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Seaweeds in Philippine Food: Traditional Uses and Recent Developments

MARCO NEMESIO MONTANO

Marine Science Institute, College of Science, University of the Philippines, Diliman, Quezon City 1101 Philippines

SUMMARY: Seaweeds are traditionally used as fresh salad in the Philippines. The most popular seaweeds that are utilized in salad preparations are those belonging to the Caulerpa, Eucheuma and Gracilaria species. Aside from salad, seaweeds are also being used in other food preparations such as fish soups, seaweed dishes and desserts. Recent developments in Philippine seaweed polysaccharide research showed that carrageenan incorporated food products reduce blood glucose and can augment fiber intake, which could help in the dietary management of some metabolic conditions such as diabetes. Garrageenan gels have also been found to interact with saxitoxin thus reducing the toxicity of a shellfish infected extract by 60 -80%.

KEYWORDS: Philippine seaweeds, utilization, iodine deficiency, diabetes, saxitoxin,

INTRODUCTION TRADITIONAL USES

The Philippines is an archipelagic country Traditionally, seaweeds are considered as

(4•‹40" to 21•‹20" N latitude, 117•‹00" to vegetables and are eaten as salad or mixed with 127•‹00"E longitude) composed of 7,107 islands. other vegetables in soups and other dishes. The Bashi Channel bound it on the north, Aside from Kappaphycus and Echeuma, species Celebes Sea on the south, the South China Sea of Caulerpa, Codium, Acanthophora, Ahnfeltia, on the west and the Pacific Ocean on the east. If Ulva, Gracilaria, Sargassum, Laurencia, the Exclusive Economic Zone (EEZ) is Hydroclathratus, Porphyra, Liagora and considered, its land area is only 15% of its Halymenia are also eaten as vegetable. To date, territorial waters. Marine living resources are there are 280 seaweed species that are edible diverse and because of its rich marine broken down into 50 species belonging to biodiversity, the Philippines is considered at the Chlorophyceae, 53 species of Phaeophyceae, apex of marine biodiversity in Asia. Seaweeds and 177 species belonging to Rhodophyceae z). are one of the diverse groups of organisms A typical seaweed salad consists of blanched found in the country. Of the 1,062 species of seaweed to which vinegar, tomatoes, onions and seaweeds reported so far, only 531 are other species and condiments are added. economically important1). Eucheuma and Species of Halymenia have become popular due Kappaphycus spp., which are traditionally used to the delectable color it imparts to seaweed as sea vegetables, are being farmed making the salads. It might be of interest to know that the country as the supplier of 70% of the world's green seaweed Enteromorpha sp. ("Hoti" in raw material for carrageenan production. Chinese) is used as an ingredient in the fillings This paper is a status report on the traditional of Chinese lumpia or spring roll. Recently, fresh uses of Philippine seaweeds and recent research Caulerpa racemosa had been incorporated into developments related to nutrition and health. . noodles intended for the high end market3) Sargassum species are also used as herbal tea in 1458

some areas in the Philippines. Generally, these Algal polysaccharides are also noted for their seaweeds are low in protein but rich in minerals wide application in foods, but most of the and other essential nutrients4). While most studies conducted focused chiefly on its Filipinos know that seaweeds are edible and contribution to the improvement of the beneficial to health, the practice of eating functional and organoleptic properties. seaweeds is found only in the Ilocos region in Some of the recent studies in Philippine algal northern Luzon5,6) and in the coastal areas of polysaccharide placed emphasis on the role of Visayas and Mindanao. A project on the algal polysaccharide as source of dietary fiber publishing a comprehensive Philippine Marine and the health benefits of algal polysaccharide Food Composition Table has still to be incorporated food products. implemented. The table will help in the Semi-refined carrageenan and agar were advocacy of the consumption of seaweeds to incorporated in selected typical Filipino foods promote health. aiming to augment their dietary fiber content. For carrageenan incorporated food samples, RECENT DEVELOPMENTS addition of 0.58-4.48% carrageenan was found to increase the dietary fiber content up to 44%9) Although, the Philippines is surrounded with sea A greater effect was observed in agar that is rich with iodine, prevalence of Iodine incorporated foods, where the addition of 0.18 Deficiency Disorder (IDD) is wide spread 0.15% w/w agar increased the total dietary fiber especially in the inland provinces. Studies (TDF) content to as much as 20,400%(TDF conducted by the Division of Nutrition of the control: 0.02% wb, TDF food with agar: 4.10% Department of Health7) showed that many wb)10). Filipinos suffer from goiter and iodine Incorporating algal polysaccharides in food malnutrition. In the years 1976 to 1981 goiter products was also found to significantly reduce prevalence rate ranged from 32.9% to 66.4% in the blood glucose of both normal and non adult women. Most affected were pregnant and insulin dependent diabetes mellitus (NIDDM) lactating mothers. The provinces most affected subjects after short-term feeding of the test were the mountain provinces such as Kalinga foods"). However, in the long-term feeding, no Apayao, Ifugao, and Quirino. The report did not significant effect was observed on the total mention the prevalence of iodine malnutrition cholesterol and triglyceride level of both among children. Because of widespread subjects 9,11). malnutrition occurrence, the government Algal polysaccharides have also been found to response was to promote the use of iodized table interact with saxitoxin. The saxitoxins are salt. recognized as the compounds responsible for the However, there were objections to the use of human ailment named Paralytic Shellfish iodized salt mostly coming from those prone to Poisoning (PSP). PSP toxins are derivatives of hypertension. The use of seaweed tablet was an the imidazoline guanidinium groups, alternative solution to iodine deficiency problem. collectively known as Saxitoxins. These toxins In one study, species of seaweeds were contain two guanidine groups which, when both evaluated for its iodine and zinc content. are protonated (e.g. at pH 5 or lower), the Seaweed identified to have high level of iodine positive charges are fully localized over each. was Halymenia durvillaei (0.255% w/w) with Due to the inherent property of paralytic zinc (25.69 ppm) and phosphorous (11.68 ppm). shellfish toxins to interact with cation Heavy metal (Hg, Cd and Pb) content were exchangers, and the property of carrageenan as negligible"). Based on the chemical results, a an ion exchanger, it is possible that PSP would tablet was formulated according to the U.S. interact with carrageenan in an ion exchange recommended daily allowance of 0.15 mg of mechanism. The action of kappa-carrageenan iodine per adult and child. The seaweed tablet gel to sequester paralytic shellfish poison was was comparable to imported Kelp pills in terms tested and characterized. Using an extract from of chemical and physical properties. a Philippine strain of Pyrodinium bahamense Although the study was published in 1997, there var. compressum as PSP solution, the PSP- has been no effort to promote the use of the sequestering property of kappa-carrageenan gel product. was found to be dependent on gel surface area, 1459

