“…Therefore, prediction model from RSM was promising technique feasible for application in Ca extraction from fish bone powder using citric acid. The RSM was also applied successfully to extract active calcium from Megalobrama Amblycephala and found the optimum extraction time for 0.8 h at 113 °C [ 32 ]. Our results provide more efficiency by shortening the extraction time to be 60 s due to application of microwave digestion.…”