Characteristics of Powder Agar Extracted from Different Seaweeds Species and Locations

Abstract In Indonesia, there are several production centers of agar-producing seaweeds. Research on agar quality has been frequently conducted everywhere, but agar quality test from several locations has never been done simultaneously. The objective of this experiment is to study the quality and characteristics of powder agar extracted from seaweeds harvested from different species and locations in Indonesia i.e., Gracilaria sp from Serang (Banten Province), Brebes (Central Java), and Ujung Genteng (West Java), as well as Gelidium sp from Ujung Genteng (West Java) and Gunung Kidul (Yogyakarta). Agar quality parameters were analyzed based on 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, and As) contamination. The environmental condition of seaweed growing habitat was also observed, including Dissolved Oxygen (DO), transparency, pH, temperature, salinity, and nutrient content (nitrate, phosphate, ammonia, nitrite, and sulphite). 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%). Viscosity and gel strength of agar extracted from Gelidium were higher than that from Gracilaria. The colour of powder agar was closely related to the salinity and water transparency of the seaweed growing habitat. It was concluded that seaweed species and locations affected agar characteristics and quality.