1

1Introduction of Marine Algae ExtractsKatarzyna Chojnacka and Se-Kwon Kim

1.1Introduction

Recently, there is increased interest in naturally produced active compounds asalternatives to synthetic substances. Although these compounds often show loweractivity, they are nontoxic and do not leave residues. It has already been reflectedby the projects of new law regulations in EU countries that have imposed legalrestrictions on the use of xenobiotics as plant protection products or preserva-tives. In the European Union there are plans of new directives that impose addi-tional environmental taxes, primarily because of the residues of active substancesin the environment. This implies that there is a need to develop new and safeproducts of biological origin, with properties similar to the synthetic, in particularantimicrobial, antifungal, antioxidizing compounds, and colorants. These naturalcompounds are found in algal extracts (Table 1.1).Algal biomass have been used for centuries as food and medicine. The health

promoting effects of algae were discovered as early as 1500 BC [1]. However, thebiomass of algae gained interest as a source of chemicals and pharmaceuticals onlyrecently. Nowadays, the production regime requires the use of extracts rather thanthe biomass itself, because of the formulation requirements (consistency, stabil-ity, color, flavor, etc.). Until now, algal products were available mainly as tablets,capsules, or liquid extracts, and sometimes were incorporated into food products,cosmetics, or products for plants [2]. In 2006, the market of microalgal biomassproduced 5000mg dry biomass/year and generated a turnover of 1.25× 109 USD[2]. The global sector of macroalgae is worth 6 billion USD, with main contribu-tion from hydrocolloids and crop protection products [3]. Recently, compoundsderived from algae (carotenoids, β-carotene astaxanthin, long-chain polyunsatu-rated fatty acids (PUFAs), docosahexaenoic acid) began to be produced on indus-trial scale [4]. Novel compounds isolated from algae possess a great further poten-tial to be applied for their pharmacological and biological activity [4].Seaweeds produce a vast spectrum of secondary metabolites because they

live in nonfriendly environment but are not damaged photodynamically asthey synthesize protective compounds and develop protecting mechanisms

Marine Algae Extracts: Processes, Products, and Applications, First Edition.Edited by Se-Kwon Kim and Katarzyna Chojnacka.© 2015 Wiley-VCH Verlag GmbH & Co. KGaA. Published 2015 by Wiley-VCH Verlag GmbH & Co. KGaA.

2 1 Introduction of Marine Algae Extracts

Table 1.1 Major compounds in algal extracts [2, 11, 19, 20].

Compound Function Application

Polysaccharides Components of cell wall(fucoidan, alginate,laminarin)

Provide strength, flexibility,maintain ionic equilibrium,prevent from desiccation

Phenolics andphlorotannins

Not found in terrestrialplantsPhenol rings in polyphenolsact as electron traps toscavenge radicals

Antimicrobial, antioxidant,antiviral compounds thatprotect the algae from abioticand biotic stress conditions, forexample, phlorotannins thatare formed from oligomericstructures and phloroglucinol

Protein, peptides, andessential amino acids

The contents vary Antioxidative, but difficult toextract

Lipids Polyunsaturated fatty acids(PUFA) (ω-3 andω-6) – higher level than interrestrial plants

Structural membrane lipids;important in human andlivestock diet. Composed ofglycerol, sugars, basesesterified with fatty acids(saturated or unsaturated(C12–C22))

Terpenoids and steroids Carotenoids, xanthophyll,fucoxanthin, astaxanthin

Antioxidant, antiviral,anti-inflammatory activity, UVprotection

Vitamins A, B1, B2, B6, B12, C, E,nicotinate, biotin, folic acid,pantothenic acid. Leveldepends on the season

—

Minerals Se, Zn, Mn, Cu – structuralcomponents ofantioxidative enzymes

—

[5]. Environmental stress to which algae are exposed include rapid fluctua-tions of light intensity, temperature, osmotic stress, desiccation that lead tothe formation of free radicals and oxidizing agents that lead to photodynamicdamage [6].

