SPIRULINA: A SPOTLIGHT ON ITS NUTRACEUTICAL PROPERTIES AND FOOD PROCESSING APPLICATIONS

for combating Protein Energy Malnutrition (PEM) and Protein Energy Wasting (PEW). Researchers conclude that Spirulina is a genuine health food for children as it was studied to curb bad appetite, night sweats, diarrhoea, constipation

2. As a supplementary food: The protein malnutrition in the 1960's addressed by the FAO led to the identification of spirulina as a supplement for combating malnutrition. 3. As a space food: It was proposed by NASA and European space energy as potential space food that can be consumed during long stays in space (Campanella et al., 1999).

Natural method of cultivation
Spirulina grows naturally in the lakes of the warm regions in alkaline water lakes. It is also a dietary supplement for people living near the lakes of alkaline water etc (Campanella et al., 1999). Spirulina can be cultivated commercially from natural sources. Spirulina maxima is harvested from a lake at 2200m above sea level where the environment is semi-tropical and the temperature on average annually is 18ºC. The algal biomass is filtered, homogenized, pasteurization, and spray dried. In the summer, during the blooming season, spirulina forms thick mats on the lake. It is collected by people in boats of dense concentration in buckets and it is harvested in filters inclined parallel, washed with fresh water, water is removed and pressed again. This paste is extruded into noodle-like filaments which are sun-dried on sheets that are transparent made of plastic. These sun-dried chips are taken to a pharmaceutical factory and pressed into tablets (Ahsan et al., 2008).

The collected spirulina are processed in the following ways
The spirulina that is collected is screened and checked for pond debris, and microscopic algae that give thickened spirulina finally, the water obtained is recycled to the pond. The spirulina droplets are spray-dried and vacuumed into a hopper in the packaging room for collection, which preserves nutrients, pigments, and enzymes that are sensitive to heat (phycocyanin content). Spirulina powder is compressed directly into tablets and sealed in both glass and plastic bottles (Henrikson, 2010).

Commercial method for the production of spirulina
Commercial production of spirulina involves 4 stages. They are culturing, harvesting, drying, and packaging. All these steps have an impact on the final yield and/or product quality. Therefore, careful, and regular monitoring of these processes is crucial for the profitable production of high-quality spirulina that complies with the very stringent quality and safety standards of the food and supplement industries. A closed-loop system is used in the production process, with constant material recycling and evaporation as the only material loss. Throughout the entire production season, the growing medium is recycled. Each pond is collected to the extent that it has grown over the past 24 hours in a semicontinuous culture method. To maximise growth and provide traceability of the manufacturing lot in the event of a problem, the medium is recycled back into the original pond. A regular supply of make-up nutrients is given to restore the harvested algae's absorption. To ensure consistency and ideal circumstances, laboratory scientists do daily tests and monitor and modify nutrients. Every day, ponds are harvested. A stainless-steel screen is used to clean and concentrate the biomass after the culture is delivered with a pump through PVC pipes into a special processing building. The biomass slurry is then moved to a vacuum belt, where it undergoes a final cleaning process after being further dehydrated as a paste. The moisture from the A. platensis paste is subsequently removed using a spray dryer, producing the fine free-flowing powder that is generally referred to as spirulina. It takes less than 15 minutes to complete the process from pond to powder. In order to conduct microbiological tests and other quality-control inspections, samples of the powder are collected in sterile bags, tagged, and brought to the quality control laboratory. All data is logged by the lab personnel onto written sheets and entered a database on the computer network. Once the study demonstrates that the product complies with the standards and regulations, the Quality Control Department releases the goods for packaging and inventory (Belay, 2007).
The advantages of spirulina cultivation are: • The culture of spirulina does not require fertile soil and can benefit from saline conditions. • Spirulina is used as a dietary feed for fish, shrimp, and poultry and also as protein and vitamin supplements for aqua feed and human consumption. The most important naturally occurring minerals contribute to 7% of the weight of spirulina (Ahsan et al., 2008).
• Fresh dried spirulina can be preserved in special oxygen barrier containers for five years or more, maintaining almost the maximum potency of beta carotene (Henrikson, 2010).

