Heavy metal accumulation in field cultured and tissue cultured Kappaphycus alvarezii and Gracilaria changii

Use of raw seaweed for direct consumption and its extract in food production has increased steadily throughout the world. However the ability of metal sorption in seaweed may result in accumulation of some heavy metals which could be harmful to consumers. Tissue culture has been considered as an alternative method to produce uncontaminated seaweeds as seedlings for sustainable farming and raw materials for various industries including food production. In this study, Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) was used to determine the metal concentration in both field cultured and tissue cultured Kappaphycus alvarezii and Gracilaria changii. Results indicated that concentration of heavy metals with great scientific importance such as arsenic (As), cadmium (Cd) and lead (Pb) from tissue cultured samples has met the specific standard of health requirement from Joint FAO/WHO Expert Committee on Food Additive (JECFA) and Health Council and National Medicine Academy of France. Tissue cultured seaweeds also appeared to have lower As, Cd and Pb concentrations as compared to field cultured seaweeds. This may due to the stable and clean environment provided in tissue culture, contrasting with uncontrollable seasonal inflow of heavy metals in the field.