What is E622?

Complete guide to understanding E622 (Monopotassium Glutamate) in your food

The Quick Answer

E622 is monopotassium glutamate (MPG), the potassium salt of glutamic acid, used as a flavor enhancer to provide the “umami” (savory) taste—functioning as a non-sodium alternative to MSG (E621) that delivers identical flavor-enhancing function while reducing sodium intake.

It’s a potassium salt version of glutamate, providing the characteristic savory “fifth taste” (umami) by enhancing natural food flavors, used in baked goods, soups, sauces, and processed foods where flavor enhancement is desired without excess sodium.

Most people consuming processed foods, soups, broths, baked goods, and sauces regularly encounter E622, though it remains largely invisible—functioning as a flavor enhancer with official regulatory approval but facing ongoing scientific debate about potential neurotoxic effects at high cumulative exposure levels, particularly in sensitive populations (infants, children, pregnant women).

The Critical Context

E622 monopotassium glutamate is part of the glutamate family (E620-E625) where the 2017 EFSA re-evaluation found a critical safety concern: cumulative glutamate exposure from food additives, natural food sources, and nutrients EXCEEDS the safe level (ADI) for infants, toddlers, and children, with documented neurotoxic potential and MSG symptom complex at high doses. Unlike most other additives discussed, E622’s regulatory status remains approved despite scientific evidence that typical consumption patterns exceed safe exposure levels in vulnerable populations.

What Exactly Is It?

E622 is monopotassium glutamate (monopotassium L-glutamate), the potassium salt of L-glutamic acid with molecular formula KC₅H₈NO₄ and molecular weight of 205.27 g/mol.

Glutamic acid is one of the 20 standard amino acids—the building blocks of protein. When provided as a salt (monosodium glutamate/MSG or monopotassium glutamate/MPG), it functions as a taste enhancer, amplifying the perception of umami (savory) taste. E622 is specifically the POTASSIUM salt version, providing the flavor-enhancing function of glutamate while substituting potassium for sodium—useful for reducing sodium content in foods.

Physically, E622 appears as a white crystalline powder. It is soluble in water and has a characteristic strong savory/umami taste. The compound is heat-stable and maintains flavor-enhancing activity through food processing and storage.

Chemically, E622 functions through a mechanism distinct from other taste categories (sweet, sour, salty, bitter): it activates umami taste receptors on the tongue, enhancing perception of natural savory flavors in foods. Upon ingestion, the glutamate is absorbed in the intestine and metabolized like dietary protein. The potassium cation is absorbed and excreted like dietary potassium.

Where You’ll Find It

E622 appears in a wide range of processed foods where flavor enhancement is desired:

• Soups and broths (primary application)
• Baked goods and bakery products
• Sauces and gravies
• Condiments (soy sauce, fish sauce)
• Snack foods and chips
• Processed meats and meat products
• Ready-to-eat meals
• Seasonings and spice blends
• Cheese products
• Vegetable-based foods
• Asian cuisine products
• Instant noodles and instant foods
• Bouillon cubes and stock cubes
• Canned vegetables
• Savory spreads
• Beverages (less common than in savory foods)

E622 is particularly prevalent in soups, broths, and baked goods where cumulative glutamate exposure is highest.

Why Do Food Companies Use It?

E622 performs one critical commercial function with specific advantages:

Flavor enhancement with sodium reduction: E622 monopotassium glutamate enhances natural savory flavors in foods, allowing manufacturers to reduce salt content while maintaining or improving taste perception. At concentrations of 0.1-1%, glutamates amplify umami perception, making foods taste more flavorful without additional salt. This is particularly valuable in health-conscious formulations claiming sodium reduction.

Why potassium salt instead of sodium: E622 (potassium salt) is selected over E621 (sodium salt/MSG) specifically when sodium reduction is important—allowing manufacturers to market “low-sodium” while maintaining flavor enhancement. The potassium substitution provides functional advantage for specific target markets (consumers monitoring sodium intake, cardiovascular-health-conscious consumers).

Is It Safe?

E622’s safety status is officially approved but faces critical scientific concern: 2017 EFSA re-evaluation found that cumulative glutamate exposure in infants, toddlers, and children EXCEEDS safe levels, with documented neurotoxic potential and MSG symptom complex at high doses—a situation where regulatory approval persists despite evidence of unsafe exposure patterns in vulnerable populations.

