Phosphonate salts are the result of deprotonation of phosphonic acids, which are diprotic acids: Phosphonate esters are the result of condensation of phosphonic acids with alcohols. Several methods exist for the preparation of phosphonic acids and their salts.
1 Stir in the tomato sauce, tomato paste, vinegar, diced tomatoes, and brown sugar. Season with chili powder, Italian seasoning, and salt. Bring to a boil, reduce heat to low, and simmer 1 hour.  Mix the cornstarch and water, and stir into the salsa to thicken. Transfer salsa to sterilized jars, leaving 1/2 inch headroom, and seal. Process jars in a boiling water bath 15 minutes. Store unsealed jars in the refrigerator.
Cover the bowl with cling wrap and place in the fridge (make sure it's quite thick, mine was far too thin). In a large mixing bowl, add the flour, salt, sugar and mixed spice. Add the butter and rub the flour and butter together with your fingers until the mixture resembles fine breadcrumbs.