Mineral acid used for sharp acidification
E338 phosphoric acid is orthophosphoric acid used as an acidulant and acidity regulator, most famously in cola-type beverages. It provides a sharp acid profile different from citric or malic acid and contributes phosphorus. Because it is a mineral acid rather than an organic fruit acid, its sensory and nutritional implications differ. In beverage systems it lowers pH, supports flavour balance, affects preservative efficacy and contributes to titratable acidity.
Phosphoric acid is part of the broader phosphate additive group evaluated by EFSA. Phosphate exposure should be expressed as phosphorus where required. Unlike organic phosphate naturally bound in foods, inorganic phosphate additives can be highly bioavailable. This is why phosphoric acid use should be controlled by technological need and total phosphorus exposure, especially in products consumed frequently.
Beverage function and formulation
In cola beverages, phosphoric acid gives a clean sharp acidity that works with caramel colour, caffeine, flavours and carbonation. The final pH influences microbial stability, preservative performance, sweetness perception and enamel-related consumer discussions. Dose should be set by flavour and pH target, not by copying a historic formula. If sugar is reduced or sweetener system changes, acid balance often needs redesign because sweetness and acidity interact strongly.
Phosphoric acid can also be used in processing where mineral acidification is desired, but concentrated material is corrosive and requires safe handling, compatible equipment and controlled dilution. Operators should add acid to water under validated procedures and prevent local low-pH damage to ingredients or equipment.
EFSA phosphate context
EFSA's 2019 phosphate re-evaluation established a group ADI of 40 mg/kg body weight per day expressed as phosphorus for phosphates from all sources. EFSA estimated dietary exposure across age groups and considered total phosphorus exposure, not only one additive. Open-access phosphate reviews emphasize that inorganic phosphate additives are often more readily absorbed than naturally bound phosphate and can be difficult for consumers to identify. That makes beverage phosphate documentation relevant beyond flavour.
Release and troubleshooting
Release should include acid strength, dose, final pH, titratable acidity, phosphorus contribution per serving, sensory result and package compatibility. If microbial stability fails, check pH, preservative system and sanitation. If flavour is harsh, balance sweetness, acid blend and carbonation. If precipitation or haze appears, review minerals, pH and water hardness. E338 is technically simple but commercially sensitive because it combines acidification, flavour and phosphorus exposure.
Operator controls
Operators should use controlled dilution, compatible equipment and PPE for concentrated phosphoric acid. In beverages, brix, carbonation and pH should be checked together because sweetness and CO2 change acid perception. Phosphorus per serving should be available for regulatory and nutrition review.
Product design examples
In cola concentrates, phosphoric acid must be evaluated with water alkalinity, sweetener system, caramel colour, flavour oils and carbonation. Small pH shifts can change microbial stability and flavour perception. In reduced-sugar cola, acid balance often needs redesign because sweetness no longer masks sharp acidity in the same way. In high-mineral waters, phosphate precipitation or haze may appear if calcium or magnesium are high.
Phosphoric acid is also a strong process chemical. Dilution order, temperature and equipment compatibility matter. Local low pH can damage ingredients before the batch is fully mixed. In a plant audit, the acid handling SOP should be as clear as the formula. The additive is food-grade in the final product, but concentrated phosphoric acid is corrosive during production.
Audit checklist
The E338 file should include pH, titratable acidity, phosphorus per serving, sensory acid target and preservative interaction. If the product is marketed to high-consumption groups, phosphate exposure should be reviewed. If a brand replaces phosphoric acid with citric or malic acid, sensory and preservative validation must be repeated because acid identity changes more than pH.
Change control
Phosphoric acid supplier change should include concentration, food-grade purity, heavy metals and packaging compatibility. In beverage plants, acid concentration must be verified because small strength differences can move pH and flavour. Water alkalinity changes can also affect final pH. A formula transferred to a new water source should recheck acid dose.
Exposure documentation should not ignore serving size. A cola concentrate may use a controlled acid level, but frequent consumption increases phosphorus intake. EFSA's group phosphate ADI is expressed as phosphorus, so the product file should convert E338 to phosphorus contribution. This makes the acidulant decision transparent to nutrition and regulatory teams.
Final release matrix
The final release matrix should include phosphoric acid concentration, final pH, titratable acidity, phosphorus per serving, sweetness-acid balance and package compatibility. In cola systems, carbonation changes perceived acidity, so sensory release should use finished carbonated product. If preservative efficacy depends on pH, microbial validation should use the end-of-life pH, not only the mixing-tank pH.
When E338 is reduced or replaced, the team should recheck flavour, pH, preservative performance and phosphorus declaration together. Matching pH with another acid does not guarantee the same cola profile or microbial hurdle.
Retain samples should include warm storage when the beverage is distributed unrefrigerated, because pH, carbonation and flavour perception can drift together.
Control limits for Food Additive E338 Phosphoric Acid
A reader using Food Additive E338 Phosphoric Acid in a plant or development lab needs to know which condition is causal. The working boundary is ingredient identity, process history, analytical method, storage condition and release decision; outside that boundary, a passing result can be misleading because the product may have been sampled before the defect had enough time to appear.
Additive E338 Phosphoric Acid: additive-function specification
Food Additive E338 Phosphoric Acid should be handled through additive identity, purity, legal food category, maximum permitted level, carry-over, matrix compatibility, declaration and technological function. Those words are not filler; they define the evidence that proves whether the product, lot or process is still inside its intended control boundary.
For Food Additive E338 Phosphoric Acid, the decision boundary is dose approval, label check, market restriction, substitute selection or supplier requalification. The reviewer should trace that boundary to assay, purity statement, formulation dose calculation, finished-product check, label review and matrix performance test, then record why those data are sufficient for this exact product and title.
In Food Additive E338 Phosphoric Acid, the failure statement should name wrong additive class, excessive dose, weak function, regulatory mismatch, undeclared carry-over or poor compatibility with pH and heat history. The follow-up record should preserve sample point, method condition, lot identity, storage age and corrective action so another reviewer can repeat the conclusion.
FAQ
Why is phosphoric acid used in cola?
It gives sharp acidity, lowers pH and fits the flavour balance of cola-type beverages.
How did EFSA assess phosphates?
EFSA set a group ADI of 40 mg/kg body weight per day expressed as phosphorus for phosphates from all sources.
Sources
- PubChem: Phosphoric AcidOpen chemical database used for phosphoric acid identity and acidulant context.
- Re-evaluation of phosphoric acid and phosphates (E338-E341, E343, E450-E452)EFSA opinion used for phosphate ADI, phosphorus exposure and group safety context.
- Phosphate Additives in Food - a Health RiskOpen-access review used for inorganic phosphate absorption and processed-food exposure context.
- Industrial Use of Phosphate Food Additives: A Mechanism Linking Ultra-Processed Food Intake to Cardiorenal Disease Risk?Open-access review used for phosphate additive functions and hidden phosphorus concerns.
- Strategies for replacing phosphates in meat processingOpen-access review used for water-holding, protein solubilisation and phosphate replacement in meat systems.
- EFSA: Food additivesUsed for food-additive re-evaluation and EU safety-assessment context.
- Codex General Standard for Food Additives Online DatabaseUsed for international additive categories and functional classes.
- FDA Food Additive Status ListUsed for US additive naming, status and cross-checking.