Different techniques have been employed to improve the technological properties of meat. One of the most important techniques is adding proteolytic enzymes which could simultaneously increase the tenderization and solubility of meat proteins. The purpose of this investigation was to study the effect of different levels of the enzyme ficin on ovine and bovine meat and to determine the best condition for solubilization of meat proteins. Ficin was partially purified from figs tree latex by cationic exchange chromatography. Meat samples were treated wilh different activities of ficin and the effect ofenzyme was followed by measuring nitrogen solubility index (NSI) and electrophoresis. NSI was determined by homogenization of ficin-treated meat in the presence of buffers, centrifugation and nitrogen determination of the supernatant by kjeldal. The solubility of meat proteins increases with increase in the activity of added ficin and with increase in the incubation time (p<0.001). Presence of salt significantly increased the solubility of meat proteins up to 65% (p<0.01). The SDS-PAGE pattern of soluble proteins showed the molecular weight of proteins was in the range of 15-105 KDa and was similar in ovine and bovine meat. Also by increasing the unit activity of enzyme form 0.8 to 2.6 units. most protein bands were disappeared or decreased in intensity. These results indicated that the velry high activity of ficin results in disruption of the structure of myofibrillar proteins and excessive break down of these proteins to smaller peptides which either precipitate or can not be detected by electrophoresis.
Key words: Ficin, meat proteins, electrophoresis, nitrogen solubility index.