Process and Models of Decalcification of Bighead Carp Scale by Hydrochloric Acid

Collagen is one of the important biological materials.Fish scale contains rich collagen.Extracting collagen from fish scale not only reduces the biological pollution but also receives good economic benefit.In this paper, based on the experimental results of single factor test made in our previous research work, the response surface method was used to further optimize the technical parameters for the decalcification of bighead fish scale and establish the process model and kinetic model.The results showed that the maximum calcium removal rate reached 86.61% under the optimal conditions of hydrochloric acid concentration 5.0%, decalcification time 45 min and liquid/solid ratio 21.65 and the maximum decalcification velocity reached 0.4932g/(L• min) under the optimal conditions of hydrochloric acid concentration 6.4%, decalcification time 10.16 min and liquid/solid ratio 10.23.The two models in the form of multiple regression were proved to be basically identical with the actual values and they can be used to predict the calcium removal rate and decalcification velocity under different operation conditions and the decalcification velocity corresponding to the calcium removal rate under same conditions,to adjust the operation parameters for gaining the expected calcium removal rate and decalcification velocity, and to control the production capacity of fish scale treatment and the quality and production output of collagen prepared by following collagen extraction from the decalcified fish scale.