NUTRITIVE COMPOSITION OF SPIRULINA
Spirulina is considered as a Superfood owing to its rich nutrient composition including protein, essential amino acids, essential fatty acids, minerals, vitamins, phytochemicals, and sulphated polysaccharides. The nutritional composition of spirulina varies greatly according to the culture conditions and analysis methods. The nutrition profile of spirulina powder per 100g from various companies is listed in Table 1.  (Henrikson, 2010). Spirulina can increase the protein value of foods limited in certain amino acids such as rice, wheat, or corn, and is thus seen as a nutritional supplementation (Becker, 1993). It is considered a complete protein owing to the presence of all essential amino acids and nonessential amino acids in sufficient quantities. From Table 1, it is found that the highest level of essential amino acid in spirulina is tryptophan (9.00 g/100g) by FAT while the lowest is histidine (0.50 g/100g) by Parry Nutraceuticals. Likewise, the highest content of non-essential amino is glutamic acid (9.29 g/100g) by DIC Lifetec Co. Ltd while the lowest is found to be cystine (0.50 g/100g) by Parry Nutraceuticals. A typical pregnant woman advised to take a higher protein intake but not a corresponding increase in calories can consume spirulina, a rich protein, and a lowcalorie food. Spirulina is suitable in cases where the 'calorie cost' is far lower than dairy, meat, and fish (Henrikson, 2010). Spirulina exhibits high BV compared to all other plant-based foods and is proximately close to reference protein casein (animal-based) as shown in Table 2. It has relatively high DC, high NPU, and high PER. Although PER is inferior in spirulina to that of animal protein, it is much higher than most vegetable proteins (Salmean et al., 2015). Spirulina has a high amount of polyunsaturated fatty acids (PUFA's-1.50-2.00%), essential fatty acids (5.00-8.20 %), and saturated fatty acids. The highest total fat percentage in spirulina was given by DIC Lifetec Co. Ltd as 8.20%. In particular, it is rich in gamma-linolenic acid, alpha-linolenic acid, oleic acid, EPA, and DHA (Henrikson, 1989

MICROBIOLOGICAL QUALITY AND CONTAMINANT SPECIFICATIONS OF SPIRULINA
The author Sharoba (2014) has stated that the total viable bacterial count is widely used as an indicator microbiological quality of food. It is evident from the data ( Table 3) that the total viable bacterial count and mesophilic spore formers bacteria were absent in baby foods prepared with Spirulina. Furthermore, yeast, and molds were also not detected due to the fact that both are destroyed during drying. Likewise, coliform group, salmonella, and staphylococcus were not detected. On the other hand, spirulina is free from pesticides, rodent hairs, and insect fragments. The level of heavy metals detected is also in line with the specifications of global food.

NUTRACEUTICAL PROPERTIES OF SPIRULINA
Spirulina is gaining more attention as a nutraceutical and a functional food owing to its perks of several therapeutic effects in the health food circuit. It is described by the United Nations as the 'most ideal food for mankind' and was declared as the 'best food for the future' in the World Food Conference, in 1974. In the late 1980s and early 90s, both the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA) proposed Spirulina as one of the principal foods that can be cultivated in long-term space missions and FDA validated it as 'one of the best protein sources. Spirulina is reported as a powerhouse of various nutrients like carbohydrates, protein, β-carotene, γlinolenic acid (GLA), vitamins, minerals, phytonutrients, sulpholipids, glycolipids and superoxide dismutase, etc that are missing in most people's diet. Spirulina incorporated into food products produces functional foods that have enriched nutritional value and numerous health benefits. The application of Spirulina so far in industries has been in the form of dry powder and not fresh form for value addition and food formulations. Nevertheless, recently

