Metal bioaccumulation potential of the seaweed Kappaphycus alvarezii

Kappaphycus alvarezii is one of the two main species of seaweed commodities cultivated in Indonesia. K. alvarezii more popularly known as Eucheuma cottonii, is belongs to the red algae. This seaweed is one of the most important commercial sources of carrageenans, a family of gel-forming, viscosifying polysaccharides. Carrageenans are used as gelling, thickening, and stabilizing agents in a variety of commercial applications, especially in food products such as frozen desserts, chocolate milk, cottage cheese, whipped cream, instant products, yoghurt, jellies, pet foods, and sauces. Aside from these functions, carrageenans are used in pharmaceutical formulations, cosmetics, and industrial applications such as mining. This study aimed to analyse the metal bioaccumulation potential of the seaweed K. alvarezii. This study was conducted in three sea areas around South Sulawesi, namely the Gulf of Bone, Flores Sea and the Makassar Strait. Seaweed samples were collected from seaweed cultivation locations in four locations (Regency of Jeneponto in two locations, Takalar and Pangkep). The metal concentrations analysed were Copper (Cu), Cadmium (Cd), and Lead (Pb). The concentration in Cu, Cd, and Pb in the seaweed K. alvarezii was higher than the concentration in ambient sea water. The seaweed K. alvarezii has a potential as a bioaccumulator, but the accumulation was not consistent. The Cu, Cd, and Pb probably can be accumulated or released back. This is good in terms of food safety because heavy metals can be released during post- harvest processing and carrageenan powder processing. The results of this study indicate that K. alvarezii has the potential for bioaccumulation, but not permanent accumulation, so it is safe for human health.