1.2Algal Biomass as a Useful Resource

Algae are the oldest photosynthetic organisms dating back to 3.8 billion years(prokaryotic cyanophytes) [7]. The number of species is estimated as 280 000 [7].Algal biomass is being used as the raw material for different branches of industry

1.2 Algal Biomass as a Useful Resource 3

and the global production is prevalently increasing [7]. Algae are photosyntheticorganisms that convert light energy from the Sun into chemical energy stored inthe formof chemical compounds in the process of photosynthesis [1]. A character-istic of algae is that they possess a simple reproductive structure [8]. The biomassof algae contains various compounds with diversified structures and functionsthat are synthesized in the response to stress conditions, for example, heat/cold,desiccation, salinity, osmotic stress, anaerobiosis, nitrogen deficiency, photooxi-dation, as protection from physiological stressors [1]. Algae are a diversified groupof organisms and are divided into microalgae and macroalgae. The first groupincludes prokaryotic cyanobacteria and eukaryotic microalgae [9]. Algae are verydiversified organisms when considering size (from unicellular microalgae to mul-ticellularmacroalgae) [10].The basis for the classification of algae is pigmentation:green (Chlorophyceae), red (Rhodophyceae), and brown (Phaeophyceae) [11]. Thedifference concerns not only pigmentation, but also the type of storage materialand the composition of cell wall polysaccharides [12]. Algae are simpler than ter-restrial plants [12]. Algae could be considered as natural factories that producebioactive compounds [13]. The composition of green algae: 10% protein, 35% car-bohydrate, and 50% ash (Ca, Fe, P, Cl) [12].Algae were in use since prehistory as the components of diet and as medicine

[14]. Although the importance of algal industry is permanently increasing, thereare some contradictions between Asian (Far East) and European ways of utiliza-tion of this resource [14]. In Europe, the biomass of seaweeds was treated as a sortof waste from seas and oceans [14]. Certainly, algal biomass is still an underutilizedbiological resource.Algal biotechnology is divided into two branches: microalgal and macroalgal,

with its unique specificity [15]. Microscopic algae are called microalgae; however,this term is not related to taxonomy. Among microalgae, cyanobacteria aredistinguished, which are prokaryotic [15]. Macroalgal biotechnology includes theproduction of (phycocolloids agar-agar, alginates, carrageenan) from Rhodophytaand Phaeophyta, and the global value is 6× 109 per year [15]. At present, the maindirections in macroalgal biotechnology are biofuels, agricultural biostimulantsfor crop plants, probiotics for aquaculture, soil bioremediation, wastewatertreatment, and biomedical applications of extracted compounds (polyphenols,polysaccharides) [3]. Microalgal biotechnology refers to the production ofdifferent products: phycocyanin, carotenoids (β-carotene, astaxanthin), fattyacids and lipids, polysaccharides, immune modulators that find an applicationin health food, cosmetics, feed and food supplements, pharmaceuticals, andfuel production [15]. Microalgal groups of the major importance are cyanobac-teria (Spirulina sp.), Chlorophyta (Chlorella sp., Dunaliella sp.), Rhodophyta(Porphyridium sp.), Bacillariophyta (Odontella sp., Phaeodactylum sp.) [15].While macroalgae are harvested from natural habitats, microalgae are culti-vated in artificial systems [15]. The products of microalgal biotechnology arecoloring substances (astaxanthin, phycocyanin, phycoerythrin), antioxidants(β-carotene, tocopherol, antioxidant CO2 extract), and arachidonic acid (ARA),docosahexaenoic acid (DHA), and PUFA extracts [15].

4 1 Introduction of Marine Algae Extracts

1.3Biologically Active Compounds Extracted from Algae

Because algae are coastal primary producers and have impressive possibilities tosurvive in extreme environmental conditions, in particular to trigger oxidativestress, they produce a variety of useful compounds [16]. Algae live in extremeconditions: fluctuating salinity, temperature, nutrients, and UV–vis irradiation[10]. Long periods of desiccation cause overproduction of reactive oxygen species,which is neutralized by physiological and biological mechanisms: the productionof secondary metabolites [16]. Therefore, compounds isolated from the biomassof seaweeds possess biological activity. The biomass of algae contains many valu-able components: minerals, vitamins (A, B, C, E), PUFAs (ω-3), amino acids, pro-teins, polysaccharides, lipids, and dietary fiber [17]. Many of these bioactive con-stituents can be extracted to obtain antioxidative, anti-inflammatory, antimicro-bial, anticancer, antihypertensive products [11, 17]. Particularly useful are sec-ondary metabolites with antiviral, antimalarial, anticancer properties [1]. Prod-ucts derived from algae also contain polysaccharides, polyphenolic compounds,and terpenes [11]. Seaweeds and their extracts are added to food as antioxidants,antimicrobials, dietary fiber, and dietary iodine [6].In various studies, strong antioxidative properties of compounds isolated from

