It's mentioned in the linked to article: > Only two brands produced samples that were pure and nonoxidized. Those were Chosen Foods and Marianne’s Avocado Oil,

It's mentioned in the linked to article: > Only two brands produced samples that were pure and nonoxidized. Those were Chosen Foods and Marianne’s Avocado Oil, both refined avocado oils made in Mexico. Among the virgin grades, CalPure produced in California was pure and fresher than the other samples in the same grade