Sodium bicarbonate, commonly known as baking soda, is ubiquitous in the food and nutrition industry. Its unique chemical properties make it an indispensable ingredient in various formulations. This article aims to provide a comprehensive overview of sodium bicarbonate, focusing on its production, applications, and role in food and nutrition products. It is tailored for chemists developing and optimizing formulations that incorporate this compound.
What is Sodium Bicarbonate?
Sodium bicarbonate, or baking soda, is a chemical compound with the formula NaHCO3. It is a white crystalline powder that is commonly used in cooking. It is primarily used as a leavening agent. When combined with an acid, it produces carbon dioxide gas, which causes a rise in the volume of the food matrix. This makes it a key ingredient in bakery and widely used in food products like cakes, cookies, and breads. Thus, the name baking soda.
Source: Wikipedia
Sodium bicarbonate is an inorganic compound and a weak base. It comprises sodium ion (Na+) and bicarbonate ion (HCO3-). When dissolved in water, it dissociates into these ions, interacting with other cations or anions to provide the desired effect. The chemical structure of sodium bicarbonate is given below.
How is Sodium Bicarbonate Produced?
The Solvay process is principally used for the synthesis of sodium bicarbonate. Sodium chloride, ammonia, water, and carbon dioxide are reactants. Sodium bicarbonate precipitates when carbon dioxide is bubbled through ammonia brine [1]. The process results in the formation of sodium bicarbonate and ammonium chloride. The sodium bicarbonate is then purified and crystallized. This method is favored for its efficiency and minimal environmental impact, making sodium bicarbonate readily available and cost-effective for industrial use.
Natural Source
Nahcolite is the natural mineral source of sodium bicarbonate. It is significantly found in Eocene-age Green River Formation deposits in Colorado’s Piceance Basin. It is mined from the deposits.
Use of Sodium Bicarbonate in Food and Nutrition
In the food industry, sodium bicarbonate is critical in many applications. Its primary use is as a leavening agent in baked goods, where it reacts with acidic components to release carbon dioxide, helping the dough rise and achieve the desired texture. However, its utility extends to pH regulation, flavor enhancement, and even as a component in effervescent beverages. Understanding the breadth of its applications is essential for chemists creating innovative and effective food products.
| Function | Details |
| Leavening agent/Raising agent | It is one of the most common uses of sodium bicarbonate. When combined with an acid, such as cream of tartar, it produces carbon dioxide gas, which causes dough or batter to rise. When heated above 100-120 °C, it decomposes into potassium carbonate and water and liberates carbon dioxide, thus increasing the volume of high-temperature processed goods. |
| Effervescent | Combination with acid liberates carbon dioxide, which creates effervescence in beverages. |
| Acidity regulator | It is a weak base and can act as a buffer, helping to maintain the pH balance in various substances. |
| Antacid | Potassium bicarbonate is also used as an antacid to relieve heartburn and indigestion. It works by neutralizing excess stomach acid. |
Applications in Food and Nutrition
| Type | Examples |
| Bakery | Cake, Bread, Cookies, Tortillas, Pizza, Muffins, Crackers |
| Snacks & Savory | Waffles, Pancakes |
| Soft drinks | Flavored beverages, Effervescent beverage tablets |
| Convenience | Cake premix, Dough mixes, Powdered beverages, Batters, |
| Meat | Processed meat |
| Infant food | Infant formulae |
| Chocolate & Confectionery | Hard candies, Chocolates, Chewables |
Properties of Sodium Bicarbonate
Chemically, sodium bicarbonate is a weak base and is a buffer in acidic environments. This property is crucial in maintaining pH balance in food products. It is also heat-stable, making it suitable for cooking and baking.
| Physical Form | Crystalline powder |
| Color | White |
| Odor | Odorless |
| Taste | Slightly bitter/alkaline taste |
| Storage Temperature & Conditions | Ambient temperature in closed container |
| Molecular Weight | 84.007 g/mol |
| pH (0.1 M) | 8.3 |
| Density | 2.20 g/cc |
| pKa | 6.3 |
| Solubility | 100 mg/L (25 °C) |
| Claims (*Product Specific) | Halal*, Kosher*, Vegan, Natural* |
Typical Formulations
Pound Cake
Here is an example formulation table:
| Ingredient | Composition (g) |
| Flour | 171.46 |
| Granulated sugar | 180.49 |
| Shortening | 87.23 |
| Salt | 4.54 |
| Wheat starch (Gelatinized) | 4.54 |
| Vanilla flavoring | 2.63 |
| Baking soda (Granulated) | 1.13 |
| Sodium acid pyrophosphate | 1.04 |
| Coated monocalcium phosphate | 0.54 |
Sodium bicarbonate is used as a leavening agent in this formulation, along with acid from sodium acid pyrophosphate.
