Seaweed, the wonder aquatic plant

For the fitness-freak/diet conscious eaters, this aquatic-plant provides nutrient-rich-low-fat-low-calorie-high fibre super food and dietary supplements. For those suffering from various lifestyle diseases or metabolic ailments, bioactive molecules (nutraceuticals) derived from the plant can offer relief and health benefits. For the environment conscious, edible, biodegradable natural biopolymer sachets derived from this plant can be a substitute for toxic, polluting plastics.

During the pandemic, hand sanitizers were also made from this plant. All thanks to this all-in-one magical aquatic herb – seaweed or macro algae and its multifarious applications.

After Prime Minister Narendra Modi emphasised on developing the blue economy in coastal states and asked stakeholders to re-focus on seaweed farming and research, the latter has been carried out in full swing in the pandemic years. Seaweeds (macro algae) have been put to multifarious uses, especially, in the food, agro and pharma sectors. Government marine scientists from top research institutes – namely the Central Marine Fisheries Research Institute (CMFRI) and Central Institute of Fisheries Technology (CIFT) under the aegis of Indian Council of Agricultural Research (ICAR) have come up with diversified and interesting natural, seaweed-based products and culture, which are primarily produced along the coasts of Tamil Nadu, Andhra Pradesh, Kerala and Gujarat.

India, with a total coastline of 7,517 km across its states and islands, has around 844 species of seaweeds. Seaweeds are broadly classified in three groups - Rhodophyta (red algae), Phaeophyta (brown algae) and Chlorophyta (green algae).

The Challenges

In India, most of the commercial scale seaweed cultivation takes place in Tamil Nadu and partly in Gujarat. Traditionally the raft method is used where bamboo raft-like structures containing shelves, which are prone to breakage and drifting off in case of a rough sea and cyclone. To counter it, scientists have devised an innovative HDP (high density polyethylene) Tubenet and grid-mooring method.

Explaining it, principal scientist of ICAR-CMFRI, Visakhapatnam Regional Centre, Subhadeep Ghosh, says, “In the last one year, we have developed an innovative method of protecting the seaweeds. The seaweed seedling (a species of red algae kappaphycus alvarezii) is cultivated in the HDP net, which is folded like a tube.  Around 25 HDP rafts are interlinked using polypropylene ropes and anchored using stainless steel chains and reinforced cement concrete (RCC) blocks at four corners to prevent them from drifting away during high currents and turbulent conditions. In one year, six cycles of seaweeds (45 days each) have been cultivated. There has been a fivefold increase of biomass through vegetative propagation since it was stocked. We have also applied for a patent for this method.”

Super-food

Diversifying the utilization of seaweed, scientists have also developed varieties of value-added food products and dietary supplements enriched with seaweed nutrients. This nutrient-rich, high-fibre super food is low in calories and fat, rich in antioxidants and polyunsaturated fatty acid (good fat), high in protein, iodine, calcium, copper, iron and vitamins (especially Vitamin K). It is being used to make nutra-drink and fucoidan dietary supplements, dietary fibre fortified-fish sausages, seaweed yoghurt, cookies, seaweed-enriched noodles and pasta.

Seaweed Fucoidan

Elaborating on the various edible products, researcher on seaweeds at ICAR-CIFT Jesmi Debbarma avers, “We have optimised the technology for dietary fibre extraction from a species of red seaweed — Gracilaria edulis — that grows abundantly in the East and West Coast of India. Dietary fibre helps in reducing incidences of coronary diseases and diabetes, gut neoplasia, prevents constipation and reduces colon cancer risks. A new product — seaweed dietary fibre fortified fish sausage has also been developed. The product can be produced by food/fish processors and marketed in retail markets, restaurants and retail food kiosks. For dietary supplement FucoidanEx, a brown seaweed Sargassum, is used. It is rich in fucoidan, which is a fucose-rich sulphated polysaccharide. Fucoidan possesses a number of bioactivities including anti-cancer, anti-thrombotic, anti-virus, antioxidant, anti-inflammatory, anti-diabetic and neuro-protective functions. Further, to reduce dependence on harmful plastic, red and green seaweeds have been converted to edible, biodegradable films and sachets for use in food packaging as biopolymers.”

Seaweed Yoghurt

Green Alternatives

ICAR-CMFRI has recently developed nutraceuticals (concentrated, isolated, or purified pharmacologically bioactive molecules with health benefits) for treatment of various ailments such as Type 2 diabetes, hypothyroid, obesity, hyperlipidemia, hypertension, arthritic pain etc. Most of these have been developed by principal scientist Kajal Chakraborty from CMFRI, Kochi centre.
Scientist Loveson L Edward from CMFRI informs, “Seaweeds exhibit distinct biological activities such as anti-tumoral, anti-viral, anti-fungal, insecticidal, cytotoxic, phytotoxic, and anti-proliferative actions. Marine-based resources are drawing the attention of nutraceutical industries due to their protective function against various chronic diseases and the growing demand for new compounds of ‘marine natural’ origin. Considering this, CMFRI had developed a research programme to systematically search identified seaweed species for developing bioactive molecules. These marine floras are considered as valuable sources of bioactive compounds with potential pharmacological significance. The extractions have been done using green technology.”

“The nutraceutical products CadalminTM Green Algal extract and CadalminTM Antidiabetic extract as green alternatives to synthetic drugs to combat rheumatoid arthritis pains or inflammatory diseases and Type-2 diabetes, respectively were developed from seaweeds. Following this, CadalminTM Antihypercholesterolemic extract and CadalminTM Antihypothyroidism extract to combat dyslipidemia and hypothyroid disorder respectively, were also developed.

Other useful seaweed extracts include CadalminTM AHe to regulate hypertension, CadalminTM AOe to treat osteoporosis, CadalminTM IBe to boost innate immunity in humans. CadalminTM Green Mussel extract (CadalminTM GMe) to combat joint pain and rheumatoid arthritis is however derived from green mussel and not seaweed,” informs the scientist.

Miscellaneous Uses

During the pandemic, seaweed-based hand sanitizer was developed by CIFT scientists. The sanitizer comprises isopropyl alcohol and carrageenan (extracted from red seaweed Kappaphycus alvarezii), which is found to have well-marked antimicrobial and antiviral properties. The formulations of seaweed-based products have also been found to be active against several enveloped viruses like herpes, influenza, HIV and cytomegalovirus. “Seaweed extracts are used as a biofertilizer as it has natural growth hormones NPK and organic micro-nutrients. Seaweeds are also the only sources for industrially important agar, carrageenan and alginate, which have applications as stabilizer, viscosifier, gelling and emulsifying agents in the food and cosmetic industry,” informs principal scientist and scientist in charge of CIFT, Vizag Centre, R Raghu Prakash.