Algal Functional Foods and Nutraceuticals: Benefits, Opportunities, and Challenges

The use of algae as food by humans started in pre-recorded history and is most widespread in Asia, where algae are used as part of the peoples’ daily diet. Of more than ten thousand species of algae that have been described taxonomically, only about a hundred species are known to be edible and are generally recognized as safe (GRAS). Algae for human consumption come from both natural population and opensea aquaculture, but with increasing issues of marine pollution, global warming and marine use conflict, the production of some algal species from aquaculture is shifting towards the more controlled condition of land-based production systems or in sea areas far from sources of pollutants. The preparation of edible algae comes in various forms that are either consumed directly as fresh salad or pickled in vinegar for species with foliose, delicate or succulent nature or as blanched or cooked recipes for species with fleshy, rubbery or firm texture, or they are consumed indirectly as an ingredient or additive of some food recipes as gelling, hardening, or thickening agent. Many species of micro- and macroalgae have nutritional profiles that make them a perfect food for individuals who are on a diet or are health conscious. This chapter describes some of the most common algal genera whose biomass is mainly produced from culture systems that involve a land-based culture facility (e.g., photobioreactor) and or seedling collection procedure prior to open sea cultivation.

Microalgae are unicellular autotrophic and heterotrophic microorganisms that can exceed the areal productivity of land plants by order of magnitude. Microalgae are producers of food, medicines, high-value bioactive substances and biofuels. They are highly adaptable, allowing them to thrive in freshwater and saltwater, and can be cultivated on non-arable land. Different cultivation methods have varying effects on the yield of bioactive substances produced by microalgae. As such, selecting the appropriate cultivation conditions is imperative for efficient compound production. This chapter summarizes the current state of microalgae cultivation, techniques for overproduction of high-value nutraceuticals, and future prospects, with the aim of providing the reader with fresh ideas for the cultivation of microalgae for human health.

The demand for nutrient-rich foods is steadily rising. Algal foods have gained a lot of attention lately because of their health benefits and nutritional worth. To overcome the challenges caused by environmental, seasonal, and nutritional changes, algae use a variety of routes and create a variety of phytochemicals. The combination of macro and micro nutrients also changes, which can result in the development of hazardous metabolites in some cases. Proteins, polysaccharides, lipids, and vitamins are the key components produced by algae. Similarly, because of their superior nutritional value, many microalgae are used as a whole-cell food source. The environmental influence on the production of these macronutrients and species employed as functional foods will be discussed in this chapter.

Seaweeds are primary producers of the oceanic ecosystem and essential for the survival of marine life forms. As they proliferate and restructure niches, they support the development, reproduction, and growth of a plethora of marine biodiversity habitats. However, the unprecedented climate change and human interventions have severely compromised coastal ecosystems. The physiological parameters such as temperature, pH, and carbonate chemistry have affected the abundance, nutritional dynamics, and, most critically, the geospatial distributions of seaweed communities. These factors play a pivotal role in the design and establishment of artificial cultivation strategies for economically valuable seaweeds. So far, the meager explorations of geochemical interactions among seaweeds have made it difficult to understand the possible environmental interactions with seaweed communities, thus sometimes severely affecting commercial cultivation practices. Furthermore, modeling environmental parameters with coastal geochemistry may effectively address the management and conservation of seaweed biodiversity.

Today, consumers pay more attention to natural therapies rather than pharmaceutical treatments. Contentedly, algal nutraceuticals provide a massive range of medicinal properties. Both macro and microalgae have shown health beneficial bioactivities like antioxidant activity, antidiabetic, anti-inflammatory, anticancer, antitumor activities, etc. When evaluating algal nutraceuticals in the global market, several weaknesses can be identified with regard to their food safety and quality. The lack of standards and legislation on handling seaweeds in the food industry is a hindrance to enjoy the actual health benefits of algal nutraceuticals. Trends in microalgal nutraceuticals have increased since they can be cultivated easily in the natural environment. The capacity of biological activities of algae in the human body as nutraceuticals and pharmaceuticals is higher than some terrestrial plants and animal sources. Therefore, bioactive compounds of algae will definitely help to prevent infectious pandemic diseases like COVID-19. Algal proteins also have emerged as a meat alternative. Research studies on the bioavailability and digestibility of these bioactive constituents are found to be still limited. Therefore, consumers show less tendency to consume algal nutraceuticals. Anti-nutritional factors like fiber, tannin and certain cations reduce the bioavailability and digestibility of algal nutrients. However, new technologies are now being developed to reduce these limiting factors. Today, with the influence of the green technology concept, algae will perform a great role in human health as a promising source of nutraceuticals.