seaweeds were confirmed [18]. Antioxidative activity produces phlorotannins(polyphenolic compounds – 1–10% d.m. of brown seaweeds), alkaloids, terpenes,ascorbic acid, tocopherols, and carotenoids [18]. Antioxidants transform radicalsinto nonradicals by donating electrons and hydrogen, chelation of transitionmetals, and dissolving peroxidation compounds [6]. The role of antioxidants isto prevent lipid oxidation, inhibiting the formation of products as a result ofoxidation, and consequently prolonging the shelf life of products [6]. Algae are arich source of natural antioxidants and antimicrobial compounds [6].The research on the composition of algal extracts concerns mainly antioxidants

as an alternative to synthetic, because according to recent research these com-pounds if used as food additives are potential promoters of carcinogenesis [1].Theextracts modulate the oxidative stress and diseases related to radical scavengingeffect: sesquiterpenoids and flavonoids (green alga Ulva lactuca), phlorotannins(brown alga Eisenia bicyclis, Ecklonia cava, E. kurome), phycobiliprotein, and phy-cocyanin (blue-green alga Spirulina platensis), which protect from DNA damageby H2O2 [17].

• Anti-HIV – cyanovirin – protein from Nostoc ellipsosporum [1]• Photoprotective compounds – repair DNA damage – mycosporine-like aminoacids, scytonemin enzymes (shock proteins) – superoxide dismutase, catalase,and peroxidase [1].

Microalgae contain carotenoids, PUFAs, phycobilins, sterols, polyhydrox-yalkonates, and polysaccharides [9]. They can be considered as cosmeceuticals,nutraceuticals, and functional foods [9]. For instance, Spirulina contains lipids

1.4 The Application of Products Derived from Algal Biomass 5

(6–13; 50% in the form of fatty acids), phycocyanin (20–28%), and carbohydrates(15–20%; mainly as polysaccharides) [21].Algal cells contain phytochelatins – proteins synthesized in response to expo-

sure to toxic metal ions [22]. However, the attempt to extract and use these pro-teins is not found in the available literature [22].

1.4The Application of Products Derived from Algal Biomass

The global wild stocks of seaweeds yield 8 million mg of biomass [18]. In 2004,the contribution in the market was as follows: sea vegetables (88%), phycocol-loids (11%), phycosupplements (1%), and the minor contribution of soil additives,agrochemicals, and animal feeds (totally, 6000 million USD) [14]. Algal extractscreate a new market sector, because they can be used in a variety of products,for example, antioxidant capsules containing Spirulina extract, Chlorella extractin health drinks, oral capsules containing carotenoid extracts from Dunaliella[15]. Other examples of algal extracts-based products are pet functional food,biofertilizers (which increase water-binding capacity and serve as the source ofminerals and substances promoting germination, growth of leaves and stems andflowering).Of particular interest are antioxidants present in algae and their extracts, as

the use of synthetic antioxidants has been restricted because of toxicity andhealth risks [23]. It is important to replace these synthetic compounds withnatural antioxidants [23]. Antioxidative compounds from marine sources includevarious functional compounds, for example, tocopherols [19]. Lipid-soluble algalextracts can be used as protective functional ingredients [19]. Antioxidativeproperties of natural compounds from algae can prolong the shelf life of foodsand cosmetics through delayed oxidation [11]. Natural anti-oxidants may alsobe useful in treating aging, UV-exposure, and diseases associated with oxidation[11]. Extracts from algae are used in cosmetics, for example, from Spirulina andChlorella [2].Polysaccharides isolated from algae are other important components of foods

and cosmetics and in nutraceutical and pharmaceutical preparations and are pro-duced mainly from seaweeds [21]. Polysaccharides (carrageenans, alginates) areused in food industry as edible packaging materials [6].The main source of industrially exploited polysaccharides (alginate, agar, car-

rageenan) originates from the biomass of algae [12]. Algal biomass contains signif-icantly higher levels of polysaccharides than terrestrial plants [12]. Algal polysac-charides differ from those in terrestrial plants: sulfate groups, additional sugarresidues, high content of ionic groups, high solubility in water, and unique rheo-logical properties [12].Polysaccharide production includes the following steps: selection of raw mate-

rial, stabilization and grinding of biomass, extraction and purification, precipita-tion, and drying [12].