interaction time and polysaccharide REFERENCES concentration. The interaction was found to be affected by high concentrations of monovalent 1. Philippines, DENR.. Philippine Biodiversity: cations. The characteristics of kappa an Assessment and Plan of Action. (Seaweed carrageenan as a PSP-sequestering agent all Information Center (SICEN) DataBase). Bookmark, Inc., Makati City. 1997; 298 pp. point to cation exchange as its mechanism of 2. Ganzon-Fortes, E.. Personal communication. action. It is also proposed that the 2001. polysaccharide gel can be utilized as an agent to 3. Capanzana, M.V.. Updates on the Utilization alleviate PSP intoxication12). of Seaweeds.(submitted for publication). 2001 Other types of carrageenans were also found to 4. The Philippine Food Composition Table.. reduce toxicity of PSP extracts. Different FNRI-DOST. Philippines. 1997. carrageenan types have different capacities to 5. Ragasa, A.L. Seaweed Profile of llocos reduce toxicity but the addition of electrolytes Norte. A paper presented at the First General such as KCl can bestow some kind of leveling Assembly of the Fisheries Post-Harvest Alumni Association. University of the Philippines, effect on the efficiencies of PSP sequestration. December 19,1999 The claim of PSP sequestration of the 6. Tungpalan, A.Y. Ethnobotanical Study of the carrageenans was confirmed by chemical Seaweeds of llocos Norte. Ilocos Fisheries analysis by HPLC of a sample carrageenan Journal, July 1983; 1(2):134 -146. interacted extract13) . 7. DOH. " A Terminal Report on Pilot Goiter

Project". Division of Nutrition, DOH, Manila. CONCLUSION 1987. 8. Briones, A.V., Ambal, W.O., Monroyo, E.C., The results of the recent survey of the Food and Bonifacio, T.S., and Sison, F.M. Seaweeds Tablet: Nutrition Research Institute of the Philippine A Natural Source of Iodine. Philippine Journal of Science 1997; 120(3): 221-232. Department of Science and Technology were 9. Dumelod, B.D., ramirez, R.P., Tiangson,

quite perplexing and disturbing as well. C.L.P., Barrios, E.B., and Panlasigui, L.N. Contrary to expectations, the population in the Carbohydrate Availability of Arroz Calllllldo with

coastal areas had higher incidences of ă carrageenan. Int. Journal of Food Science and hypertension and iodine deficiency than their Nutrition. 1999; 50 : 283-289. inland counterparts 14). A closer look at their 10. Panlasigui, L.N., Dumelod, B.D., Alonde, L., eating and consumption patterns of marine Torres, J., Basilio,A.L., Concepcion, M.T., derived food might reveal the reasons for such Mercado, L., and Olermo, C. Nutritional results. People in the coastal areas are generally Evaluation of Agar: Metabolic Effects of Local Seaweeds Extracts on Blood Sugar Level. Annual below the poverty level. The promotion for Report (May, 1997-June, 1998). increased consumption of the right kind of sea 11. Panlasigui, L.N., Dumelod, B.D., Tiangson, vegetables might be one activity to help reverse C.L.P., and Quijano, A.M. Blood Glucose the trend and, thereby, produce a healthier response of normal subjects to a carrageenan population of the Philippines. incorporated Filipino food. J. Nutritionist Dietitian Assoc. of the Philippines. 1997. 11:87 - 92. ACKNOWLEDGEMENT 12. Canete, S.J. and Montaho, M.N.E.. K - carrageenan Gel as Paralytic Shellfish Poison Sequestering Agent(submitted for publication). Acknowledgement with thanks are due to the 2001. staff of UP-MSI Seaweed Chemistry Group, 13. Montano, M.N.E., Canete, S.J., Conaco, particularly M.R. Rodrigueza and S.J. Canete. C.B., and Cruz, L.J. Toxicity reduction of The author is also grateful to Dr. Hideomi Paralytic Shellfish Poisoning (PSP) toxins by gels

Amano and the organizing committee for the of the Carrageenan types: an in vitro assessment

invitation and support. (submitted for publication). 2001. 14. FNRI-DOST. Fifth National Nutrition Survey. Philippines. 1998.