rails delete asociated items or better way how to update associated rows in child table

i am import feed and have two models product and images from feed hot i am try to firstly erase all associed fields but line record.Images.clear failed, can anyone give me hint

import code

def monditrade
    require "nokogiri"
require "open-uri"
doc = Nokogiri::XML(open("http://ift.tt/1lOiVqd"))

    doc.css('product').each do |node|
            children = node.children

            record = Product.where("supplier_link" => children.css('link').inner_text).first_or_initialize
            record.name=children.at("name").inner_text
            record.delivery=children.at('delivery_date').inner_text
            record.desc=children.at('description').inner_text
            record.desc_long=children.at('description2').inner_text
            record.supplier_name="monditrade"
            record.supplier_code=children.at("code").inner_text
            ean=children.at('ean')
            if ean
              record.ean=ean.inner_text     
            end

            record.manufacturer=children.at('manufacturer').inner_text
            record.supplier_code=children.at('code').inner_text
            record.supplier_category=children.at('category').inner_text

            record.Images.clear
            children.css('img').each do |node|
              image = Image.where("url" => node.inner_text.squish,"product_id"=> record.id).first_or_initialize
              image.save


            end
            record.save




            end

end

product.rb

class Product < ActiveRecord::Base
    has_many :Image
end

image.rb

class Image < ActiveRecord::Base
  belongs_to :Product
end

and in controller i am parse some xml feeed

example feeed

http://ift.tt/1lOiWul