Most are not effective above their pKa's. Most affect flavor. Most are affected by processing, order of addition. Broad spectrum against yeast and molds. In salad dressings, fruit juices, cottage cheese.
Potassium salt Is the most widely used form.
182.3640 Potassium sorbate. Most active against yeast and molds. Acid form relatively Insoluble and not used much. More effective against yeast and bacteria. Sodium diacetate used In some breads.