create active record in rails except particular key in hash

I am searching from quite a long time now and I cannot figure out how to create active record in rails with hash except particular key in the hash.

What I am currently doing is

  ingre = {:name => "pepper", :std_qty => 2, :quantity => 20}

  quantity = ingre[:quantity]
    ingre.delete(:quantity)
  ingredient = Ingredient.new(ingre)
  ingredient.save!

I do not have quantity column in my ingredients table, there are only name and std_qty. and I don't want to use delete because it is not very concise way. I know that there is some way where in we can avoid key quantity while building the object ingredient instead of deleting externally. can anyone tell me what it is