Among various emerging food sectors, the nutraceutical sector has gained the attraction of most industries and researchers. Nutraceuticals are generally considered to be the alternative to the pharmaceutical dosage which provides physiological benefits. They are usually functional ingredient present which supplements nutrition to the body. These nutraceuticals are also derived from algae, where the most commonly found products of algae are derived from Spirulina sp, Chlorella sp and Klamath sp. It is reported that microalgae tend to strengthen the immune system by increasing nutritional constituents present in the body. In this review, detailed elaboration of various nutraceutical compounds from algal sources, their recent trends and future prospects are discussed.

Algal bioactive compounds, including pigments, polyunsaturated fatty acids, vitamins, proteins and phenolic compounds, have a wide range of increasing applications in the pharmaceutical, nutraceutical, feed, food, and cosmetics sectors. Extraction of such compounds with the purpose of obtaining nutraceutical and food ingredients at large has been under scrutiny over the last years towards greener and more sustainable bio-based processes. The step of the extraction is indeed considered the most expensive in algal-based industrial bioprocess, mainly owing to the high processing costs and environmental impacts. Therefore, the application of a biorefinery strategy (for biomass reutilization, via choice of specific green and generally recognized as safe solvent), will certainly help attain a more feasible and competitive solution. Furthermore, emerging extraction technologies are potentially suitable for application at a large scale, as part of a multi-integrated extraction strategy. This chapter accordingly addresses the most important (micro)algal-compounds possessing bioactivities, and already or likely to be used as functional ingredients; in addition, extraction procedures thereof are discussed, bearing in mind a biorefinery strategy – with major prospects and associated challenges.

Algae are ancient oxygen-producing photosynthetic organism that lives in water bodies all over the world. The algal biodiversity in the aquatic ecosystem represents a new field of product discovery with the potential to manage human ailments. They are untapped resources, and in recent years, algal culture technology has been a business-oriented field owing to its diverse applications. The consumption of algae is traditional in human diets and dates back thousand years ago. The recent increasing algal demand is due to its safety and functional benefits. Algae are an edible source of food with potential therapeutic activities of anti-oxidant, antiobesity, antidiabetic, anti-inflammatory, anti-cancer, anti-viral, antifungal, and antibacterial properties, which could be employed as medical ailments. Different types of algalderived bioactive compounds in a biological system are evidenced by in vitro and in vivo examinations. Raw algae or its compound are under a pipeline of market production due to their cultivable nature, which actually paves the way to generate larger business in the food and nutraceutical industry. This chapter summarizes several algal bioactive compounds with proven activities against metabolic disorders.

Edible seaweeds (macroalgae and microalgae) are considered superfoods of our waterways. Based on pigmentation seaweeds, macroalgae are classified into three groups, green seaweeds (Chlorophyta), brown seaweeds (Phaeophyta) and red seaweeds (Rhodophyta). Seaweeds are rich in macro and micro nutrients. They contain protein, dietary fiber, minerals, vitamins, polyphenols, peptides, sterols and polyunsaturated fatty acids. Apart from being a major nutritional source in the human diet, seaweed is considered a functional and nutraceutical due to its extra nutritional and physiological properties. Plethora of bioactive compounds with potential applications in food, medicinal, health and pharmaceutical industries are included in extensive research and industries. For example, phycocolloids from seaweeds are widely used in the food industry. Medicinal and pharmaceutical properties of edible seaweeds include anti-tumor property, anti-viral property, anti-coagulant property, anti-Alzheimer’s property, and anti-oxidant property. Thus, a vast scope of investigating and understanding bioactive compounds from edible seaweeds is welltimed.

As global populations increase, sustainable food production has become concerning, with a massive proportion of the population suffering from malnutrition, and the gradual worsening of negative environmental impacts. Microalgae offer an alternative to traditional food sources, being able to meet nutritional requirements while not competing for arable land, using large amounts of water, or polluting the atmosphere. Algae can be used to produce key nutrients of the human diet – aminoacid- rich protein and healthy fats and oils, the benefits of which have been clearly documented previously. Mass cultivation of algae as a food product would be a step in the correct direction for sustainable food production and can provide significant improvements over traditional agriculture and crop farming industries in terms of health and sustainability.