Antioxidant effect
The C-phycocyanin in Spirulina is an effective potential anti-cancer agent. Manoj et al. (1996) reported that the alcohol extract of Spirulina inhibited lipid peroxidation more effectively (65%) than the well-known potential antioxidants like tocopherol (35%), butylated hydroxy anisol (45%) and β-carotene (48%). The water extract of Spirulina is also shown to have a more antioxidant effect (76%) than gallic acid (54%) and chlorogenic acid (56%). One such compound is β-carotene (natural antioxidant) that scavenges hydroxyl and peroxyl free radicals in humans thus preventing the prevalence of degenerative diseases like cancer and also lipid peroxidation. While the deep pigmentation of blueberries produces a high ORAC (Oxygen Radical Absorbance Capacity) value of 2600, Spirulina exhibits a fivefold higher ORAC value of 13000. Thus, Spirulina by its antioxidant activity functions as an anti-carcinogen, anti-tumor and a chemopreventive tool.

Anti-microbial effect
Spirulina acts as a functional food, feeding the beneficial intestinal flora, Lactobacillus, and Bifidus. S. platensis biomass was used to maintain the counts of starter organisms in acidophilus-bifidus-thermophilus (ABT) type culture in milk at satisfactory levels during the whole duration of storage. This is a novel opportunity for the production and maintenance of functional dairy foods (

Anti-inflammatory, anti-aging, and neuroprotective effect
The anti-inflammatory effect of Spirulina is due to the presence of phycocyanin which prevented inflammatory stomach and intestinal diseases providing favourable condition for the complete absorption of nutrients (Kodentsova et al.,  2001). Studies with aged rats showed diets with Spirulina down-regulated markers of inflammation and oxidative stress and improved receptor function in aged rat brains (Gemma et al., 2002). An earlier human feeding study conducted in S. platensis, it proved its neuroprotective ability. Hence, it is suggested that chronic treatment with Spirulina can reduce ischemic brain damage (Wang et al., 2005).
Spirulina is a potent food that has many actions in the central nervous system to counteract oxidative stress and inflammation that occur as a consequence of aging and to aid regeneration of the brain following injury or neurodegenerative disease (Vila and Gemma, 2017). Spirulina is the only green plant food rich in γ-linolenic acid (GLA), an essential fatty acid which acts as an anti-inflammatory, and sometimes alleviates symptoms of arthritic conditions. Spirulina reduces hepatic damage due to drug abuse and heavy metal exposure, inflammatory response, cell degeneration, and anaphylactic reaction (Usharani et al., 2012). Spirulina can be considered a therapeutic intervention for the aging brain. Spirulina aids in reducing

Detoxifying effect
Spirulina has a unique quality to detoxify (neutralize) or to chelate toxic minerals, a characteristic that is not yet confirmed in any other microalgae (Okamura and Aoyama, 1994). At Beijing University, bioactive molecules from Spirulina have been extracted which could neutralize toxic, and poisonous effects of heavy metals, and showed anti-tumor activity. Therefore, Spirulina could also be used to detoxify the poisonous effect of heavy metals (minerals such as arsenic) from water, food, and the environment. An earlier study successfully showed that Spirulina counteracted heavy metals in toxic kidneys assisting the detoxification process (Fukino et al., 1990).

Nourishing effect
Spirulina is a very rich source of vitamin B12 (cyanocobalamin) that is used as a supplement in the treatment of pernicious anemia which is caused by vitamin B12 deficiency (Richmond, 1995). A study by Fox (1984) proved that Spirulina combated vitamin deficiency in 10 weeks -2 months with an increase in plasma vitamin B12 and hemoglobin after 12 weeks. Henrikson (1989) stressed the iron content of Spirulina (1.18 mg/g) and the importance of Spirulina for treating iron deficiency (anaemia), particularly in pregnant women and children. As a comparison, iron supplements given in form of ferrous sulfate possess a toxicity problem and often cause diarrhoea. Cereals which contain phytic acids and phosphatic polymers sharply limit the bioavailability of the iron they contain. Spirulina contains iron twice as absorbable as that of vegetables. Elderly people who are on restricted diets and are suffering from intestinal malabsorption find Spirulina's protein easy to digest since it is composed of easily digestible soft mucopolysaccharides (Henrikson, 2010).

