Characteristic of semisolid isinglass from catfish (Pangasius sp.) swimbladder based on different concentration in acetic and citric acid solution

Catfish culture is currently being developed in Indonesia. Fishing industry produce waste, such as swim bladder, which is potential for production of edible coating and fining agent. This research aims to analyze semisolid isinglass characteristics (pH, moisture, protein, fat, ash, proline and glycine content). Catfish swim bladder was soaked in acetic and citric acid solution with concentration of 1%, 1.5% and 2%, respectively. Result of analysis showed that, the semisolid isinglass soaked in acetic acid solution had average pH between 2.41-2.69, moisture between 98.97%-99.08%, 0% ash content, fat ranging between 0.20%-0.21%%, protein between 0.49%-0.53%, proline between 462.82 ppm-605.88 ppm and glycine between 1069.35 ppm-1163.08 ppm. The semisolid isinglass soaked in citric acid solution had average pH between 1.75-1.94, moisture between 97.62%-98.55%, 0% ash content, fat between 0.00%-0.47%, protein between 0.11%-0.20%, proline ranged between 377.49 ppm-469.63 ppm and glycine ranged between 964.07 ppm-1056.26 ppm. Based on statistical analysis, all concentration from both acids showed significant effect on pH value and moisture content.