Sodium ferrocyanide (decahydrate) is also called sodium ferrocyanide, and its chemical formula is Na4Fe(CN)6·10H2O. It is a cyanide salt used as an anti-caking agent in table salt to keep the salt flowing freely, with the European food additive number E535.
Given that it is cyanide salt, you might be surprised why this ingredient can be present in salt, and is it really safe? let's continue.
How is it made?
It is a synthetic compound that can be produced industrially, consisting of sodium cyanide and ferrous sulfate reacting in an aqueous medium under heating conditions, as shown in the following chemical equation:
6NaCN + FeSO4 + heating → Na4Fe(CN)6 + Na2SO4
After the crystallization process, sodium ferrocyanide decahydrate can be obtained.
It can also be obtained by the reaction of calcium cyanide, ferrous sulfate and sodium carbonate.
- CaCN2 + FeSO4 → Ca2Fe(CN)6 + CaSO4
- Ca2Fe(CN)6 + 2Na2CO3 → Na4Fe(CN)6 + 2CaCO3
characteristic
Yellow crystal or crystalline powder, the yellow color comes from ferrocyanide anion ([Fe(CN)6]4-), iron is in Fe2+ state.
| other names | Sodium hexacyanoferrate, tetrasodium hexacyanoferrate |
| CAS number | 14434-22-1 |
| chemical formula | Na4Fe(CN)6·10H2O |
| molecular weight | 484.1 |
| Solubility | Soluble in water, insoluble in ethanol |
Why is sodium ferrocyanide used in table salt?
Sodium ferrocyanide is a cyanide complex whose main use in food is as an anti-caking agent in human salt (table, sea, iodized and non-iodized salt). It's vegan and gluten-free.
Salt crystals easily dissolve on their surface after absorbing moisture in high-humidity air, and then recrystallize after the water evaporates. Finally, clumping, agglomeration, or aggregation occurs.
Some salts have a small amount of sodium ferrocyanide added to prevent clumping (or clumping) and reduce the amount of recrystallization by reducing the solubility of sodium chloride in water.
Is sodium ferrocyanide safe to eat?
First of all, please be assured that sodium ferrocyanide has almost no side effects when used as a food additive. Its safety has been recognized by the U.S. Food and Drug Administration (FDA), the European Food Safety Authority (EFSA) and the Joint Expert Committee on Food Additives (JECFA) of the United Nations Food and Agriculture Organization/World Health Organization. So please don't worry.
Safety concerns are often caused by the presence of cyanide, a known toxin, in its chemical name.
As you can imagine, many consumers may be horrified if they see ferrocyanide (a cyanide complex) listed on a salt label, which is why most salt manufacturers prefer to It's labeled "yellow soda."
Many cyanide salts are hazardous, but the cyanide in food-grade ferrocyanide is nontoxic because it is tightly bound to the iron atoms and therefore does not release free cyanide.
In an acidic environment, the bond between sodium and ferrocyanide will break, releasing a toxic gas - hydrogen cyanide gas. However, stomach acid is a weak acid and cannot promote this reaction in our bodies.
If you're still afraid of this ingredient, you can turn to other anti-caking agents commonly found in table salt, such as silica, sodium aluminosilicate, and calcium silicate.
U.S. Food and Drug Administration
Sodium ferrocyanide acts as an anti-caking agent in salt and as an auxiliary in the production of dendrites. The maximum addition amount is 0.0013%, based on anhydrous sodium ferrocyanide.
It is also safe to use as an anti-caking agent in animal feed salts.
European Food Safety Authority
Sodium ferrocyanide (E535) is listed in Commission Regulation (EU) No 231/2012 as an authorized food additive and classified as "additives other than colorings and sweeteners".
The ferrocyanides (potassium ferrocyanide, sodium ferrocyanide and calcium ferrocyanide) are only approved for use in salts and salt substitutes, alone or in mixtures, at a maximum concentration of 20 mg/kg (as anhydrous Potassium ferrocyanide calculation).
2018 Safety Re-evaluation
EFSA concluded in its 2018 safety reassessment report that there were no safety concerns with the current authorized use and use levels of sodium ferrocyanide.
Here are some key points:
- Human body absorption is low and there is no accumulation.
- Non-genotoxic and non-carcinogenic.
- Considering that the only toxicity of ferrocyanide ions is to the kidneys, the acceptable daily intake (ADI) was determined to be 0.03 mg/kg bw (expressed as ferrocyanide ions).
joint expert committee
Functional categories: food additives, anti-caking agents.
Acceptable Daily Intake: ADI "0-0.025 mg/kg bw" set in 1974.
in conclusion
Now you probably know about the production process of the food additive sodium ferrocyanide or sodium ferrocyanide (E535); its role in table salt; its approved safety; where the health concerns come from and the safety of cyanide in it sex.
What do you think of this anti-caking agent? Please tell me in the comments.
