The most common preservative used in meat processing industry is a pickling mix. Its main purpose is to prevent the growth of bacteria. The key ingredient here is sodium nitrate. If we merely salt the meat soon it will turn brownish grey and will not look appetising and will go bad because of the bacteria growing in it, unrestricted. The sodium nitrate content of the pickling salt keeps meat fresh for a long time, with no loss of flavour and attractive appearance.