The research conducted by Madhu et al. (2001)
has revealed that the potential use of Spirulina as a food supplement and food additive for combating Protein Energy Malnutrition (PEM) and Protein Energy Wasting (PEW). Researchers conclude that Spirulina is a genuine health food for children as it was studied to curb bad appetite, night sweats, diarrhoea, constipation, and zinc deficiency. It is recommended to take < 4 grams of Spirulina per day for a healthy adult due to the presence of excess vitamin A and not more than 10 grams as it exceeds the RDA values of heavy metals. Fortifying food products with Spirulina effectively decrease diseases linked to nutritional deficiencies, creates nutritional awareness, and increases the acceptance level in developing countries.

Immuno-stimulatory effect
Many beneficial outcomes of Spirulina could be linked to the activation of the innate immune system, first line of defense in our bodies. Phycocyanin prevents degenerative organ diseases by boosting immunity and strengthening the body's resistance through the lymph system. A study by

Anti-obesity
Studies have shown that βcarotene in Spirulina reduces serum cholesterol levels in human beings and significantly reduces body weight. The hypercholesterolemic effect of Spirulina was due to functional lipids like γ-linolenic acid and linoleic acid which accounts for approx. 30% of total lipids (Henrikson, 2010). A study by Moradi et al. (2019) revealed that Spirulina causes significant weight change in obese subjects by changing the gut microbiota composition and growth of beneficial bacteria (Nagaoka et al., 2005). The phenylalanine content in Spirulina is responsible for the release of cholecystokinin that affects the appetite center in the brain (Fujimoto et al., 2012) and also improves leptin secretion from visceral fat, the impairment of which disturbs the homeostasis leading to obesity (Vázquez  et al., 2015). Spirulina has also been shown to raise adiponectin levels which are considered as a therapeutic target to treat obesity (Achari and Jain, 2017). Thus, the study by Moradi et al. (2019) suggested that Spirulina supplementation reduced body weight, body fat percentage, and waist circumference but had no effect on BMI and waist-to-hip ratio.

Anti-diabetic effect
Anitha and Chandralekha (2010) reported supplementation of Spirulina on fasting blood glucose and lipid profile. Spirulina was supplemented for 90 days with 2 capsules (500 mg each) per day. There was a significant reduction from preto post-levels of fasting blood glucose, glycosylated hemoglobin, and lipid profile levels of the diabetics upon supplementation with Spirulina. Takai et al. (1991) found that a water-soluble fraction of spirulina extract was effective in lowering serum glucose levels at fasting while the water-insoluble fraction suppressed glucose levels at glucose loading thereby controlling diabetes mellitus.

Miscellaneous effects
Spirulina contains vitamin A, important in preventing eye diseases; iron and vitamin B12, useful in treating hypo ferric anemia and pernicious anemia, respectively (Usharani et al., 2012). Also, the metalloprotective role of Spirulina may be attributed to the presence of beta-carotene, vitamins C, E, superoxide dismutase, selenium, and brilliant blue polypeptide pigment phycocyanin (Marzieh et al., 2013). Prostaglandin in humans regulates blood pressure, synthesizes cholesterol, and proliferates cells and inflammation. These are formed from its precursor gamma-linolenic acid (GLA), an essential fatty acid whose deficiency can cause degenerative diseases and chronic health problems. Spirulina, a dietary source of GLA may help overcome heart disease, premenstrual stress, arthritis, manic-depression, and schizophrenia. Thus, Spirulina is highly suitable for children and their growth owing to its high protein, calcium, and iron content for bodybuilding. While Spirulina is often used for human consumption in form of powder, tablets, capsules, and extracts, the functional features of S. platensis led to be used in processing usual foods. Such a profusion of therapeutic applications -genuine or supposed -is bound to leave Spirulina with the image of a miracle potion. The fact remains that a simple natural food supplement, endowed with the riches of this product, could well improve a good number of pathological conditions.

Bread
Spirulina when added to dough showed a significant increase in essential nutrients. Minh (2014) reported a significant increase in the nutritional quality of dough when supplemented with Spirulina (1%, 2%, and 3%). There was an increase in protein (9.6% to 11.0%), lipid (5.0% to 5.7%), total mineral (1.3% to 3.1%), and energy (307.4 kcal to 312.1 kcal). Results showed that bread with 1% of Spirulina is ideal because of its high nutrients and sensory characteristics (Table 5).