6 1 Introduction of Marine Algae Extracts

1.4.1Agriculture – For Plants

In modern agriculture, higher production should accompany lower environmen-tal impact and higher sustainability [24]. These criteria fulfill biostimulants thatimprove efficiency of regular fertilization (increase the efficiency of nutrientsuptake), enhance yield and the quality of crops, improve tolerance to environ-mental stress, and possess antioxidant properties [24]. Biostimulants are naturalsubstances that promote growth, uptake of nutrients, and tolerance to abioticstress and different climatic conditions [25]. Seaweed extracts can be used asfoliar sprays for vegetables, grains, and flowers [24]. Plant growth regulators aredefined as bioactive compounds. It is desired that they perform well and aredegraded into products that are not harmful to the environment [26].European Biostimulant Industry Council (EBIC) was established to help intro-

duce agriculture biostimulants to the market and support regulatory EU author-ities to describe biostimulants as innovative class of products, the production ofwhich uses minimal synthetic processing. Biostimulants are approved in organiccrops, with an important group of products derived from macroalgae [27].Seaweeds have been used in the cultivation of plants since antiquity [28].

Seaweeds were composted since antiquity and used as soil amendments. Thefirst industrial applications of seaweeds in agriculture were in 1944, as the newsource of fiber [14]. At present, the extracts are applied directly to shoots foliarlyor to soil [3]. The examples of algal extracts currently available on the market areKelpak, Actiwave, and AlgaGreen [3]. Seaweed concentrates (e.g., Kelpak) areapplied at low rates and have growth promoting effect following the presenceof plant growth regulators (e.g., cytokinins and auxins, polyamines, putrescine,spermine) rather than nutrients [29].These active substances increase the growthof nutrient-stressed plants [29].In 1949, the product Maxicrop was developed [14]. Using liquid seaweed

is advantageous, because plants respond immediately and positively (dilution1 : 500); also, the ions of micronutrients (Cu, Co, Mn, Fe) are soluble at highpH and are chelated by partly hydrolyzed sulfated polysaccharides; soil crumbstructure is improved (with alginate and fucoidan), microorganisms, root system,and plant growth are stimulated [14].Extracts from seaweeds are useful in the cultivation of plants because they

improve a wide range of physiological responses: increase crop yield, improvegrowth, improve plants’ resistance to frost, serve as biofungicide and bioinsec-ticide, increase nutrients’ uptake from soil because they contain plant growthregulators [30]. The extracts are used in low doses (high dilutions), because theactive substances are efficient even in small quantities [30].The compounds found in algal extracts that are important for plant growth are

cytokinins, auxins, abscisic acid, vitamins, amino acids, and nutrients [24]. Theoutcome is the result of the synergistic effect of many compounds present in algalextracts [24]: phytohormones, betaines (organic osmolytes), polymers, nutrients,and alginic acid (soil conditioning agent that supports soil structure) [25, 28].

1.4 The Application of Products Derived from Algal Biomass 7

There are various reports of laboratory, pot, and field studies that aimed totest the plant growth stimulating properties of algal extracts. El-Baky et al. [31]investigated the effect of treatments with microalgae extracts (Spirulina maximaand Chlorella ellipsoida) on antioxidative properties in grains of wheat. The con-tent of carotenoid, tocopherol, phenolic, and protein in grain was investigated.Antioxidant activity of ethanolic extracts showed the significant increase of radi-cal scavenging activity in response to microalgal extracts treatment [31].

1.4.2Functional Food

Functional food is defined as food that positively affects one or more physiolog-ical functions to increase the well-being and reduce the risk of suffering for dis-eases [8]. Recently, a new market for functional food has evolved, the food called“food for the not-so-healthy” [13]. Functional food is produced by the addition ofactive components. Functional food contains functional ingredients: micronutri-ents ω-3 fatty acids, linoleic acids, phytosterols, soluble fiber (inulin – prebiotics),probiotics, carotenoids, polyphenols, vitamins that present healthy effect on theorganism [13]. New, biologically active natural ingredients (antioxidant, antiviral,antihypertensive) extracted from the biomass of algae are becoming importantresearch objects in the area of food science and technology [10].Algal extracts are the components of functional food, because they are consid-

ered as natural, biologically active components.The latter, beside nutrition, shouldhave the beneficial influence on functions of the body by improving health or pre-venting from diseases [32]. Extracts from Spirulina can be added to functionalfoods because of antioxidant, antimicrobial, anti-inflammatory, antiviral, and anti-tumoral properties of the compounds (phycocyanins, carotenoids, phenolic acids,and ω-3 and six PUFAs) [32].Algae are used as dietary supplements that are classified into three groups: (i)

