Characteristics of powder agar extracted from different seaweeds species and locations in Indonesia

In Indonesia there are several production centers for agar-producing seaweeds. Research on agar quality has been frequently conducted everywhere, but comparative agar quality tests from several locations have never been done. The objective of this study was to assess the quality of agar extracted from seaweed species from some biggest seaweed producer locations in Indonesia. The seaweed quality indicators analyzed were moisture content, clean anhydrous weed (CAW), impurities, and heavy metals. Agar quality parameters analyzed were sensory (score and hedonic test), chemical (moisture, ash, acid insoluble ash, and sulphate content) and physical (viscosity, gel strength and color) parameters; microbiological (TPC, E. coli, moulds, and fungi) and heavy metals (Hg, Pb, Cd, As) contamination. Sensory analysis of powder agars showed that the highest score was achieved by agar extracted from Gracilaria from Ujung Genteng (8.71), and the highest yield was from Gracilaria from Brebes (10.41%). The viscosity and gel strength of agar extracted from Gelidium were higher than that from Gracilaria. It was concluded that environmental conditions affected seaweed and agar characteristics quality. It is recommended that to get a good quality seaweed, the seaweed must be harvested from a good quality waters with high dissolved oxygen and transparency, pH and handled appropriately.