Similarly, Burcu et al. (2016) indicated that the bread formulated with 10%
Spirulina has a more significant micronutrient content than the control group. The amount of iron found was higher in Spirulina fortified bread.

Rozylo et al. (2017)
demonstrated that the fortification of bread with 4% Spirulina considerably increased its loaf volume. Furthermore, rheology and gas retention properties were increased noticeably in the fortified dough. The addition of 6.0% and higher spirulina significantly affected the total phenolics in gluten-free bread and results showed 4% of spirulina fortification is tolerable. The addition of 2.6% of Spirulina in dough increased the protein by 22.6 % (Lucas et al., 2017). Niccolai et al.
(2019) developed 2% Spirulina incorporated "crostini", a leavened bakery product that is largely consumed in Europe. Despite a lower volume increase compared to the control, the A. platensis "crostini" dough reached a technologically appropriate volume after fermentation. As A. platensis "crostini" showed higher protein content compared to the control, the newly developed "Spirulina crostini" could be regarded as a very interesting protein-fortified bakery product, with a protein value as high as 14-17% and significantly higher antioxidant capacity. Considering the European Commission Regulation on nutritional claims, "crostini" incorporated with 6% and 10% biomass was claimed to be a "source of protein". The combination of Spirulina biomass addition and sourdough technology led to the development of a novel microalgae-based bakery product with nutritional and functional features. Wandurraga et al. (2019) enriched breadsticks with 1.5% Arthrospira platensis and classified it as a high in iron and selenium food" with more a stable colour, and texture.

Biscuit
Sharma and Dunkwal (2012) reported that the incorporation of 1% Spirulina in biscuits notably improved the nutritional quality of biscuits. Clearly, there was an increase in energy (506 kcal), protein (19.6%), fiber (2.08%), iron (17.62 mg/100g), and potassium (292 mg/100g) (Table 5). Likewise, Sahin (2019) indicated that an addition of 2% of Spirulina presented a significant increase in protein, and essential amino acids in Spirulina-based biscuits compared to the control sample. There is about a 15%-18% increase in essential amino acids and considerably low lipid content seen in Spirulina-based biscuits. According to Ghaly et al. (2015), the odor of the Spirulina fortified chocolate chip oatmeal cookies of concentrations 0, 3%, 6%, and 9% were described as pleasant, sweetyeast smell, musty sea water, and fishy seawater respectively. The cookies that received Spirulina had a grainy texture and dry-chewy mouth feel. Spirulina has enhanced the nutritional value of the cookies by increasing the protein, vitamin, and mineral contents and omega 3 and omega 6 fatty acids. A similar study was conducted by Batista et al. (2017) and that the biscuits added with 2 and 6% Spirulina showed higher content of polyphenols and an improved antioxidant capacity besides obtaining an attractive and innovative appearance. Spirulina contains all essential amino acids which are not synthesized by the human body but must be supplied in the diet. The daily intake of essential amino acids is 4 mg/day stated by (FAO/WHO, 1991). Fortification of Spirulina (2%) in biscuit as a natural ingredient will fulfill all essential amino acid and protein requirements as suggested by (Sahin, 2019). Ali et al. (2019)

