Solubilization of onion with polysaccharide-degrading enzymes

For the selection of suitable enzymes for the solubilization of onion, degree of solubilization (DS) values were measured. The DS values of Pectinex and Viscozyme were 75.8 and 78.4%, respectively, which indicates they have higher specific activities than Cereflo and Celluclast. The enzyme mixture of Pectinex and Viscozyme (relative ratio of 1:3) had higher DS values and reducing sugar content than Pectinex alone. The enzyme mixture degraded onions with a synergistic effect, solubilizing 85% of the onion. The DS values and reducing sugar content at the optimal condition (pH 4.5 and 45 °C) reached a maximum of 85% and 494.8 mg g^-1 of onion, respectively. The DS values and reducing sugar content increased with increasing reaction time, reaching a maximum of 89% and 517.5 mg g^-1 of onion, respectively. When cooking pork, onion appeared to be preferable to onion hydrolysate, however there was no significant difference. The sweetness and preference of pork cooked with 3% addition of hydrolysate per gram of pork meat were the highest but those were not different significantly from those cooked with less than 10% addition of hydrolysate per pork meat.