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7446-19-7
futurechem
7446-19-7
project | information |
Chinese name | Zinc sulfate monohydrate |
English name | Zinc sulfate monohydrate |
Molecular formula | ZnSO₄·H₂O |
molecular weight | 179.49 |
CAS number | 7446-19-7 |
Appearance | White, free-flowing powder or granules, odorless |
Solubility | Very soluble in water (aqueous solution is weakly acidic), slightly soluble in ethanol |
Zinc sulfate comes in two common food-grade forms:
form | Molecular formula | CAS | Zinc content | Appearance | Applications in food fortification |
Monohydrate (the main character in this article) | ZnSO₄·H₂O | 7446-19-7 | ~36% | White powder | The preferred form for flour and grain fortification – high zinc density, less prone to clumping. |
heptahydrate | ZnSO₄·7H₂O | 7446-20-0 | ~22% | Colorless or white crystals | High moisture content – prone to clumping in dry powder foods; low zinc content – high fortification costs. |
This is the sector with the largest global consumption of food-grade zinc sulfate.
reinforcement strategy | Zinc addition (as Zn) | Zinc source |
WHO Recommendation - Flour Fortification | 30~70 mg/kg flour | ZnSO₄·H₂O is the preferred choice, while ZnO is an alternative. |
US CSB/WSB Rescue Food | 50~80 mg/kg product | ZnSO₄·H₂O (USDA Designated) |
China GB 14880 - Flour | ≤ 80 mg/kg (permissible range) | ZnSO₄ or ZnO or zinc lactate |
Zinc sulfate vs. zinc oxide: The battle between the two major zinc sources in flour fortification
There are two main options for zinc fortification: zinc oxide (ZnO, insoluble in water, white) and zinc sulfate (ZnSO₄, soluble in water). The WHO's position is that zinc sulfate is the preferred option, while zinc oxide is an alternative.
contrast | Zinc sulfate monohydrate | Zinc oxide |
Zinc content | ~36% | ~80% |
Water-soluble | High – Zn²⁺ direct free release | Insoluble – It needs to dissolve in stomach acid before it can be absorbed. |
Bioavailability | high | Medium (depending on stomach acid levels and particle size) |
Sensitivity to phytic acid | Sensitive – Phytic acid in whole wheat flour can chelate Zn²⁺, reducing its absorption. | Relatively insensitive (gradual dissolution and release) |
Effects on food color | None (white) | None (white) |
cost | Low (higher than ZnO) | lowest |
Infants and young children have a need for zinc throughout their rapid growth period—zinc is an essential cofactor for DNA synthesis and cell division. Zinc fortification in infant formula and rice cereal usually uses zinc sulfate as the inorganic zinc source (sometimes combined with organic zinc such as zinc lactate or zinc gluconate to enhance the "natural" image of premium products).
Among various multi-element tablets, zinc sulfate is the most common inorganic zinc source—because:
● White – does not alter the appearance of the tablet;
● High zinc content—one tablet contains 5-15 mg of zinc, requiring only tens of milligrams of zinc sulfate;
● It is physically compatible with other minerals (calcium, magnesium, iron) in solid tablets.
Zinc sulfate is a standard source of zinc in protein powders, meal replacement powders, and sports nutrition products. Its solubility ensures that zinc ions are evenly distributed in the liquid after preparation, unlike zinc oxide which tends to settle at the bottom.
Zinc Sulfate Monohydrate (CAS 7446-19-7) is the most fundamental building block in the global food zinc fortification supply chain:
Scene | What did it do? |
North American flour mills | Sprinkled into tons of flour—making every slice of toast a zinc carrier. |
African aid food | Precisely weighed into the CSB formula—adding a boost of zinc to the growth of malnourished children. |
Infant formula factory | The chemical starting point for the first gram of zinc in life, added to the mineral premix of infant formula. |
Sports nutrition can | Dissolve it in protein powder—so every smoothie after a weightlifting session contains zinc. |
It doesn't pursue taste (that's the track for zinc lactate and zinc gluconate), nor does it pursue the highest zinc content (that's the track for zinc oxide), but it pursues covering the largest population at the lowest cost on the scale with the greatest impact on human nutrition—global staple food fortification.
