Article Info Received: 25 Jun, 2021 Accepted: 02 Sep, 2021 Keywords: Amino acids, Dietary fiber, Hydrocolloids, Vitamins https://doi.org/10.52151/aet2021453.1539 REVIEW ARTICLE Corresponding Author: Devinder Dhingra *E-mail: devinder.dhingra@gmail.com © 2021 Indian Society of Agricultural Engineers Seaweeds – a potential source of food, feed and fertiliser Devinder Dhingra 1, * (LM-7559), K. Kandiannan 2 1 Division of Agricultural Engineering, ICAR, New Delhi, India. 2 ICAR-Indian Institute of Spices Research, Kozhikode, India. ABSTRACT: Many communities in the world consume naturally growing and cultivated/ farmed seaweeds as food. Currently, commercial cultivation/farming produces more than 96% of seaweeds in the world and only around 3-4% is obtained from wild harvest (non- cultivated).Naturally occurring and cultivated seaweeds are categorized into green, brown and red seaweeds, based on their pigmentation. More than 200 species of seaweeds are of commercial value, but only around 10 species of seaweeds are popularly cultivated. China, Indonesia, the Republic of Korea and the Philippines are the leading producers of cultured/ farmed species (viz. Eucheuma, Japanese kelp, Gracilaria, Unndaria pinnatifid); and Chile, China and Norway for wild species (mainly brown and red) and Chilean kelp. Seaweeds are rich in dietary fiber (polysaccharides), essential amino acids, major and micronutrients (minerals), vitamins etc. It has been reported that some species are a good source of plant growth regulators. Mainly, the people in China, Japan and Korea relish the soups, stews, flakes, coatings, snacks, etc., made from seaweeds. The use of seaweeds as human food in India is not very common. The second major use of seaweeds after food is the extraction of three important hydrocolloids (Agar, Alginate and Carrageenan). These are used as food additives and in many other industrial applications. A small portion of seaweed is used as an ingredient as livestock feed and fish feed. Seaweed meal and liquid extract of seaweed have been tried in conjunction with inorganic fertilizers with beneficial effects on crop yield, quality produce and soil health. Seaweed is an important marine resource and the coastline in India can be utilized to commercially cultivate seaweed species beneficial for human health and plants. Research is required in developing functional foods, health foods and nutraceuticals from seaweeds to improve the health and nutritional status of the human population. This paper briefly describes the status of production and utilization of seaweeds in different parts of the world. 1. INTRODUCTION In the earliest times, the wild-growing seaweeds have been utilized by the coastal communities, solely as a food source. Seaweed, macro algae or marine algae comes in red, brown and green colours. Seaweeds grow as broad leaves, delicate fingers, spheres or resemble fruits. Seaweeds require seawater (or at least brackish water) and light sufficient to support photosynthesis. Seaweeds mostly grow on rocky shores in the littoral zone (nearshore water). However, few genera (Sargassum and Gracilaria) do not live attached to an anchor but float freely. Many seaweed species are edible and are consumed as food. Some seaweeds are incorporated as an ingredient in animal feed. Many species of seaweeds are of commercial importance to humans. Hydrocolloids (carrageenan, agar and alginate) are extracted from these seaweeds. Some seaweeds are used as fertilizers or as sources of polysaccharides (Alejandro et al., 2017 and Brown et al., 2014). Seaweeds are a rich source of sodium, calcium, magnesium, potassium, chlorine, sulphur, phosphorous; micronutrients (iodine, iron, zinc, copper, selenium, molybdenum, fluoride, manganese, boron, nickel and cobalt) and vitamins (B12, A and K) (Anonymous, 2004; MacArtain et al., 2007; Marsham et al., 2007). Seaweeds often form dense growths on rocky shores https://isae.in/agricultural-engineering-today-AET Agricultural Engineering Today Vol. 45 (3): July-September, 2021 ISAE AGRICULTURAL ENGINEERING TODAY Indian Society of Agricultural Engineers ISSN : 0970-2962 ISSN (Online): 2230-7265 Vol. 45(3) July-September, 2021 19