Cheese
In a study conducted by Darwish (2017), the fortification of Spirulina at a concentration of 1.5 % improved the protein and iron content of cheese. Kareish cheese developed with 1% Spirulina was higher in phenolic compound (18.437 mg GAE/100g) and flavonoid compounds (6.391 mg CE/100g) than the control sample. Also, kareish cheese presented a higher β-carotene, DPPH radical scavenging activity. However, 1% Spirulina-fortified cheese was observed to be more acceptable than 0.5% and 1.5% (Ismaiel et al., 2016). On the other hand, Mohamed et al. (2020) indicated that the spreadable processed cheese to sample with 3% Spirulina had higher chemical components like protein (13.66% to 14.67%), and fiber (0.0% to 0.27%). The spreadable processed cheese with 1% of Spirulina was considered to be more acceptable (Table 5). Agustinia et al. (2016) reported there was an increase in protein, and β-carotene (0.57% to 8.08%) in Spirulina (1.5%) fortified cheese sample. The author says addition of 1.5% was considered the best concentration for cheese preparation.
Yogurt Malik et al. (2013) reported that fortification of yogurt with Spirulina (0.1%, 0.2%, 0.3%, and 0.5%) considerably increased macro-nutrients like protein (3.80% to 4.17%), and iron (0.04 mg to 0.32 mg) and there was a higher curd strength observed with increasing supplements of Spirulina. As suggested by the author, 0.3% of Spirulina concentration was ideal and acceptable in yogurt. Dubey and Kumari (2011) indicated that yogurt formulated with 8% Spirulina showed a significant increase in protein (10.5% to 36.94%), and β-carotene (662.5 µg/100g to 2712.75 µg/100g) than the control sample. The incorporation of 6% of Spirulina was considered to be highly acceptable. In another study, Agustini et al. (2017) compared two samples of yogurt with different concentrations of Spirulina incorporated in it. Yogurt enriched with 1% Spirulina was comfortably accepted. Also, in a study conducted by Patel et al. (2019) probiotic control yogurt was compared to probiotic Spirulina yogurt (6-10% Spirulina) and results showed that there was an increase in total carotenoid content (0.01 mg/100g to 0.32 mg/100g), and chlorophyll content (0.04 mg/100g to 0.63 mg/100g). The RDA of β-carotene for an adult Indian man and woman is 4800 µg/day and for children (4-6 years) is 3200 µg/day (ICMR 2010). As suggested by the author 7% of Spirulina enriched probiotic yogurt was more nutritious and acceptable.

Ice-cream
Spirulina can be used to increase the nutritional quality of the ice cream as it contains high amount of protein, fat, and moisture. Spirulina powder (0.075%, 0.15%, 0.23%, and 0.3%) was used to replace the stabilizer in ice cream preparation. Walstra and Jenness (1984) demonstrated that there was an increase in acidity in Spirulina fortified ice-cream due to buffering action of the additional proteins, phosphates, citrates, lactates, and other miscellaneous milk constituents. Also, Malik et al. (2013) indicated that the addition of Spirulina by removal of stabilizer showed a significant increase in protein (4.26% to 4.45%), and iron (0.03 mg/100ml to 0.20 mg/100ml). Ice-cream prepared by replacing 50% of stabilizer with 0.15% of spirulina was observed to be more acceptable. Bulgaru (2019) demonstrated that replacing gelatin with Spirulina as a stabilizer provides a highquality index and increased biological value of ice-cream. The addition of Spirulina as a stabilizer increased the iron content from 2.68% to 3.98% and thus the chemical composition of the ice cream was improved. Replacing gelatin with 100% of Spirulina, as a stabilizer was preferable for the preparation of ice cream. Szmejda et al. (2018) conducted a study in which different flavour of ice-cream was compared to their version supplemented ice cream with Spirulina. There was a greater antioxidant potential, total soluble phenolic content, and β-carotene found in ice cream enriched with Spirulina and was more acceptable.

Spirulina Incorporated Extruded Products
Food extrusion has been widely used to produce ready-to-eat cereals, and snack foods. Physical characteristics of an extruded snack product such as expansion, hardness, and density are important parameters in terms of the consumer acceptability as well as the functional properties of the final product. Successful incorporation of Spirulina into cereal-based extruded products could deliver physiologically active components and represents a major opportunity for food processors who are engaged in providing the consumer with a healthy maize-based product. In connection with this, various studies have been demonstrated to evaluate the applicability of Spirulina in extruded products.

Spirulina Incorporated Energy Bar
Kumar et al. (2018) observed a 167% increase in protein content with the incorporation of Spirulina biomass into nutrition bars. Spirulina contributes small amounts of abundantly nutritious lipids like alpha-linolenic acid, linoleic acid, EPA, DHA, and arachidonic acid. The total phenolic content was found to elevate a maximum of 7.9 mg GAE/g in the 7utria-bar. It was also noticed that bars with higher content of Spirulina (6g/ 80 g nutrition bar) had a stronger appeal.