Source: Google Patents
Baking Powder
Here is an example formulation table:
| Ingredient | % Composition |
| Sodium bicarbonate | 30 |
| Sodium aluminum sulphate | 20 |
| Monocalcium phosphate | 8.7 |
| Calcium sulphate (anhydrous) | 14.2 |
| Cornstarch | 27.1 |
The combination baking powder employs sodium bicarbonate with both SAS and MCP, which makes it a double-acting baking powder because of its ability to liberate carbon dioxide in the batter and baking stages.
Source: Google Patents
Ice Cream
Here is an example formulation table:
| Ingredient | Composition (g) |
| Milk cream | 59.2 |
| Skim milk powder | 30.2 |
| Sugar | 37.9 |
| Carboxymethyl cellulose | 0.93 |
| Egg yolk | 5.9 |
| Water | 165.9 |
| Baking soda | ~1.8 (0.6%) |
The addition of baking soda to ice cream improved the viscosity and overrun. It maintained the pH of ice cream in the neutral range. It also made the texture of the ice cream softer and creamier due to the small cavities from CO2 bubbles that weaken the bonding between ice crystals and other ice cream materials such as fat, sugar, and protein.
Source: ResearchGate
Effervescent Tablet
Here is an example formulation table:
| Ingredient | Composition (mg) |
| Potassium citrate | 2700 |
| Citric acid | 850 |
| Sodium bicarbonate | 750 |
| Mannitol | 60-120 |
| Fruit flavoring | 4.4-8.8 |
| Sodium benzoate | 10 |
| PEG 6000 | 30 |
These tablets were prepared by compressing the active ingredients with sodium bicarbonate and organic acid such as citric acid. This combination provides effervescence.
Source: NIH
Sodium Bicarbonate Formulation Considerations
| Physical Forms | Powder |
| Stability | – Temperature: Decomposes above 108 °C. – pH: Stable |
| Sensory Attributes | Odorless white powder with slightly bitter taste |
| Dosage | 0.5 – 1.5 % or more depending on the application |
| Interaction with Other Components | Reacts with acids in the food matrix |
Effect on Properties of Food
| Property | Effect |
| Volume | Sodium bicarbonate when reacted with acids or via thermal decomposition liberates carbon dioxide. This aeration causes an increase in the volume of the food matrix. |
| Texture | The aeration caused by sodium bicarbonate makes the food smooth, fluffy, and comparatively lighter. It can also bring about effervescence in liquid formulations. |
| pH | Sodium bicarbonate affects the pH of the food added to it. It is basic and thus causes an increase in the pH. |
| Shelf life | Sodium bicarbonate affects the pH of the food matrix, thus improving its shelf life. It also has reported antimicrobial activity. In a study, sodium bicarbonate improved the shelf life of Kinnow fruits and extended it to up to 75 days from 30 days in specific conditions [2]. |
| Freeze-thaw tolerance | Sodium bicarbonate improved the freeze-thaw tolerance of frozen dough and reduced the extractable protein proportion and free sulfhydryl level [3]. |
Sodium Bicarbonate vs Potassium Bicarbonate
Sodium bicarbonate is commonly used as baking soda. Potassium bicarbonate is generally a component of baking powder. Both have almost equal strength. The pH of sodium bicarbonate in 1% aqueous solution is ~8.5.
In contrast, the pH of potassium bicarbonate is ~8.3-8.4 in 0.1 M aqueous solution. Potassium bicarbonate is a sodium-free alternative to sodium bicarbonate for low-sodium food formulations. Potassium is also an important nutrient and electrolyte.
