Rumput laut adalah salah satu produk unggulan Indonesia dan menjadi sumber pendapatan bagi masyarakat di wilayah pesisir khususnya di pesisir Kabupaten Nunukan. Rumput laut yang dibudidayakan masyarakat di daerah ini salah satunya adalah jenis Eucheuma denticulatum atau nama lainnya adalah Eucheuma spinosum. Penelitian ini bertujuan untuk menentukan karakteristik Alkali Treated Spinosum (ATS) dari Eucheuma denticulatum berdasarkan umur panen yang terbaik. Penelitian ini menggunakan rumput laut yang berasal dari Kabupaten Nunukan dengan 4 perlakuan umur panen yaitu: 30 hari, 35 hari, 40 hari, dan 45 hari dengan 3 kali pengulangan. Parameter yang diamati berupa kadar air, kadar abu, dan kadar sulfat. Hasil penelitian menunjukkan umur panen memberikan pengaruh nyata terhadap kadar air, kadar abu, dan kadar sulfat Alkali Treated Spinosum (ATS) Chips. Nilai rata-rata kadar air ATS chips yang dihasilkan berkisar antara 7,58 – 11,28%. Nilai rata-rata kadar abu ATS chips adalah 10,9% – 19,4%. Nilai rata-rata kadar sulfat ATS chips berkisar 24,9% – 28,9%.

Kata Kunci: Alkali Treated Spinosum, Kadar Abu, Kadar Air, Kadar Sulfat, Umur Panen

Nunukan Regency is located in North Kalimantan Province and directly borders Malaysia. The total area of Nunukan Regency is 14,263.68 km2, and the sea area up to 4 miles from the outer coastline is 1,408,758 km2 (Marine Affairs and Fisheries Office Nunukan District, 2012). Seaweed cultivation, particularly of the Eucheuma spinosum species, is found in this region, including on Sebatik, Island which borders Malaysia. Eucheuma spinosum is a seaweed species that can thrive in temperature conditions of 28-30°C with an average of 30°C. It has a salinity tolerance range of 32-34 ppt with an average of 33 ppt and prefers a moderately strong current condition of 0.34-0.41 cm/second, which helps to carry nutrients. The quality of dried seaweed is an important factor that can influence the characteristics of the extracted carrageenan. Factors that influence the quality of carrageenan include extraction method, type and concentration of solvent, and seaweed harvesting age. Determining the appropriate harvesting age can affect hig-quality carrageenan. This study aimed to determine the characteristics of Eucheuma spinosum based on different post-harvest seaweed treatments. Seaweed has the ability to produce functional compounds, one of which is carrageenan, which is categorized as a carrageenophyte. The potential carrageenophyte species is Eucheuma spinosum. The research was conducted in May 2022 in Nunukan Regency, the research data(moisture content, ash content, and sulfate content) were statistically processed using ANOVA at the 5% level using the SPSS application. If the results were significantly different, the Duncan test was used. Viscosity testing was analyzed descriptively. Moisture content testing was intended to determine the water content in Alkali Treated Spinosum (ATS) chips. The moisture content in ATS chips significantly affects their shelf life. Keywords: Seaweed Characteristics, Alkali Treated Spinosum