Micro-algae are a rich natural source of highly valuable bioactive compounds like mycosporine-like amino acids (MAAs), scytonemin, carotenoids, vitamins, essential amino acids (EAAs), polyunsaturated fatty acids (PUFAs), minerals, polysaccharides, lectins, halogenated compounds, polyketides, agar-agar, alginic acid, carrageenan, enzymes and fibers. These compounds are involved in several defense strategies helping organisms to survive in various extreme environmental conditions, such as high salinity, high and low temperatures and deleterious solar radiation. Furthermore, they are promising biocatalysts and can be used in the field of “white biotechnology” to improve the sustainable production of metabolites. Micro-algae have the potential to become one of the most promising and innovative sources for novel food and functional products. They play a major role as functional ingredients for the enhancement of the nutritional value of foods and thus improving human health, wellbeing and quality of life. Micro-algal-derived bioactive compounds have UVscreening, anti-inflammatory, anti-microbial, antioxidant, antibiotics, immunosuppressants, anticancer and antiviral properties. These bioactive compounds have many biotechnological, industrial, pharmaceutical and cosmetic uses that are discussed in this chapter with their emerging techniques of harvesting to enhance their production on a commercial scale. The diverse metabolites from indigenous sources facilitate the promising effect, enabling researchers and pharmaceutical companies for the production of novel non-toxic and cost-effective medicines related to various applicable fields.

Algae, formerly used in food in countries on the Asian continent, are increasingly common in Western countries. These are foods with great nutritional value due to their composition in minerals and vitamins, as well as bioactive substances. Seaweed is a valuable source of antioxidants that, with its consumption, would help reduce oxidative stress. Likewise, it should be noted that the production of algae is sustainable and that, due to its own growth factors and low requirements, it reduces economic costs. This chapter will study the nutritional properties of the consumption of edible algae and the possible differences between edible species of algae and its contribution to the recommended daily requirements.

The well-being and improvement of an individual’s health, is directly linked to food. Acknowledging the well-studied interrelation between health and nutritional food determines the need to cultivate, maintain and advance a novel branch of food science, known as functional foods. Research interest has extensively increased in the last three decades for the exploitation of seaweeds as functional foods or as nutraceuticals, which provide health and dietary benefits beyond their nutritional content. Additionally, seaweeds have been studied for their metabolites which exhibit biological activity, to manufacture therapeutically superior products. This chapter focuses on providing information related to omics-based seaweed metabolite identification and their applications in human health as a food ingredient

The aim of this work is to explain the probiotic activity of algae and the role of their bioactive compounds as a dietary supplement for promoting growth and disease resistance. Micro- and macroalgae are good alternatives to chemical probiotics because they contain important and safe functional components such as polysaccharides, fatty acids, pigment and proteins, which are considered an extraordinary source of prebiotics with health benefits and enhance healthy colonic microbiota composition. Recently, algae and their extracts have been employed in ingestion systems, simulating the human colon, or animal models. Especially, macroalgae and their polysaccharides have been used for decades to improve human health depending on saccharolytic fermentation by the gut microbiota. Generally, the addition of algae leads to enhance the viability of probiotic bacteria, the acidity of food, and storage quality and, consequently, prevent certain human diseases. Therefore, further investigations should be done for screening and identifying putative prebiotic compounds from algae via the host organism's identification, which utilizes algal bioactive metabolites produced. There will be a need for increasing algae production to replace or supplement the intake of plant foods of terrestrial origin.

For decades, it has been evidenced that seaweeds are used as part of the human diet in many parts of the world. Across the globe, it has been investigated and accepted that seaweeds are rich source of diverse bioactive compounds and can be used as functional foods. These bioactive compounds or metabolites are derived in the form of peptides, polysaccharides, fatty acids, pigments and polyphenols. They have various bioactive properties like anti-cancerous, anti-inflammatory, antibacterial, antioxidants and anti-diabetic. Further, these findings were noticed by pharmaceutical industries that seaweeds can be employed as nutraceuticals for various human ailments. Environmental factors contribute to maximum diversification in the production of metabolites; therefore, there is a need to develop a better understanding of the functional importance of novel metabolites through screening. Several modern analytical tools have been used to elucidate the functionality and characterisation of the metabolic network. This study of metabolic network regulation forms the newly emerging field regarded as metabolomics. This chapter highlights various types of metabolites in seaweeds as phyco-nutraceuticals. Also, various techniques have been discussed to characterize and profile seaweed-derived metabolites. The chapter also emphasises the seaweed-derived bioactive compounds' potential and economic importance

