E632: properties, uses, pros, cons, safety

E632, best known as Dipotassium inosinate, is the dipotassium salt of inosinic acid (inosinate), also known as 5′-inosine monophosphate (IMP). It is a food additive in the ribonucleotide class used primarily as a flavour enhancer (umami), often in synergy with glutamates and guanylates.

Synonyms: dipotassium 5′-inosinate; potassium inosinate; dipotassium inosine-5′-monophosphate; INS 632 (Codex).

INCI / functions: not applicable (food additive; not a standard cosmetic ingredient).

Definition

Dipotassium inosinate is a phosphorylated ribonucleotide derived from inosine (a nucleoside), naturally present as a biochemical “building block” in living organisms and produced industrially for food use in purified and standardized form. Functionally, it does not create an intense standalone taste like a flavouring; rather, it boosts and “rounds out” savouriness perception, especially in salty and protein-forward matrices, often reducing the need for high loads of other enhancers or salt in certain formulation strategies.

In the EU it is identified as E632 and belongs to the ribonucleotide group (E626–E635), with use conditions defined by food category (in many cases within a group approach and under a “quantum satis” logic at the group level).

Main uses

Food.
Used as a flavour enhancer in savoury products (e.g., snacks, seasonings, meat/fish preparations, sauces and ready meals, depending on category and applicable conditions of use). The synergistic effect with glutamates (e.g., E621) and with guanylates (e.g., E627/E628) is well known, increasing umami perception at comparable total enhancer dosage.

Calories (energy value)

Practically, dipotassium inosinate is used at low doses (typical of flavour enhancers), so its energy contribution to the finished product is normally negligible. A single “energy value” for the additive as a raw material is not an operationally central parameter in formulation; for labeling, what matters is the real impact on the finished product (usually marginal at use levels).

Identification data and specifications

Physico-chemical properties (indicative)

Functional role and practical mechanism of action

In food formulation, E632 acts as a savouriness “multiplier”: it increases umami perception and taste persistence, especially in salty products and matrices rich in protein-derived notes or “broth/meaty” flavour profiles. The effect is often more pronounced when glutamate is present or when ribonucleotide blends are used (a common approach in seasonings). Practically, this supports sensory optimization and, in some projects, can help reduce salt load or other enhancers—always within specifications and product positioning constraints.

Formulation compatibility

It is generally compatible with the main savoury food matrices. Typical watchpoints include: stability under intense thermal processing, pH management (avoiding unnecessary extremes), and interactions with flavours/extracts that can amplify or unbalance the umami profile. In dry blends, moisture control and dispersion quality influence uniformity and sensory repeatability.

Use guidelines (indicative)

Dose and permitted categories depend on the applicable legislation and category specifications. In product development, it is advisable to build a dose-response sensory optimization curve and verify behaviour over shelf-life, especially for heat-treated products or those with non-neutral pH. In the EU, for foods intended for infants and young children, the general principle is that additives are not permitted unless specifically provided for; therefore, use requires particularly strict control of category and applicable conditions.

Quality, grades, and specifications

Typical quality specifications include identity (chromatographic methods), assay/purity, moisture, inorganic impurities and limits on trace metals. International monographs (e.g., JECFA) are commonly used as a technical reference for specifications and acceptance criteria, alongside applicable EU specifications.

Implementation of GMP (good manufacturing practice; benefit: reduces variability and contamination) and, for food operators, HACCP (hazard analysis and critical control points; benefit: strengthens preventive control of critical process points) supports repeatability and compliance throughout the supply chain.

Safety, regulatory, and environment

From a toxicological standpoint, international evaluations have applied a “group ADI not specified” approach to inosinic acid and certain salts (including the dipotassium salt): practically, under technologically justified use and good practice, no specific concern emerges that would require a numeric ADI.

From an individual nutrition perspective, it is worth noting that this is a compound from the nucleotide/purine family: for individuals with medical indications related to purine metabolism (e.g., hyperuricemia/gout), practical relevance depends primarily on the overall diet profile and the finished product, rather than on the single additive per se; dietary choices should be managed with clinical criteria.

Regulatorily in the EU, use is constrained by the permitted categories and conditions defined under the food-additives framework; moreover, for foods intended for infants and young children, additives are generally not permitted unless explicitly listed as an exception in the annexes.

Formulation troubleshooting

Overly strong umami profile or unbalanced taste note.
Typical cause: excessive dose or unbalanced synergy with glutamates/flavours. Action: reduce dose, rebalance the enhancer blend, and retune flavours.

Loss of effectiveness after severe thermal processing.
Typical cause: prolonged thermal stress and non-optimal pH conditions. Action: optimize the process profile and verify pH range, including evaluation of the most appropriate point of addition in the recipe.

Conclusion

Dipotassium inosinate (E632) is a ribonucleotide flavour enhancer used to boost umami and improve roundness and taste persistence, often in synergy with other enhancers. In formulation, the main technical drivers are correct dose management (to avoid imbalance), robustness under process conditions, and compliance with category-specific EU conditions of use, with particular attention to foods intended for infants and young children.

Mini-glossary

Umami: a savoury taste associated with glutamate and nucleotides, typical of broths and protein-forward preparations.
Ribonucleotides: nucleotides derived from ribose and nitrogenous bases; in food some act as flavour enhancers.
ADI: acceptable daily intake. “Not specified” indicates no need for a numerical value under correct conditions of use.
GMP: good manufacturing practice; benefit: improves quality control and reduces contamination/variability.
HACCP: hazard analysis and critical control points; benefit: strengthens prevention and control of critical process points.

• Molecular Formula  C₁₀H₁₁K₂N₄O₈P
• Molecular Weight      424.39 g/mol
• CAS  20262-26-4
• UNII    3BYM6LW3RF
• EC Number 243-652-3