Dynamic continuous countercurrent extraction of collagen from the foot of Haliotis discus

In order to extract acid soluble collagen( ASC) from the foot of defective Haliotis discus,the process conditions of single- stage dynamic intermittent extraction and multi- stage dynamic continuous countercurrent extraction were investigated and compared. The results showed that the optimum conditions for single- stage dynamic extraction were as follows: acetic acid( 1 mol / L) / hydrochloric acid( 0.4 mol / L) 50%( v / v),solid to liquid ratio 1 ∶ 10,flow rate 40 m L / min,extraction time 1 h and extraction times 2. Under these conditions,the ASC extraction rate and ASC concentration reached a highest value of 11.2% and 1.04 mg / m L,respectively.Moreover,it was found that three- stages was the best condition for dynamic continuous countercurrent extraction and obtained a higher ASC extraction rate( 16.9%) and ASC concentration( 3.12 mg / m L). Based on these results,ASC was further purified by regulating ammonium sulfate concentration and p H value simultaneously. The highest ASC recovery ratio( 89.1%) and ASC purity( 88.4%) were obtained when ammonium sulfate concentration and p H value were controlled at 0.4 mol / L and 5.6,respectively.