Algae establish a dissimilar group owning huge morphological and metabolic variety. Algae are an exclusive source of beneficial constituents, holding exciting biological activity. They consist of several groups, including unicellular, colonial or filamentous, photosynthetic or heterotrophic micro-organisms containing chlorophyll and other pigments. The photosynthetic pigment composition of algae depends on the quantity and quality of light received by them. In addition to chlorophyll, algal cells comprise a numeral of accessory pigments, such as phycobiliproteins and carotenoids, that aid in photosynthesis and guard the cells against photo blanching. Pigments are light-absorbing molecules in algae. The conventional botanists categorize the algae based on their colour, more specifically based on the distribution of the pigments, which has great taxonomic significance in algal systematics. More than 40,000 algal species have been classified under prokaryotic algae (cyanobacteria) and several eukaryotes, including green algae, diatoms, yellowgreen algae, golden algae, red algae, brown algae, dinoflagellates and others. These intense metabolites from algae have numerous biotechnological and industrial applications in cosmetic, food, diagnostic and pharmacological industries owing to their nontoxic, noncarcinogenic environment and additional health-promoting properties like antioxidative and immune-boosting effects. Cumulative trials of clinical research on health aids of algal metabolites and pigments have made them a harmless and viable replacement for chemically synthesized drugs. Additional perception into the biological properties of these molecules and their method of action will aid in the improvement of effective pharmaceutical products. 

Seaweeds are an abundant source of bioactive compounds and hydrocolloids that can be used in several industries, especially in the food industry. They can be directly consumed as a whole, used as an ingredient, or a source of several compounds that can enrich the nutrient content and sensory experience of foods. The demand for more sustainable packaging options resulted in the increase in research and development of edible seaweed-based films that ensure the safety and quality of the food products, while reducing packaging waste. This chapter will make an overview of the seaweed compounds used in the food industry, their use in the formulation of edible active packaging, and how this packaging can become widely available for consumers.

Accumulation of non-biodegradable plastics is causing high levels of environmental pollution. Currently, edible and biodegradable films and coatings for food and nutraceutical applications are a fast emerging technology with increased attention among researchers and consumers, which acts as an alternative to these synthetic plastics. Edible coatings are most commonly developed from polysaccharides and proteins. Among polysaccharides, seaweed-based polysaccharides play a vital role. These seaweed-based polysaccharides, which are utilized in the development of edible coatings and films, include Agar, Alginate, and carrageenan. Alginates are extracted from brown algae, while agar and carrageenan are extracted from red algae varieties. These developed coatings and films are commonly applied to extend the shelf life and maintain the desired quality level in food. These films or coatings can be applied to foods such as fruits, vegetables, meat, poultry, seafood, and dairy products. They improve the quality of the product by retarding moisture loss, reducing lipid oxidation and discoloration, sealing in volatile flavors, and functioning as carriers of food additives such as antimicrobial and antioxidant agents. This book chapter discusses the application of seaweed-based biodegradable films and coatings for food and nutraceuticals.

The use of biopolymers instead of synthetic polymers for food packaging has become a recent trend since it successfully solves the global issue of plastic waste due to their biodegradability, biocompatibility and renewability. Moreover, edible packaging has gained the attention of the current research world. Thus, the natural polymer sources applicable in forming edible packaging materials, such as polysaccharides, proteins and lipids, are studied. Seaweed, referred to as marine macroalgae, is a rich source of polysaccharides. Different types of polysaccharides can be identified in the three main varieties of seaweed, carrageenan and agar in red algae, alginate, laminaran and fucoidan in brown algae, while ulvan is the major polysaccharide in green algae. The film-forming properties of these seaweed-based polysaccharides are enhanced due to their colloidal nature; meanwhile, the abundance and the low cost make them more applicable in edible packaging. Several modifications were carried out to achieve packaging materials with better mechanical and barrier properties. Hence, this chapter discusses the current applications of seaweed-based polysaccharides in edible packaging with improved properties in different sections such as fruits, vegetables and meat industries by analyzing recent research findings.

Since ancient times, algae have been a staple in the diet of Asian countries. Currently, due to migratory currents, globalization and new eating habits, algae are increasingly common in the markets and shops of Western countries. Edible algae can accumulate elements that, in high quantities, pose a toxic risk to consumers. Various authors have recorded high concentrations of toxic metals and trace elements in edible algae. However, in all cases, it has been shown that some species of algae, such as the Hizikia fusiform alga, tend to accumulate high concentrations of inorganic arsenic, making it necessary to modulate its consumption. Likewise, algae of some geographical origins are more exposed to contamination; therefore, it is recommended to avoid their consumption. Likewise, in cases of people with a susceptibility to suffering from thyroid problems, it is recommended to consume smaller amounts of algae, avoiding some species, such as some species of red algae, which can accumulate higher concentrations of iodine. In conclusion, it is recommended that the consumer varies between species, avoiding consuming a single species of algae, as well as avoiding those algae that come from places with a higher degree of contamination, as it has been shown that they are accumulators of toxic elements. Likewise, it is necessary to monitor the levels of certain toxic elements in edible algae in order to ensure the quality of these foods.