Spirulina platensis, (ii) Aph. flos-aquae, and (iii) Chlorella pyrenoidosa [33]. Thebiomass of these microalgae is obtained either from lakes or by cultivation in arti-ficial ponds [33]. Algae can be cultivated, in which the growth rate is high and insome cases there is a possibility of controlling the production of active compoundsby adjusting cultivation conditions [10].The potential use of brown seaweed extracts to inhibit the growth of microor-

ganisms responsible for food spoilage and pathogenic microorganisms was alsoinvestigated [5].The addition of 6% of the extract substantially reduced the growthof nondesired microflora [5].

1.4.3Cosmetics

Microalgae, the biomass of which is to be used as the raw material for isolation ofbeneficial compounds, are cultivated in artificial systems that provide the biomassthat is free of impurities [7]. Algal extracts are useful in the skin care market as

8 1 Introduction of Marine Algae Extracts

well because they support regeneration of tissues and reduce wrinkles, in partic-ular, the extracts from Spirulina (which repair signs of aging, prevent stria forma-tion) and Chlorella (stimulate collagen synthesis) [2].The properties of microalgalextracts include reduction of intracellular oxidative stress and synthesis ofcollagen [7].Extracts from the followingmicroalgae are produced commercially for cosmetic

industry [7]:

• Nannochloropsis oculata – vitamin B12, vitamin C, and antioxidants• Dunaliella salina – pigment industry (carotenes), amino acids, and polyphe-nols

• Chlorella vulgaris – proteins, and inorganics substances.

1.4.4Pharmaceuticals

Algal extracts can replace commercial antibiotics in disease treatments [34].Biologically active metabolites isolated frommarine algae have the potential to beused as pharmaceuticals because they inhibit the growth of bacteria, viruses, andfungi [34]. The chemicals are macrolides, cyclic peptides, proteins, polyketides,sesquiterpenes, terpenes, and fatty acids [34]. Cavallo et al. [34] investigated theeffect of lipid extracts from six algae and their antibacterial activity against fishpathogens and found that they can be used as antibacterial, health promotingfeed for aquaculture.Extracts from Spirulina are active against viruses (herpes, influenza,

cytomegalovirus) and inhibit carcinogenesis [35]. Spirulina is the source ofvitamin A that is highly absorbable [36].Hot water extract from Spirulina supports human immune system by the

improvement of immune markers in blood (higher level of gamma interferon andinterleukin-12p40 and toll-like receptors) and acts directly on myeloid lineagesand natural killer-cells (NK cells) [35]. Immulina is a polysaccharide found inthe extract from Spirulina that activates monocytes. Water extracts also showedantiviral activity [35].

1.4.5Fuels

Seaweed extracts can be the resource to produce liquid fuels (ethanol), because ofhigh carbohydrates (laminaran, mannitol) content [37]. Seaweeds can be biocon-verted to methane [37].

1.4.6Antifouling Compounds

Extracts from marine algae (e.g., Enteromorpha prolifera) contain compoundsthat have antifouling properties toward, for example, mussels (Mytilus edulis) and

1.5 Extraction Technology 9

larval settlement: tannins (Sargassum natans), bromophenol (Rhodomela larix),diterpenes (Dictyota menstrualis), and halogenated furanones (Delisea pulchra).These compounds have the potential in the prevention from fouling of ship hullsand aquaculture nets instead of organotin or paints based on toxic metals [38].