Spirulina-based Baby Foods
Spirulina is loved by children, and it is safe and highly nutritious for them and can easily assimilate its nutrients. Spirulina can create tissue growth, enhance vision, improves the immune system, healing capacity, and the ability to focus on children.
Thus, spirulina formula can be used for babies who are unable to swallow the capsules. It is also possible to blend powdered spirulina formulas with fruit juice, milk, salads, and convenient soups. Sixteen nutritional formulas were prepared for babies (1-3 years of age) as supplementary nutrition using Spirulina at 0, 2.5, 5, and 7.5 percent for the manufacture of sixteen forms of baby foods. Based on the results of sensory evaluation and chemical composition, four formulas containing 5% of spirulina was found to be suitable as a baby food for children aged between 1-3 years. The significance of spirulina is that regular use can regulate the alkaline levels in the body and aids in weight loss, it also nourishes and renews our body and health respectively (Sharoba, 2014).

Spirulina based Confectionaries
In any generation, biscuits and chocolates are the most consumed snack foods, considering their low protein content and high presence of unhealthy ingredients. In recent years, there has been an increasing interest in fortifying and/or enriching the nutritional value of foods, especially for children's diets (Polter et al., 2013).
A study by Rathod and Annapure (2016), confectionary samples were prepared by 2g of Spirulina biomass. Appropriate protein content and rich amino acid profile were found in homemade biscuits and chocolates designed with 2 % (w / w) of Spirulina as a natural ingredient, with a substantial increase in the daily intake of essential amino acids, histidine, and arginine, for infants and children Amino acids like phenylalanine and tyrosine (aromatic) and methionine (sulphur) in Spirulina enriched chocolates almost fulfilled the daily intake (RDI) as 25 and 15 mg/kg respectively (Sahin, 2019).

Spirulina Millet Mix Flour (SMMF)
Saggu and Sundaravalli (2016) developed Spirulina millet mix flour (SMMF) that contained a rich nutrient profile of 378.84 Kcal energy, 16.07 g protein, 1.24 g fiber, 299.6 g calcium, 20.16 g of iron per 100g and 4.6 meq peroxide content per 1000 g. Of the traditional recipes developed, 50% SMMF chapathi, and burfi, 75% SMMF dhoklas and onion pakoras, and 100% SMMF muffins were found most acceptable. Thus, by the efficient combination of Spirulina and millets, SMMF can reach households and help tackle public health issues like iron deficiency anaemia. High in micro-minerals selenium and iron, product is more stable in colour and texture.

Chocolate chip oatmeal cookies
Soft butter, brown sugar, wheat flour, cooking oats, chocolate chips, eggs, baking soda, salt, and vanilla 3, 6, and 9 3 Adding spirulina to cookies affected their smell, color, appearance, texture and taste. The addition of spirulina affected the easiness with which breaking a cookie was made, the fragmentation and the appearance of the break line.

Ghaly et al. (2015)
Souffle cake Eggs, corn flour, dry fruits, and sugar 4, 6, 8, and 10 8 Better organoleptic properties viz, Colour and Appearance, Body and Texture, Flavour and Taste and Overall Acceptability. The microbial count was found to be within the limit.

Ali et al. (2019)
Yazdi cupcake Noodles Wheat Flour and water 5 5 Developed food products were nutritious and their nutritional value is much greater, higher acceptability on organoleptic parameters.

Fatima et al. (2017)
Snack foods Organic corn flour, and organic rice flour 0.4, 1.8, and 3.2 2.6 Increase protein concentration, expansion index, ΔE and to reduce the bulk density and hardness of the snacks.

Energy bars
Bengal gram, groundnut, puffed rice, coconut flakes, cornflakes, jaggery, ghee and liquid glucose 3, 4, 5, and 6 6 Increased in the carotenoid content, protein content and zinc content, showed desirable hardness and did not lack cohesion.