Regulatory Status—Approved Despite Exposure Concerns:

• FDA (USA): Generally Recognized As Safe (GRAS); no ADI limit explicitly set
• EFSA (Europe): Approved; ADI 32 mg/kg bw (set in 2017 re-evaluation)
• JECFA (WHO/FAO): Approved; ADI 32 mg MSG/kg bw per day
• CRITICAL ISSUE: 2017 EFSA found exposure EXCEEDS ADI for infants, toddlers, children, and adolescents at high consumption levels

Documented findings and concerns:

• No genotoxicity: EFSA concluded no genotoxic concern
• No carcinogenicity: No evidence of carcinogenic potential
• Absorption mechanism: Glutamate is presystemically metabolized in the gut wall; limited evidence that high-dose MSG increases brain glutamate concentration
• Increased organ weights: Animal studies documented increased kidney and spleen weight, but EFSA deemed this non-adverse (no histopathological findings)
• Neurotoxic potential: Glutamate as excitotoxin; underdeveloped blood-brain barrier in children raises vulnerability
• MSG symptom complex: Well-documented condition: burning sensations, facial pressure, chest pain, headache at doses >42.9 mg/kg bw
• Exposure exceeds safe levels: 2017 EFSA explicitly found typical exposure in children exceeds safe reference doses
• Vulnerability of infants/children: Blood-brain barrier underdeveloped; cumulative exposure higher relative to body weight; soups and baked goods major sources
• Hidden sources: Glutamate present not only as E622 additive but also naturally in foods (tomatoes, cheese, mushrooms) and as nutrient additions

The 2017 EFSA Re-Evaluation—Critical Safety Assessment

The 2017 European Food Safety Authority re-evaluation of glutamates (E620-E625) reached a critical conclusion: cumulative glutamate exposure from all sources EXCEEDS safe levels in vulnerable populations, particularly infants and children.

EFSA explicitly stated: “The Panel noted that the exposure to glutamic acid and glutamates (E 620–625) exceeded not only the proposed ADI, but also doses associated with adverse effects” in infants, toddlers, and children at the 95th percentile exposure level. The Panel identified that soups, broths, and fine bakery wares for children were the primary contributors to excessive exposure. Despite this finding, E622 regulatory approval was maintained.

Production Method

E622 monopotassium glutamate is produced through fermentation:

1. Corynebacterium glutamicum bacteria are cultured in fermentation tanks containing molasses or glucose as substrate
2. Under controlled anaerobic conditions, the bacteria produce glutamic acid as a secondary metabolite
3. The fermentation broth is harvested containing L-glutamic acid
4. Glutamic acid is recovered through precipitation and purification
5. The purified glutamic acid is neutralized with potassium hydroxide or potassium carbonate, forming potassium salt (E622)
6. The product is crystallized, dried, and standardized for purity
7. Note: Some production uses genetically modified Corynebacterium glutamicum EA-12 strain (approved in 2015 as safe)

Production is fermentation-based with partially natural origin, though the bacterial strain and potassium salt formation are industrial processes.

Natural vs Synthetic Version

E622 is fermentation-derived with a partially natural origin—produced through bacterial fermentation but with chemical salt formation making it technically synthetic.

While glutamic acid is naturally produced by bacteria through fermentation (a natural process), E622 is created by isolating the bacterial product and forming a potassium salt—making it technically a synthesized/extracted compound rather than naturally-sourced. Some sources classify it as “nature-derived” (fermentation-based) while others classify as “synthetic” (salt formation). The distinction is that the glutamic acid originates from biological fermentation, but the final product E622 requires synthetic salt formation.

Glutamate Family Overview

E622 is one of six glutamate flavor enhancers (E620-E625) sharing identical safety concerns:

• E620 (Glutamic acid): Free acid form; naturally present in foods and proteins
• E621 (Monosodium glutamate/MSG): Sodium salt; most commonly used; identical neurotoxic concerns; adds sodium
• E622 (Monopotassium glutamate): Potassium salt; non-sodium alternative; identical neurotoxic concerns; same exposure risks
• E623 (Calcium diglutamate): Calcium salt; less commonly used
• E624 (Monoammonium glutamate): Ammonia salt; rare
• E625 (Magnesium diglutamate): Magnesium salt; rare

All share identical safety concerns documented in 2017 EFSA re-evaluation regarding cumulative exposure exceeding safe levels.

