Solar irradiation as an alternative bleaching process for agar extracted from Gracilariopsis heteroclada in Iloilo, Philippines
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The current industrial practice of using chemical bleach to achieve the pure white colour of agar is deleterious to both human and environmental health. This study evaluates the potential of solar irradiation as an alternative bleaching process for agar extracted from Gracilariopsis heteroclada in Iloilo, Philippines. The physico-chemical properties of agar obtained from alkaline-treated seaweed after exposure to different bleaching conditions (e.g. solar irradiation, hypochlorite solution, and ultraviolet and fluorescent lights) were examined and compared with commercial bacteriological agar. Photobleaching through solar irradiation produced agar with superior gel strength (1038.61 g cm−2), high 3,6-anhydrogalactose content (41.44%) and low total inorganic sulphate content (1.87%) without compromising agar yield (19.37%). Solar irradiation offers very promising results as a simple, low-cost, environmentally friendly alternative to the chlorine bleaching process for agar extraction.
Endoma, L. F., Nacional, L. M., & Luhan, R. J. (2019). Solar irradiation as an alternative bleaching process for agar extracted from Gracilariopsis heteroclada in Iloilo, Philippines. Botanica Marina. https://doi.org/10.1515/bot-2018-0120
This study was funded by the Department of Science and Technology – Science Education Institute – Accelerated Science and Technology Human Resource Development Program (DOST-SEI ASTHRDP) and the University of the Philippines Visayas Thesis Support Grant. The authors would like to acknowledge the Institute of Fish Processing Technology, College of Fisheries and Ocean Sciences, University of the Philippines Visayas, and the Seaweed Laboratory of the Southeast Asian Fisheries and Development Center – Aquaculture Department (SEAFDEC-AQD) for providing access to laboratory facilities.
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Proceedings of the National Seaweed Planning Workshop held on August 2-3, 2001, SEAFDEC Aquaculture Department, Tigbauan, Iloilo. AQ Hurtado, NG Guanzon Jr., TR de Castro-Mallare & MRJ Luhan (Eds.) - 2002 - Aquaculture Department, Southeast Asian Fisheries Development CenterSeaweed forming is one of the major livelihoods among coastal communities in the Philippines, particularly to some 180,000 families in the Sulu Archipelago. In 1999, the Philippines exported more than 35,000 tons of dried seaweeds (US$ 44M) making the country the 4th largest producer of seaweeds and 8th largest producer of carrageenan in the world. However, improper post-harvest management (i.e. cleaning; drying by salting or steaming; adulteration of seaweeds with sand, dust, and dirt for added weight; storage; and baling) reduces quality, which eventually dictates the market price. The National Seaweed Planning Workshop was organized by a collaborative effort of SEAFDEC Aquaculture Department (AQD) and the Bureau of Fisheries and Aquatic Resources (BFAR) for the formulation of a Code of Practice for the Seaweed Industry in order to minimize industry malpractices and to sustain its position in the international market. The National Seaweed Planning Workshop invited several seaweed industry associations, and representatives from the government, NGOs and academic and research organizations conducting seaweed research and development to discuss the research and development programs of the different participating agencies, identify and validate problems and concerns of the seaweed industry, and agree on strategies of solving problems in seaweed farming like disease management, post-harvest facilities and research funding. This proceedings documents the National Seaweed Planning Workshop. Hopefully, the contributions would help in the drafting of the Code of Practice in attaining a sustainable seaweed industry.
Conference paperAQ Hurtado-Ponce - In F Lacanilao, RM Coloso & GF Quinitio (Eds.), Seminar-Workshop on Aquaculture Development in Southeast Asia and Prospects for Seafarming and Searanching; 19-23 August 1991; Iloilo City, Philippines., 1994 - Aquaculture Department, Southeast Asian Fisheries Development CenterThis paper reviews the studies on Gracilaria/Gracilariopsis conducted from 1988 to 1991 by the Aquaculture Department, Southeast Asian Fisheries Development Center. It includes 114 species of macrobenthic algae collected in Panay, the nomenclature of Gracilariopsis heteroclada previously described as Gracilaria sp., and the biology, ecology, and farming systems of Gracilariopsis. Agar quality of the different species of Gracilaria and the effect of seasonal variation on the quality and quantity of agar produced from Gracilariopsis heteroclada were also studied.
Conference paperGJB Cajipe - In IJ Dogma Jr., GC Trono Jr. & RA Tabbada (Eds.), Culture and use of algae in Southeast Asia. Proceedings of the Symposium on Culture and Utilization of Algae in Southeast Asia, 8-11 December 1981, Tigbauan, Iloilo, Philippines, 1990 - Aquaculture Department, Southeast Asian Fisheries Development CenterA brief discussion is presented on the commercial importance of seaweeds in the Philippines, which is mainly concerned with their use as sources of industrial gums such as agar, carrageenan, and alginic acid. Carrageenan as a substitute for microbiological agar and the use of seaweeds as a binder of heavy metal pollutants are examined.