Ade Edmondson, Danielle Bux, Ms Dynamite and Linda Evans are the final four hopefuls left on the show, with the winner to be chosen by a public phone vote.
White said that he had sacked the ex-Blue Peter presenter, 48, because she had not gone on "enough of a journey" during her time in the kitchen.
"You're exactly the same as the day you arrived," said the chef. "There's no growth and that's why you're sacked."
Earlier this week, Turner's husband Grant Bovey became the second celebrity to be fired from the reality series.
Speaking about being reunited with her partner, she told The Sun: "It's great to be back in our home together.
"When Grant had gone I was really upset, but then I thought, I'm going to see him in few days and there are women saying goodbye to their husbands when they are going off to fight in Iraq."
She added: "I was disappointed. I'd have loved to have stayed to fight another day."
Turner backed former Dynasty star Linda Evans to win the show, arguing that she was making "a stand for the older generation".