[India] The global hunger index (GHI) ranks India high with regard to proportion of calorie-deficient or undernourished population and prevalence of underweight children up to the age of five and their mortality.
UN estimates that 2.1 million Indian children die before reaching the age of five every year. Although India improved its position in GHI by climbing to 55th position in 2014 from previous year’s performance at 63rd place, it still lags behind Thailand, China, Ghana, Iraq, Sri Lanka and Nepal. GHI, however, does not consider nourishment aspect.
India is among most poverty-stricken regions in the world and ranked third based on the available statistics. This affects the availability of nutrient-rich food to the larger proportion of population especially in the lower economic strata. Though government efforts to bring Food Security Act are laudable, it needs to ascertain that nutrition security can be simultaneously achieved. Options that could bring affordable nutrition would be better to avoid dependency on non-vegetarian edible source for fulfiling the need for proteins, vitamins, amino acids, fatty acids and micronutrients.
Although the precise world statistic is not available, staggering 31% Indian population (over 350 million people) consists of pure vegetarians. In India, the peace towards animals ahimsa brought vegetarianism among religious followers and philosophers. However production of vegetable crops needs sufficient agricultural land, and adequate water for irrigation with substantial expenditure towards fertilisers and pesticides, which are fast dwindling due to population upsurge.
Marine algae (better alternative to misnomer “seaweeds”) are wonder plants that could be incorporated into the human diet to improve the nutrition of vegetarian community. This group of lower organisms existed for over 2.5 billion years and therefore exhibit plethora of active chemical compounds especially developed for their own survival which could essentially be utilised for health benefit.
In the Far East and Pacific, there has been a long tradition of consuming marine algae as sea vegetables. Sea vegetables were the regular diet of Celtic culture, while the reference of consuming marine algae could be traced to beginning of fourth century in Japan and during sixth century in China. This long tradition of consuming marine algae has led to several epidemiological studies confirming their health benefits. Apart from micro elements, vitamins and fibres they are the rich sources of polyunsaturated fatty acids (PUFA), mainly long chain Omega-3 fatty acids. These needs to be obtained only through diet as human body cannot synthesise them.
The global eating patterns of humankind have undergone marked changes due to globalisation of the market. According to a report published on utilisation of marine resources worldwide for human consumption, 65% of 221 marine algae have been exploited for edible purpose. They are increasingly being utilised as food item apart from gelling agent in the form of garnishing agent, condiments, soups, green tea and spice.
Novel products such as low sodium salt of botanical origin were developed by CSIR-Central Salt and Marine Chemicals Research Institute, Bhavnagar. This salt is prepared using red alga Kappaphycus alvarezii – which is commercially being cultivated widely in tropical waters including India – and common halophyte Salicornia brachiata which is abundantly available. The marine algal tissue selectively accumulates higher amount of potassium salt. The salt contents 30% potassium chloride and 65% sodium chloride. The potassium also helps in slackening of muscles. Thus it is medically prescribed for hypertension patients. This salt is also naturally fortified with micro elements especially magnesium and iron as well. The free flowing salt can be obtained without any chemical processing. The second novel product developed from Kappaphycus alvarezii is refined juice for potential health drink application. The juice contains iodine, magnesium, calcium, sodium, zinc, phosphorus and iron and some of the compounds help brain function and boost immunity.
Iron and calcium content
The marine algal biomass can also be utilised for brimming snack food industry. The research conducted by CSIR-Central Food Technological Research Institute, Mysore, and CSIR-Central Salt and Marine Chemicals Research Institute have clearly shown that incorporation of most common edible green alga Enteromorpha compress in snack food such as pakora can increase iron and calcium content about five-fold. The calorific values of most of the marine algae are low which makes them ideal candidate for developing anti-obesity food products. Other compounds such as soluble fibres, antioxidants, amino acids, vitamin B12 can improve the dietary content of snack food which is otherwise considered as junk food. The antioxidant potential of several marine algae is being studied and it appears that some of these species possess good promise to utilise them for potential health benefits. The detailed study of over hundred marine algal taxa from tropical waters have suggested that the lipid content of these algae is much lower (> 20 mg/g fr wt) than land grown edible vegetables.
