Sodium propionate is a food preservative permitted for use in accordance with China’s GB2760 – 2011 regulations. It is used in pastries, bean products, etc.; it can be used alone or in combination with propionic acid and sorbic acid; it can also be used as an inhibitor of viscous substances in beer, etc.; and as a feed additive, etc. Its appearance is colorless and transparent crystals or granular crystalline powder, with no odor or a slightly acetic-propionic-butyric acid odor. It is stable to light and heat, and is prone to deliquescence in humid air.

The main uses of sodium propionate as a preservative are as follows:

1. Sodium propionate is an acid-type food preservative, and its antibacterial effect is affected by the environmental pH value. In an acidic medium, it has a relatively strong inhibitory effect on various molds, Gram-negative bacilli, or aerobic spore-forming bacilli. It is effective in preventing the production of aflatoxin and is almost ineffective against yeasts. In the food industry, it can be used for the preservation of pastries, with a usage amount of 2.5g – – kg (calculated as propionic acid).

2. Cosmetic preservative. It has a broad antibacterial effect on molds, yeasts, etc. The antibacterial effect is particularly obvious in an acidic medium. The addition amount in cosmetics is usually not more than 2%.

3. Other uses such as being used as: an insecticide, an anti-mold agent, and as a masking agent in leather making to improve the alkali resistance and the uniformity of tanning of leather.

Sodium propionate is obtained by neutralizing propionic acid with sodium hydroxide or sodium carbonate. Propionic acid reacts with sodium hydroxide or sodium carbonate until the pH value is neutral, obtaining a sodium propionate solution. After decolorization, filtration, vacuum concentration, cooling filtration, spraying, and drying, the finished product is obtained. Although the ability of sodium propionate to inhibit molds is lower than that of calcium propionate, it does not affect the action of chemical leavening agents, so the application of sodium propionate in foods such as bread is more extensive than that of calcium propionate. Calcium propionate has good water solubility and is also relatively convenient to use.