Abstract: In order to increase the decalcification rate extracted from grass carp scales, the technology parameters were optimized. Through dualquadratic rotary regression orthogonal design test with three factors, the effects of ratio of liquid to material, hydrochloric acid concentration and test time on the decalcification rate were assayed, so a mathematical model describing the relationship between the decalcification rate and parameters was developed. The optimal extracting conditions are as follows: ratio of liquid to material 57.67, hydrochloric acid concentration 3.81 % and extracted time 32.33 h with the decalcification rate 87.62%.

Key words: fish scale, decalcification, response surface method (RSM)