PENGARUH ENZIM POLIGALAKTURONASE DAN GELATIN DALAM KLARIFIKASI SARI BUAH NAGA SUPER MERAH (Hylocereus costaricensis)

Abstract

The aimed of this research was to determine the effect of polygalacturonase (PG) enzyme from Bacillus licheniformis strain GD2A AR2 (0.09% and 0.1%) with gelatin (1% and 1.5%) in super red dragon fruit juice clarification against to pH, total soluble solids, viscosity, and transmittance. Polygalacturonase enzyme hydrolyze pectin into galacturonic acid that it may reduce the pH and viscosity of super red dragon fruit juice. Decrease in pH caused the decrease of total soluble solids of super red dragon fruit juice. Degradation of pectin increased transmittance of super red dragon fruit juice. Gelatin in fruit juice increased pH, total soluble solids, viscosity, and transmittance. Samples with polygalacturonase enzyme 0.1% , total soluble solid15.6667Brix, viscosity 10.3957cP, transmittance 0.8 (% T535), and the pH value of 3.97 were selected sample. Polygalacturonase enzyme 0.1% may reduced the value of total soluble solids, decreased viscosity values, increased the value of transmittance, and reduced the pH value of super red dragon fruit juice. Gelatin can clear the juice by absorbing the contents that can cause cloudy juice like tannins. Gelatin has an amino group that is able to form complex compounds by binding to pectin in fruit juice. This research was conducted into PG enzyme production, PG enzyme partial purification, variation of enzyme concentration and gelatin, super red dragon fruit juice clarification, and determination for the best treatment. Best pH value in the samples with polygalacturonase enzyme 0% and 1.5% gelatin was 4.11 (control 4.8). The highest transmittance value in the sample with polygalacturonase enzyme 0.1% and 1.5% gelatin was 1 (% T535). Gelatin and polygalacturonase enzyme worked together in improving the transmittance value in the clarification super red dragon fruit juice simultaneously with increasing the used of concentration enzyme and gelatin.