Characteristics of seaweed caraginan Kappaphycus alvarezii on cultivation system with different seed weight

Seaweed (Kappaphycus alvarezii) could be a source of carrageenan needed for industrial sector. The purpose of this study to analyze the characteristics of carrageenan seaweed cultivated with bag and non-bag cultivation systems and different seed weights. The research was conducted in the waters of Bone Bay and the Laboratory of the Indonesian Center for Brackish Water Cultivation and Fisheries Extension in Maros. This study used a factorial completely randomized design (CRD) consisting of factor A (using bags and non-bags), and factor B (seed weight 15, 50, 75, 100, and 125 g). The results showed that the cultivation method factor, seed weight factor, and their interaction had an effect on carrageenan yield, gel strength, ash content and water content (P <0.05). Different cultivation systems with different initial seed weight combinations showed different best results for each parameter. The highest value of yield of carrageenan was observed in the bag culture system with a seed weight of 100 g, namely 29.18 ± 1.10%. The highest value of gel strength was observed in the non-bagged cultivation system with a seed weight of 75 g, namely 1344.69 ± 18.43 g/cm2. The highest value of ash content was found in the non-bagged cultivation system with 125 g of seed weight, namely 30.02 ± 0.13%. The highest value of water content was found in the bag culture system at a seed weight of 15 g, namely 38.63 ± 0.26%. Different cultivation methods and seed weight resulted in other carrageenan characteristics of seaweed for each parameter.   Keywords: gel strength, ash content, moisture content, yield   ABSTRAK   Rumput laut (Kappaphycus alvarezii) memiliki potensi sebagai sumber karaginan yang banyak dibutuhkan untuk bidang industri. Penelitian ini bertujuan untuk menganalisis karakteristik karaginan rumput laut yang dibudidayakan dengan sistem budidaya kantong dan non kantong serta berat bibit yang berbeda. Penelitian dilaksanakan di perairan Teluk Bone dan Laboratorium Balai Riset Budidaya Air Payau dan Penyuluhan Peikanan Maros. Percobaan penelitian dilakukan melalui rancangan acak lengkap (RAL) faktorial yang terdiri faktor A (memakai kantong dan non kantong), faktor B (berat bibit 15, 50, 75, 100, dan 125 g). Hasil penelitian menunjukkan bahwa faktor metode budidaya, berat bibit dan interaksi keduanya berpengaruh terhadap rendeman karaginan, kekuatan gel, kadar air, kadar abu (P<0,05). Penggunaan sistem budidaya yang berbeda dengan kombinasi berat awal bibit berbeda menunjukkan hasil terbaik yang tidak sama pada tiap parameter. Nilai tertinggi rendeman keraginan teramati pada sistem budidaya kantong dengan berat bibit 100 g yakni 29,18 ± 1,10 %. Nilai tertinggi kekuatan gel teramati pada sistem budidaya non kantong dengan berat bibit 50 g yaitu 1344,69 ± 18,43 g/cm2. Nilai kadar abu tertinggi pada sistem budidaya non kantong dengan berat bibit 125 g yaitu 30,02 ± 0,13%. Nilai kadar air tertinggi pada sistem budidaya kantong dengan berat bibit 15 g yaitu 38,63 ± 0,26 %. Penggunaan metode budidaya dan berat bibit yang berbeda menghasilkan karakteristik karaginan rumput laut yang berbeda pada tiap parameter.   Kata kunci: kekuatan gel, kadar abu, kadar air, rendemen