Comparison with MSG (E621)

E622 monopotassium glutamate is functionally identical to E621 monosodium glutamate (MSG) except for the cation (potassium vs sodium):

• Identical flavor-enhancing mechanism: both activate umami taste receptors
• Identical glutamate content and neurotoxic potential
• Identical absorption and metabolism (glutamate portion)
• E622 advantage: potassium instead of sodium—useful for sodium-reduction formulations
• E622 disadvantage: higher cost than E621; less commonly used
• Both subject to identical exposure concerns documented in 2017 EFSA re-evaluation
• Both exceed safe levels in children at typical high consumption

Environmental and Sustainability

E622 production through fermentation is relatively sustainable—uses renewable carbohydrate substrates (molasses, glucose), generates minimal waste, and does not rely on petroleum. The fermentation-based production is more sustainable than purely synthetic chemical synthesis. However, agricultural inputs for substrate production carry environmental costs.

Consumer Actions to Minimize E622 Exposure

For consumers concerned about glutamate exposure, particularly protecting children:

• Limit soups and broths (primary source of excessive glutamate)
• Reduce fine baked goods and bakery products for children
• Check labels for “glutamate,” “flavor enhancer,” “E622,” “E621” (MSG)
• Avoid products combining glutamate additives with natural glutamate sources (tomato-based sauces + E622)
• Prepare home-made foods without added glutamate to reduce cumulative exposure
• Pay special attention to products marketed for children; these commonly exceed safe exposure levels according to 2017 EFSA
• Understand that complete avoidance is impractical (glutamate naturally present in many foods) but reducing added forms significantly lowers exposure
• Be aware that “low-sodium” products using E622 may be reducing salt health concern while raising glutamate exposure concern

The Bottom Line

E622 (monopotassium glutamate) is a fermentation-derived potassium salt of glutamic acid used as a flavor enhancer providing the umami (savory) taste, officially approved by FDA, EFSA, and JECFA, but with a critical scientific finding from 2017 EFSA re-evaluation: cumulative glutamate exposure from food additives (E622, E621), natural food sources, and nutrient additions EXCEEDS the safe level (ADI of 32 mg/kg bw per day) in infants, toddlers, children, and adolescents, with documented neurotoxic potential and MSG symptom complex at high doses, representing a unique situation where regulatory approval persists despite scientific evidence of unsafe exposure patterns in vulnerable populations.

E622 is the potassium salt form of glutamic acid, functioning as a flavor enhancer that amplifies perception of umami (savory) taste. It is produced through bacterial fermentation of molasses, making it partially natural (fermentation-derived) while the potassium salt form is synthetic. At 0.1-1% concentrations, E622 enhances natural food flavors, allowing manufacturers to reduce sodium while maintaining taste appeal.

The critical distinction of E622 is that it represents a flavor enhancer facing documented unsafe exposure levels in vulnerable populations despite continued regulatory approval. The 2017 EFSA re-evaluation found that cumulative glutamate exposure from food additives, natural sources, and nutrient additions EXCEEDS safe levels at the 95th percentile in infants, toddlers, and children. Soups, broths, and fine baked goods for children were identified as primary sources of excessive exposure.

The safety concern is not acute toxicity (which is low) but rather cumulative neurotoxic potential: glutamate is a neurotransmitter, and the underdeveloped blood-brain barrier in children creates vulnerability to excitotoxicity (excessive neuronal stimulation). MSG symptom complex and other adverse effects are documented at high doses (>42.9 mg/kg bw for MSG symptom complex)—doses exceeded by typical consumption patterns in vulnerable populations.

E622 differs from all other additives discussed in this series by being officially approved despite scientific evidence that regulatory exposure recommendations are exceeded in vulnerable populations. This represents a unique regulatory situation where approval persists despite documented unsafe exposure patterns.

For consumers, E622 represents a flavor enhancer with two-part risk: the documented neurotoxic potential of glutamate itself, and the practical reality that cumulative exposure from multiple sources (soups, baked goods, sauces, natural foods) far exceeds safe levels in children according to 2017 EFSA assessment.