1.5Extraction Technology

Seaweed industry was established in 1950s [3]. The production concerned mainlylow-cost fertilizers and food [3]. For the first time liquefaction of seaweeds wasundertaken in 1857 by compressing [28]. The goal was to obtain the formulationthat is transportable over long distances [28]. Algal extracts were obtained andpatented in 1952 by alkaline extraction [3]. Another process was milling in lowtemperature [28].Although natural extracts possess a great applicable potential, the problemwith

natural products is variable composition of extracts because of fluctuations in theraw material (season, location), different extraction techniques [12]. Extractionmethods vary and the following can be distinguished: ethanol, methanol, enzy-matic [17], composting, supercritical CO2 extraction with cosolvents.In the elaboration of a new extraction technology, it is necessary to select the

target bioactive compound, select the species of alga for extraction containingthe compound of interest, select the operation conditions to find a compromisebetween the yield and purity, and consider if large enough resources of the algaeare available.It is essential to develop appropriate, quick, cost-efficient, and environmentally

friendly methods of extraction that aim to isolate biologically active compoundsof interest [10] without loss of their activity. It is essential to develop extractionprocedures that involve the use of specific solvents and processes [8].The production of algal extracts consists of several unit operations [7]:

• Upstream processing – preparation for cultivation• Cultivation – in photobioreactors• Downstream processing – cell harvesting, rehydration and hot water extrac-tion, centrifugation, and ultrafiltration

• Formulation, preservation, and conditioning.

Traditional extraction techniques (soxhlet) solid–liquid extraction (SLE),liquid–liquid extraction (LLE) consume large quantities of solvents and requirehigh extraction times [8]. These procedures present low yield of extraction andlow selectivity toward bioactive compounds [8]. Because of the lack of automa-tion, reproducibility is low [8]. Recently developed techniques supercriticalfluid extraction (SFE), pressurized liquid extraction (PLE), accelerated solventextraction (ASE), pressurized hot water extraction (PHWE), ultrasound-assistedextraction (UAE), microwave-assisted extraction (MAE) have further reducedthese limitations [8]:

10 1 Introduction of Marine Algae Extracts

• Solvent extraction – large quantities of toxic organic solvents are used, long timeof extraction, laborious, low selectivity, low extraction yields, and not mild con-ditions (temperature, light, oxygen) [32].

• Pressure liquid extraction – less solvent, shorter time of extraction, automated,no oxygen, and no light [32].

• Supercritical fluid extraction – technique used to isolate active componentsfrom natural materials [32].

SFE uses solvents at temperatures and pressures above their critical point and isused to extract compounds from biomasses [8]. In this technique, the consump-tion of toxic organic solvents is reduced and the main solvent used is CO2 [8].The disadvantage is low polarity of CO2 and resulting necessity of the use of polarmodifiers or cosolvents [8]. Advantages are high diffusivity, easiness in the controlof temperature and pressure (possibility of modification of solvent strength), andobtaining solvent-free extracts [8].Extraction of biologically active compounds from algal biomass is not selective.

The extract is a mixture of different compounds [11]. The factors that influencethe composition and thus the activity of algal extracts depend on species, environ-mental conditions, season of the year, age, geographical location, and processingtechnologies [11]. For instance, ethanol was found to be more efficient in theextraction of polyphenols than water [23]. Seaweed extracts contain PUFAs (inparticular ω-3 long chain PUFA) that have several health promoting effects andhave the potential to be useful in treatment or reducing symptoms of: cardiovas-cular disease, depression, rheumatoid arthritis, and cancer [19].Chaiklahan et al. [21] optimized the extraction of polysaccharides from

Spirulina sp. It was found that the mostly significant operation conditions weretemperature and solid to liquid ratio and time. The extract contains rhamnoseand phenolic content [21].Seaweed concentrates are used as supplementary soil conditioners that promote

plant growth and improve crop yield [29]. An example product is Kelpak® fromEcklonia maxima [29]. These products are used in very low doses and contain,for example, cytokinins and auxins that are plant growth regulators [29]. Seaweedextracts are particularly useful if applied on plants that are nutrient-stressed [29].

1.6Conclusions

Algae are a useful raw material for biobased economy, because their cells containa vast array of useful compounds with high biological activity. Biomass of algaeis certainly an underestimated resource. In the process of extraction it is possibleto draw the valuable compounds closed in the algal cells. However, this should becarried out in such a way that the structure and thus the properties of the com-pounds are not destroyed and that the solvent used does not limit their use as safecomponents of products for plants, animals, and human.

References 11

There aremany ways to implement the extraction process and this is thoroughlydiscussed in this book. In addition to developing extraction technology, it is veryimportant to assess the utilitarian values of the extracts, which can be documentedin application studies of extracts in real systems.Preparation of algal extracts represents a new approach in the preparation of

natural products with a standardized composition, as compared with the biomassitself and certainly will be a future for algal industry.

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12 1 Introduction of Marine Algae Extracts

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