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Studies were made on thk effect of repeated harvesting on the growth of Sargassam cristaefolium, S. ilicifolium, S. polycystum, S. wightii and Turbinaria conoides occurring at Mandapam coast for a period of 2 years during June 1986 to November 1988. The growth of these algin yielding seaweeds depended on the period of harvesting and interval between one harvest and next. The maximum standing crop with plants of maximum stature was found during the period September to January in these brown algae. An interval of 7 months is required for the regrowth of these plants to harvestable size and the suitable season for commercial exploitation of these algae is September to January.

Green seaweeds are a potential source of proteins, minerals, fatty acids, and essential amino acids, and also often contain bioactive compounds with antioxidant activity. They have the potential to be a source of functional and nutraceutical ingredients. However, their elevated water content shortens shelf life; thus, a preservation method should be employed, such as drying. In the present article, Chilean green seaweed (Ulva spp.) was characterized and the effect of different drying methods (freeze-, vacuum-, solar-, and convective drying) on the quality of dried algae as functional ingredient, along with a description of the drying parameters for each method was evaluated. Proximate composition of fresh Ulva spp. indicated that, other than water, ash, protein, and crude fiber are the main constituents. Ulva samples also had a high amount of total dietary fiber (with an IFD/SFD ~ 1.5). The isotherm curve presented the typical type II sigmoid shape and the BET model gave the best fitting. There was a significant effect of drying method on proximate composition of dried Ulva and the convective drying the method that showed higher values for almost all parameters, except fat content. Color was not affected by drying and the typical green color was present in all samples. Total flavonoid content (TFC), total carotenoids and antioxidant capacity (DPPH and ORAC) were also higher in convective drying. In addition, other minor components with nutritional value were identified, such as essential polyunsaturated fatty acids (PUFAs with a ω3/ω6 ratio of 1:1) and amino acids. Among the different drying methods applied, convective drying (70 °C, 120 min) better retained the physicochemical parameters and antioxidant capacity of Ulva spp. 

The plants in the sea other than seagrasses—what we call seaweeds—belong to the simplest group of plants; the marine algae. With few exceptions, these plants are so simple that they have no distinguishable roots, stems or leaves. The algae vary in size from microscopic single-celled forms (eg. diatoms) to the giant macrophytes of temperate waters (Macrocystis, Nereocystis, etc).

Kappaphycus is one of the most significant, economically valuable red seaweeds, cultivated in tropical and subtropical waters. This alga demands a relatively high market value globally, due to applications of the kappa carrageenan colloid that is industrially extracted from the biomass. Carrageenan is widely used in food, pharmaceuticals, and nutraceuticals and for aquaculture applications. The first successful commercial cultivation of Kappaphycus (previously called Eucheuma) was recorded from the southern Philippines in the late 1960s using the line and stake method. Dramatic production increases were achieved, with the Philippines being the leading producer of Kappaphycus for more than 30 years, until it was overtaken by Indonesia (in approximately 2008). By 1988, Kappaphycus farming became widespread in Indonesia, and efforts have been undertaken to spread Kappaphycus farming to more than 30 countries worldwide. Since 2008 Kappaphycus production steadily rose in Indonesia, but production from the Philippines has tended to decline since 2011. Research and development (R&D) initiatives focusing on Kappaphycus in the Philippines emphasized the means to increase productivity and solutions to issues causing declining production. R&D focusing on Kappaphycus cultivars in the Philippines was made through the National Seaweed R&D Program. Several institutions and research centers took major steps to achieve these objectives. There were significant and relevant results obtained in studies of molecular taxonomy, factors affecting sporulation, tissue culture and mutagenesis, protoplast isolation, strain selection, mitigation of ‘ice–ice’ malaise and Neosiphonia infestations. A recent development in Kappaphycus farming was the discovery that use of an extract from a brown seaweed acts as a biostimulant to improve tolerance of cultivars to abiotic stresses. Problems and challenges encountered in the production of Kappaphycus, even after more than 40 years of farming, but which needed to be overcome, are discussed.