Extraction of chondroitin sulfate from chicken keel cartilage by combined applicationof ultrasound treatment and alcalase hydrolysis

The optimal conditions were obtained by the Circumscribed Central Composite design method using the Modde 5.0 software. Optimal values for this process were found at pH9, ratio of material to buffer 1:9 (wmaterial/vbuffer), temperature 47.34 oC, and time within 9.2 minute. After ultrasound treatment, hydrolysis using the enzyme Alcalase was performed under the following conditions: ratio enzyme to substrate 4 % (v/w), temperature 55 oC, and time 60 minutes.