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.
Canning the Salsa. 1  1. Pour the salsa into clean canning jars. Fill the jars to within a quarter inch (half a cm) of the rim. 2  2. Place the lids on the jars of salsa. Screw on the lid rings to make sure they stay put. 3  3. Place the jars in a large pot. Fill the pot with water until it covers the jar by 2 inches (5 cm). Turn the burner to high heat and bring the water to a boil. If you live at low elevation, boil the jars for 15 minutes. If you live at high elevation, boil the jars for 25 minutes.