In this study, the effects of three different salting methods on extract loss of rainbow trout was investigated. A total of 120 rainbow trouts were divided into 4 equal groups. Fish of group A served as untreated control. In groups B and C, brine with 8 and 20% (w/w) sodium chloride was used for a period of 6 h and 45 min, respectively. In the third method  (group D), dry salting was run by inserting a salt layer with fish layer for a period of 12 h. The contents of moisture and total proteins between the control and treated groups were significantly different (P<0.05). Molecular weights of protein bands detected in salted trouts were 125, 110, 104, 88, 66, 63, 52,  41, 34, 32 kDa. The protein bands of 125, 110, 104 and 63 kDa density were not seen in samples taken from control rainbow trout.  According to  total proteins analysis results, salting fish with brine having 20% NaCl  was suited as salting method, as the amount of total protein contents of extract loss in this method was  found low.  In contrary, the  total protein content in extract  was higher for dry salting  method.

Key words: Chemical composition, Curing, Fish, Proteins, SDS-PAGE