Safety and Regulatory Considerations
| FDA Information | Sodium bicarbonate is listed as a direct food additive under the Code of Federal Regulations (CFR) Title 21, Part 184. Sodium bicarbonate is generally recognized as safe when used per good manufacturing practices [4]. |
| EU Information | In the European Union, sodium bicarbonate is regulated by the European Food Safety Authority (EFSA) and is approved as a food additive under the code E500. It is listed in the EU’s food additives database with specific conditions of use and maximum permitted levels. |
Safety and Toxicity of Sodium Bicarbonate
Sodium bicarbonate, or baking soda, is generally considered safe for consumption and has a long history of use in food. Ingesting small amounts of sodium bicarbonate as a food ingredient or antacid is generally safe for most people. However, consuming large amounts or using it excessively can lead to adverse effects.
Sodium bicarbonate acts as an antacid by reacting with stomach acids when consumed.
However, there are many concerns raised regarding its excessive use as an antacid. It can lead to metabolic alkalosis or even cardiovascular health issues.
Identification Numbers
| IUPAC Name | sodium; hydrogen carbonate |
| CAS Number | 144-55-8 |
| EC Number | 205-633-8 |
| INS No. (Food Additive) | INS 500 (ii) |
| E Number (Food Additive) | E 500 (ii) |
Acceptable Limits or Maximum Usage
Regulatory bodies like the FDA and EFSA provide guidelines on the maximum permissible levels of sodium bicarbonate in various food products. Adhering to these guidelines is crucial for the safety and acceptability of food products in the market.
The acceptable daily intake (ADI) is proscribed by the WHO as “not limited” [5].
The maximum usage level of Sodium bicarbonate in the food industry per the GSFA is as follows [6].
| Food Category | Max Level |
| Fermented milk (plain), heat-treated after fermentation | GMP |
| Pasteurized cream (plain) | GMP |
| Sterilized and UHT creams, whipping and whipped creams, and reduced fat creams (plain) | GMP |
| Dried whey and whey products, excluding whey cheeses | GMP |
| Butter | GMP |
| Fresh pasta and noodles and like products | GMP |
| Dried pasta and noodles and like products | GMP |
| Frozen battered fish, fish fillets, and fish products, including mollusks, crustaceans, and echinoderms | GMP |
| Infant formulae | 2000 mg/kg |
| Follow-up formulae | GMP |
| Formulae for special medical purposes for infants | 2000 mg/kg |
| Complementary foods for infants and young children | GMP |
| Coffee, coffee substitutes, tea, herbal infusions, and other hot cereal and grain beverages, excluding cocoa | GMP |
| Herbs and spices | GMP |
Fun Facts About Sodium Bicarbonate
- French chemist Nicolas Leblanc first isolated sodium bicarbonate in the 1790s. The leavening process and related applications in bakeries were later introduced in the 18th century by John Dwight and Austin Church in New York.
- Sodium bicarbonate has been used since ancient times. The ancient Egyptians used a substance called natron, which contained sodium bicarbonate, for cleaning and as a soap-like material.
- Beyond baking, sodium bicarbonate is used for many household purposes. It’s a natural cleaning agent, effective for deodorizing fridges and carpets, and can be used as a gentle abrasive for scrubbing. It’s also popular in DIY personal care products, like toothpaste and deodorant.
- Sodium bicarbonate is a component of some fire extinguishers, especially those used for grease and electrical fires. When heated, it releases carbon dioxide, which helps to smother the flames.
- It has been used as an antacid to treat heartburn and acid indigestion. In more critical medical situations, sodium bicarbonate can treat certain types of acidosis.
- Athletes have used sodium bicarbonate as a legal performance enhancer. It can buffer lactic acid build-up in muscles during intense exercise, potentially improving endurance.
- In baking, it reacts with acidic components (like vinegar, yogurt, or lemon juice) to produce carbon dioxide gas, which helps baked goods rise and become light and fluffy.
- Sodium bicarbonate is eco-friendly compared to many chemical cleaners. Its non-toxic nature makes it a safe and green choice for household cleaning.
- A paste made from sodium bicarbonate and water can be applied to insect bites and stings to help alleviate itching and irritation.
- The oldest known deposit of nahcolite (the natural form of sodium bicarbonate) is in the Green River Formation in Colorado, which is believed to be about 50 million years old.
- Sodium bicarbonate plays a role in the carbon cycle. It acts as a buffer in bodies of water, helping to maintain a stable pH and thus supporting aquatic life.
