In the 18th century and earlier, bakers relied on yeast to ferment all baked goods. However, using yeast to ferment baked goods was tedious, and bakers began to explore the use of chemical fermentation systems. In 1846, people found baking soda as a leavening agent, which led to the discovery of acids that reacted with baking soda. This led to the emergence of Sodium acid pyrophosphate baking powder.
Sodium acid pyrophosphate (SAPP) is an important ingredient in double-fermented and self-expanding flours.SAPP reacts in stages and is desirable in baking applications due to its slow action.
Type of Baking Powder Baking powder is also categorized into slow-reaction baking powder, fast-reaction baking powder and dual reaction baking powder according to the different reaction speeds. Fast reaction baking powder starts to work when dissolved in water, while slow reaction baking powder starts to work during the baking and heating process, of which double reaction baking powder has the reaction characteristics of both fast and slow baking powder. Generally, the baking powder purchased in the market are all double reaction baking powder. Dual reaction baking powder contains two acidic materials, one of which reacts with baking soda at low temperatures, while the other reacts completely with baking soda during baking, so dual reaction baking powder provides carbon dioxide at two different temperatures.
II. Chemical reaction mechanism
The low solubility of sodium acid pyrophosphate in cold water allows it to be used as a baking powder for chronic reactions. When moisture is added to form the dough, SAPP reacts with baking soda (sodium bicarbonate) to produce carbon dioxide gas. During the initial two minutes of mixing, 22-40% of the gas is released. When heated during baking, the remaining gas is released, over 50%.
The reaction formula are as following:
Na2H2P2O7 + NaHCO3 → Na3HP2O7 + CO2 + H2O
Na2H2P2O7 + 2NaHCO3 → Na4P2O7 + 2CO2 + 2H2O
III. Advantages:
SAPP dissolves readily to form an anionic pyrophosphate which interacts with proteins in well-baked systems to provide a moist texture.
The anion provided by SAPP, in combination with cations such as calcium ions, increases the toughness of the batter proteins, improves the organization of the baked product tissue particles and each of the air chambers, stops the air chambers from sticking together, and results in a finely organized and elastic baked product.
SAPP is a preferred leavening acid because it is cheaper and stronger than other previously introduced leavening acids.
IV. Disadvantages:
The use of sodium acid pyrophosphate-containing baking powder must be balanced between acid and alkali. The slight overdose with residual sodium pyrophosphate will lead to a bitter taste, which can of course be overcome by the addition of calcium-containing compounds such as calcium lactate.
V. Baking Powder Recipes for the Baking Industry
Baking soda
monocalcium phosphate
sodium acid pyrophosphate
calcium lactate
corn starch
Recipe A
30%
5%
36%
2%
27%
Recipe B
30%
–
42%
–
28%
VI. Commercial production
Food grade sodium acid pyrophosphate is manufactured by partially neutralizing food grade phosphoric acid with sodium hydroxide or sodium carbonate to form monosodium phosphate. Dehydration of monosodium phosphate at 250°C will form sodium acid pyrophosphate (SAPP).
Currently, there is no known natural method of producing SAPP.
VII. Suitable Bakery Products
Sodium acid pyrophosphate (SAPP) is slow acting and does not react quickly with baking soda, making it the most commonly used self-expanding flour leavening acid for home bakers.
Because SAPP can have a slight bitter flavor, it is important to use enough baking soda to combine this leavening acid with sugary foods such as donuts and cakes. Cake donuts are an important application for SAPP where initial gas generation is necessary for buoyancy in the frying system. In addition, SAPP is useful for cakes where initial gas production is necessary for pan-filling consistency.
Other non-bakery applications of SAPP include its use as a chelating agent for processed potatoes, an emulsifier for cheese, and a curing accelerator for processed meats.
VIII.Conclusion
Sodium acid pyrophosphate holds significant importance in the baking powder. It offers slow reaction acid during the fermentation, and because of its advantages it is suitable for cake and donuts making.
The use of this baking powder is recognized as harmless and beneficial to food. Of course, we still need to be aware that SAPP alone cannot be used as baking powder, it needs to be used in conjunction with baking soda. Of course, when we buy baking powder, we need to make sure that it comes from a regular manufacturer that strictly adheres to food safety standards.