Nevertheless, a substantially high amount (up to 70%) of nutritionally important polyunsaturated fatty acids of total fatty acid composition was recorded. The incorporation of dried algal powder as in fast foods such as pasta, pizza and fried foods could act as cost-effective dietary supplement. Our studies carried out along the west coast of India showed that the mineral content of edible red alga Porphyra vietnamensis is higher than land vegetables and other edible marine algae such as Caulerpa lentillifera, Enteromorpha flexuosa, Monostroma oxysperum, Eucheuma denticulatum, and Gracilaria parvispora reported from Hawaii.
The recently-developed green method by us on integrated production of several compounds from fresh marine algal biomass explored possibility of utilising entire biomass including nutritionally important protein concentrate, having applications in food industry. The other interesting byproducts include pigments such as chlorophylls and phycobiliproteins having enormous applications in confectionery industry as edible food colourants.
Marine algal salads
The marine algal salads are immensely popular in countries like Korea, Japan, China and Vietnam. In southern and central Vietnam, agarophytes like local species of Gracilaria and Gelidiella are used for preparing edible jelly called “xu xoa.” The jelly is eaten with a sweet mixture of lime juice, sugar, coconut milk and ginger extract. The other popular edible alga is Gracilaria euchumatoides which has been used to prepare soft candy locally known as “che rau cau” available in roadside shops. The marine algal pudding is given to lactating mothers to improve breast feed in Korea. The fermented preparation prepared from green alga Codium is traditional delicacy in Far East countries. Marine algae have been the extraordinary source of an essential element ‘iodine’ which is absent in majority of other foods. Therefore, consuming marine algal products ensures maintaining healthy thyroid to avoid medical conditions like goitres.
The medicinal properties of marine algae have been studied extensively. Although, there have been several metabolites with biological activities reported, very few products with real potential applications have been developed or brought in the market. The most promising leads persuaded by commercial pharmaceutical companies in their R&D laboratories include sulfated polysaccharides with antiviral activities, halogenated furanones as antifouling compounds and kahalalide F from green marine alga Bryopsis for possible treatment in lung cancer, tumours and AIDS. The other compounds such as macro algal lectins, fucoidans, kainoids as well as aplysiatoxins have also been significant in drug discovery programmes. The consumption of marine algae regularly have shown to reduce the incidences of lifestyle associated diseases such as cancer, coronary heart ailments, neurodegenerative disorders and inflammation.
The key challenge is developing viable methods of commercial farming of marine algae which should be cost-effective and labour-intensive. The farming of edible algae such as Prophyra (Nori), and Monostroma (Awo-Nori) is traditionally being carried out in Japan. Although most of the polysaccharide yielding marine algae are cultivated using vegetative fragments, most of the edible algae propagate through spores. This required clear understanding of reproductive strategy and control over sporulation. The nursery techniques need to be implemented for rearing the germlings before outplanting in the sea. The recent biotechnological interventions such as protoplast isolation, fusion and tissue culture techniques could be implemented to develop new fast growing and high yielding varieties, along with conventional breeding methodologies. However, the latter is time-consuming and requires backcross to confirm the traits. Nevertheless, advancement in cultivation techniques to improve productivity, scalability and environmental acceptability is the need of the hour.
The food industry in India is worth around US$155 billion which is expected to reach about US$344 billion by the year 2025, with annual increase of about 4.1%. The share of snacks food alone is US$3 billion with an impressive rate of around 15-20% per annum. Close to 1,000 types of snack foods are available. The market is driven by creating innovative snack foods and thus there are plenty of opportunities for creating marine algal based snack food industries in India. Nevertheless, it is worth remembering that the marine algae do not always come with beneficial nutrition but also contain undesired chemicals especially heavy metals, more studies are thus desired.
(The authors are scientists from Marine Algal Research Station, Council of Scientific and Industrial Research and Central Salt and Marine Chemicals Research Institute, Council of Scientific and Industrial Research)
View original article at: Marine algae and their compounds as health and nutrition