The Quality Characteristics of Soy Wan-Jas Made with Different Proteolytic Enzyme Treated Textured Soy Proteins

Abstract

This study examined the solubility, emulsifying activity, and electrophoresis patterns of textured soy protein (TSP) treated with different enzymes and enzyme hydrolysis times, along with the quality characteristics of soy wan-jas made from the different enzyme treated TSP. Solubility and emulsifying activity were greater in a Protamex® 20 minute-treated group compared to a Flavourzyme® 20 minute-treated group. With regard to electrophoresis patterns, 11S globulins were decomposed by the Protamex® treatments but not by the Flavourzyme® treatments. The cooking yields of the soy wan-jas were higher than those of beef wan-ja. Furthermore, the cooking yields of the Flavourzyme® treated groups were higher than those of the Protamex® treated groups, and cooking yields increased as hydrolysis time increased. When the wan-jas were cooked, the beef wan-ja had a higher percent reduction in diameter compared to the soy wan-jas, but the thickness of the beef wan-ja was greatly increased. The chewiness of the soy wan-jas was higher than that of the beef wan-ja, since the soy wan-jas had higher cohesiveness and springiness and lower hardness. The flavor, chewing property, and overall quality of the Flavourzyme® 20 minute-treated group were similar to those of the beef wan-ja. The Protamex® treated groups, however, were evaluated as being the least desirable. In conclusion, Flavourzyme® treatment for 20 minutes increased the solubility and emulsifying activity of textured soy proteins, but did not decompose 11S globulins. Thus, the cooking yields of the soy wan-jas increased, percent reductions in diameter and thickness were low, and texture and sensory characteristics were improved.