g/day dosage in recreationally active individuals whilst cycling.

Food Technology forecasting: A based bibliometric update in functional chocolates

Technology forecasting (TF) based on bibliometric tools allows knowing the technological trends of developed topics based on experience and current knowledge, thus anticipating future changes. To reduce hunger and improve nutrition, the food-based topic is of central concern, especially functional food. Among these, various studies on chocolates have been performed. On a global scale, these products are at the level of patents, with China leading it, vastly outperforming the cocoa-producing countries. Though no known functional chocolates are sold under that specific name, chocolates on the market serve as "carriers" of bioactive compounds. Unfortunately, they cannot be attributed to health properties since these properties have to be evaluated with in vitro, in vivo, and clinical studies. Launching functional chocolate on the market is possible; however, it would be a long-term process involving previous stages such as studying its ingredients' bioactive properties, laboratory-level product development, functional properties, and quality and acceptance parameters. For research purposes, it is possible to speak of functional chocolates, potentially functional chocolates, or chocolates enriched with bioactive compounds since the development of research does not necessarily involve launching the product on the market.

Antimicrobial activity of Spirulina platensis extract on total mesophilic and psychrophilic bacteria of fresh tilapia fillet

Spirulina platensis has a wide range of activities, notably antibacterial property against food pathogens. This study investigates the antibacterial activity of S. platensis extract on Total Mesophilic and Psychrophilic Aerobic Bacteria. The results were compared using statistical analysis and the predicted model values using artificial intelligence-based models such as artificial neural network (ANN) and adaptive neuro fuzzy inference system (ANFIS) Models. The extraction of spirulina was done by using the freeze-thaw method with a concentration of 0.5, 1 and 5% w/v. Before the application of the extract, initial microbial load of fillets was analyzed the and the results were used as control. After application analysis was performed at 1, 24 and 48 h of storage at 4 °C. Based on the statistical analysis result the S. platensis extracts' antimicrobial activity over TMAB of fresh tilapia fish fillets at 1, 24 and 48 h was using EA from 2.5 log10 CFU/g during the control stage to 1.8, 1.1 and 0.7 log10 CFU/g respectively whereas EB and EC was from 2.1 and 2.2 log10 CFU/g at control to 1.5, 0.8, 0.5 log10 CFU/g and 1.23, 0.6 and 0.32 log10 CFU/g respectively at the specified hour interval. Similarly, the three extracts over TPAB were from 2.8 log10 CFU/g at control time to 2.1, 1.5 and 0.9 in EA, while using EB reduces from 2.8 log10 CFU/g to 1.9, 1.3 and 0.8 log10 CFU/g at 1, 24 and 48 h respectively. Although EC presented the reduction from 1.9 log10 CFU/g to 1.4, 1 and 0.5 log10 CFU/g. This was supported by ANN and ANFIS models prediction.