f you buy fresh octopus, you should boil it before searing it in a pan. Raw octopus contains a high amount of collagen that breaks into gelatin when near boiling. Hence, boiling is necessary to extract this gelatin into the water and then discard half of this water to reduce the amount of gelatin in the octopus. If this gelatin is not removed, a thick layer of purple goo will surround the octopus on pan frying.