Optimization of dry-salting technology for grass carp (Ctenpharyngodon idellus) by response surface method

Using the content of sodium chloride and salt-soluble protein in grass carp (Ctenpharyngodon idellus) muscle and the protein content in brine as indexes, the effect of different salting conditions (time, temperature and concentration of brine) on the quality of grass carp muscle were studied by single factor tests and response surface method. A multiple regression model was set up between the result of sensory evaluation and determined indexes in different dry-salting condition. The result showed that as follows:positive correlation between dry-salting factors such as time, temperature and concentration of brine and the content of sodium chloride in grass carp muscle as well as the protein content in brine. The dry-salting time and temperature affected the content of salt-soluble protein in grass carp meat. The model set up by response surface method showed regression equation fit well with experimental data, and the content of sodium chloride extremely significantly affects the sensory evaluation, followed by fermentation temperature and time. When the dry-salting time 6d, temperatue 9.3℃ and the concentration of sodium chloride added to 11.70%, Grass carp dried was best with the sensory evaluation. The result was basically corresponding to model prediction.