Sports nutrition drink
Banana, wild berries, and natural yoghurt 1.5, 2.0, and 2.5 2.0 Increased protein and a vitaminmineral complex on the improvement of competitive activity noted.

Aleksandrovna (2019)
Broccoli soup Boiled broccoli, boiling water, olive oil, and salt. 0.5, 1.0, 1.5, and 2.0 0.5 Higher phenolic content and antioxidant activity, The amount of bio accessible polyphenols as well as the antioxidant capacity of the digestive enzymatic extracts was also higher.

Baby foods
Fruits, sugar, wheat flour, rice, barley, lentil, chickpea, spinach, cauliflower, and peas 0, 2.5, 5 and 7.5 5 Regulating the alkaline levels in the body and aids in weight loss; also nourishes and renews body.

Chocolates
Coconut butter, cacao, and grape molasses 2 2 Substantial increase of amino acids like phenylalanine, tyrosine and methionine.

DOSAGE AND RECOMMENDATION
Spirulina when consumed anywhere between 1.0 g-8.0 g per day is found to offer various health benefits. The maximum intake of spirulina for an elderly person is 2.0-3.0g/day, and for children, it is 1.0-2.0g/day (94). Nevertheless, the exact dosage of Spirulina depends on the disorder for which it is prescribed (Patel, 2020).

•
For cholesterol, a dosage between 1.0g to 8.0g per day has some effect. • For muscle efficiency, doses of 2.0g to 7.5g per day shows some effect. • For blood glucose control, dosage of 2.0g per day showed a mild effect. • For blood pressure, dosage of 3.5 to 4.5 shows some effect. As per Patel (2020), the suggested dosage of Spirulina for a person based on weight is as follows: • 150 lb person-11.0g of spirulina • 200 lb person-14.5g of spirulina • 250 lb person-18.2g of spirulina According to the experience of long-time consumers and scientific evidence, consumption of 3.0 to 10.0 grams of spirulina per day provides a significant health benefit. It is evaluated that daily use is most beneficial. Spirulina consumed in the form of tablets, between, before, or with meals is convenient. Many consumers mix spirulina powder in fruit smoothies as instant breakfast and vegetable smoothies as an instant food for the afternoon (Seema and Sonia, 2015). The SCF (The Scientific Committee on Food) and EFSA (European Food Safety Association) also recommend 10g as the maximum dosage per day. Spirulina as a daily supplement has no records of toxicity (FDA, 2013). Though spirulina has been termed as a non-toxic supplement and proved safe for consumption, researchers continue to check its safety (Shiomi and Waisundara, 2017). It is still a debate if spirulina can be consumed only once a day in the recommended dosage or multiple times a day in small dosages. Even when consumed less or more than the recommended dosage, there were no significant effects (Patel, 2020).

CONCLUSION
Exploring microalgae as a source of human and animal feed is not new and is been followed for centuries. They offer a wide range of food and non-food applications and can a stand extreme conditions, also they are non-seasonal. Spirulina particularly is extremely nutritious and even reported to be non-toxic consequently it can be safely consumed and recommended as a human food. We can conclude that the benefits of spirulina consumption are innumerable i.e., it has significantly higher essential nutrients, bioactive compounds, physiological health benefits, and non-toxic to name a few. Hence, spirulina can be considered to be a promising alternative to feed the future world and fight against malnutrition as well as other nutritional disorders.

FUTURE PERSPECTIVES
Spirulina being titled the 'Food for future' has also been entitled as the 'Biofuel of the future'. From a long history, algae are an essential part of Earth's selfregulating life support system. Diverse applications of it have led to an innovative dream of utilizing algae to re-green the deserts, re-fertilize depleted soils, clean the oceans, etc moving to a more sustainable and realistic business model. Better discovery of Spirulina with superior properties will pave way for futuristic developments such as biofuel and bio-packaging that will represent the return of the origin of life for individuals and planetary health and restoration. Multitalented Spirulina alga will reduce the production costs of many products by replacing fossil fuel chemical products with biopolymers and bioplastics thus envisioning a bright future with it.