Optimasi perlakuan alkali dalam upaya peningkatan kualitas agar dari rumput laut

Agar is a hydrophilic colloids extracted certain marine algae of the class Rhodophyceae. Agar is strongly gelling Seaweed hydrocolloid composed of polysaccharides. The main structure of agar is chemically characterized by the repeating units of D-galactose and 3, 6-anhydro-L-galactose with a few variations, as well as by a low ester sulp,hate content. The qualities of Agar depend of alkali treatment process. The experiment is alkali treatmen ;ess of Agar extraction from Gracilaria sop. The variation of temperature for cooked was 70°C and 80°C. Th ation of sodium hydroxide solution was 3, 6, 8, 10% and for control without sodium hydroxide. The yield o ir in this experiment was increased by temperature, but not significant by sodium hydroxide solution. Th tent of 3,6 anhydro galactose was increased but the sulphate ester group was decrease when the seaweed o, cilaria was treated by increased the temperature and concentrations of sodium hydroxide. The gel strength ir was enhanced significantly by increased the sodium hydroxide solution but not by temperature. The nativ ir or Agar without alkali solution was observed that yield of Agar was 8,26% at 70°C and 6.58% at 80° tent of 3,6 anhydro galactose (AG) was 20,49% at 70°C and 33,12 at 80 °C, gel strength was 53.5 at 70 ° I 59,5 at 80°C, sulphate ester group was 6,26 at 70°C and 5,44 at 80°C. After alkali treatment: yield of Ag 3 varied from 8,25% to 11,76% at 70°C and 6,58% to 8,12% at 80°C; 3,6 AG was varied from 20,49% to 50,4 '0°C and 33,12% to 52,22% at 80°C; Gel strength was varied from 53,5 to 546,5 gram/cm' at 70°C and 59, 149,5 gramlcm2 at 80°C; sulphate was varied from 2,74% to 6,26% at 70°C and 2,42% to 5,44% at 80°C. Th imal condition was obtained in treated with 10% NaOH solution concentration at 70°C or 8% at 80°C.