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​04 Acids​ Methods​

04-10.01 Phosphoric Acid—Qualitative Method

To determine the presence of phosphate salts in baking powders and baking chemicals. The phosphates are present in baking powders as the acid component, responsible for reacting with the bicarbonate source, causing carbon dioxide to evolve. Typical phosphates used are monocalcium phosphate (anhydrous and monohydrate), sodium acid pyrophosphate, sodium aluminum phosphate, dicalcium phosphate, and dimagnesium phosphate. In baking chemicals, such as dough conditioners and yeast foods, phosphates are used as nutrient sources and pH/buffering agents. Dough conditioners may contain calcium or ammonium phosphates.

04-11.01 Phosphoric Acid—Quantitative Method

To determine phosphate salts content in baking powders and baking chemicals, expressed as P2O5 and phosphoric acid. Typical phosphates used are monocalcium phosphate (anhydrous and monohydrate), sodium acid pyrophosphate, sodium aluminum phosphate, dicalcium phosphate, and dimagnesium phosphate. In baking powders, phosphates (as the acid component) react with the bicarbonate source and cause carbon dioxide to evolve. In baking chemicals such as dough conditioners and yeast foods, phosphates are used as nutrient sources and pH/buffering agents. Dough conditioners may contain calcium or ammonium phosphates.

04-14.01 Sulfuric Acid—Quantitative Method

To determine the sulfate content, expressed as sulfuric acid, in baking powders and baking chemicals. Sulfate compounds, including sodium aluminum sulfate, calcium sulfate, and aluminum sulfate, may be used in baking powders and baking chemicals as leavening acids and diluents.

04-20.01 Acetic, Butyric, and Lactic Acids in Rye Flour

Different species of yeast may produce different amounts of acetic and lactic acids. The ratio of these two acids affects the butyric acid flavor of sour dough rye bread. This method determines acetic, butyric, and lactic acids in rye flour.

04-21.01 Benzoic Acid

The presence of benzoic acid is related to use of benzoyl peroxide as a beaching agent. An excess of benzoic acid is an indication of too much use of benzoyl peroxide. Some countries do not import flour in which benzoic acid is present. This method determines amount of benzoic acid in flour bleached with benzoyl peroxide.

04-22.01 Citric and Isocitric Acids

Citric and isocitric acids, together with malic and tartaric acids, are responsible for the tartness of fruits and affect flavor and quality of food products containing fruit and fruit products. This method measures the amount of citric and isocitric acids in fruit and fruit products.

04-27.01 Tartaric Acid—Quantitative Method

To determine the free, combined, and total content of tartaric acid present in baking powders and baking chemicals. Tartaric acid, or cream of tartar, is used as leavening acid in baking powders and for pH adjustment and flavor enhancement in baked goods. Tartaric acid reacts with bicarbonates to cause release of carbon dioxide. Calculations are based on reactivity with potassium hydroxide and sodium hydroxide and solubility of cream of tartar in reaction mixture in terms of 0.1 N NaOH.

04-28.01 Free or Combined Tartaric Acid—Qualitative Method

To determine the presence of tartaric acid, either free or combined, in baking powders and baking chemicals, in the presence of phosphates. Tartaric acid, or cream of tartar, is used as leavening acid in baking powders and for pH adjustment and flavor enhancement in baked goods. Tartaric acid reacts with bicarbonates to cause release of carbon dioxide.