What is E579?

Complete guide to understanding E579 (Ferrous Gluconate) — an iron nutrient fortification additive used for black olives and iron supplementation, currently undergoing EFSA re-evaluation

✅ NUTRIENT FORTIFICATION ADDITIVE – UNDER RE-EVALUATION: E579 (Ferrous Gluconate) is a fundamentally different type of food additive compared to E551-E561: it’s an IRON NUTRIENT FORTIFICATION agent, not an anti-caking or colorant additive. E579 is used to darken black olives through oxidation and is also used as a pharmaceutical-grade iron supplement for treating iron-deficiency anemia. E579 is currently undergoing EFSA re-evaluation as part of the comprehensive gluconic acid additive re-evaluation program (E574-E579). EFSA’s call for data closes March 31, 2024, with a scientific deadline for assessment. E579 is approved as safe by FDA, EFSA, and JECFA with an established Tolerable Intake of 0.8 mg/kg body weight per day for iron (set 1987).

The Quick Answer

E579 (Ferrous Gluconate) is an iron nutrient additive used to darken black olives and fortify foods with iron — approved by FDA, EFSA, and JECFA, currently undergoing EFSA re-evaluation as part of comprehensive gluconic acid assessment program.

What makes E579 fundamentally different from all previous additives: E579 is the first additive in this research collection that is a NUTRIENT fortification agent, not a functional additive (anti-caking, coloring, etc.). Iron is essential to human nutrition; ferrous gluconate is a bioavailable form of iron used both in pharmaceutical supplements for anemia treatment AND in food additive form for olive processing and food fortification. This distinction is critical: while E551-E561 are additives that serve processing functions, E579 is a nutrient that also serves a processing function. E579 bridges the gap between pharmaceutical iron supplements and food additives. Most importantly, EFSA is currently re-evaluating E579 as part of a comprehensive assessment of gluconic acid-based additives (E574-E579), with scientific submissions due in March 2024, meaning E579’s status may be updated or changed based on new evidence.

E579 is unique: a nutrient fortification additive currently undergoing EFSA re-evaluation.

📌 Quick Facts

Chemical Name: Ferrous Gluconate; Iron(II) Gluconate; Iron(II) di-D-gluconate dihydrate
Type: Nutrient fortification additive; iron supplement; food additive
Chemical formula: C₁₂H₂₂FeO₁₄- 2H₂O; Molecular weight: 482
Appearance: Yellow-gray or light green fine powder or granules
Primary functions: Black olive darkening; iron fortification; anemia treatment
EU Status: Approved; currently undergoing EFSA re-evaluation (E574-E579 program)
FDA Status: Approved for food use; GRAS for iron fortification
JECFA Status: Approved; PMTDI 0.8 mg/kg body weight (iron)
Re-evaluation Timeline: EFSA call for data deadline March 31, 2024
Approved uses: Canned/bottled fruit and vegetables; olives (max 150 mg/l or kg)

What Exactly Is E579?

E579 is ferrous gluconate, an iron salt of gluconic acid used as a nutrient fortification additive for black olives and iron supplementation.

Chemical composition: Iron(II) salt of gluconic acid (C₁₂H₂₂FeO₁₄- 2H₂O)

Appearance: Yellow-gray or light green fine powder; insoluble in ethanol, soluble in water

Physical properties:

– Molecular weight: 482
– Specific optical rotation: +6.7° at 25°C
– Forms supersaturated aqueous solutions (stable temporarily)
– Poorly water-soluble but bioavailable when ingested
– Contains iron in +2 (ferrous) oxidation state

Key properties (functional):

– Highly bioavailable iron source (superior to some iron salts)
– Darkens olives through oxidation (distinctive black color)
– Provides iron nutrient for supplementation
– Effective for treating iron-deficiency anemia
– FDA-approved and pharmacopeial standard (USP, EP, BP)

🔬 Understanding E579’s Dual Nature: E579 is unique because it serves TWO roles simultaneously: (1) NUTRIENT — it provides bioavailable iron for human health, essential for oxygen transport; (2) FOOD ADDITIVE — it darkens olives and fortifies foods. Most other additives (E551-E561) serve only processing functions. E579 bridges pharmaceutical and food additive categories because iron is both a nutrient essential to health AND a functional ingredient for food processing.

Uses of E579: Nutrient Plus Processing Function

E579 serves both nutritional and functional purposes in food.

Use Type	Application	Function	Safety Status
Black olive darkening	Canned/bottled olives (EU approved use)	Oxidizes olives to black color	APPROVED (max 150 mg/l)
Iron fortification	Breads, cereals, beverages, supplements	Adds bioavailable iron nutrient	APPROVED (variable limits)
Medical/pharmaceutical	Iron supplement tablets, syrups, capsules	Treats iron-deficiency anemia	FDA/pharma approved
Color retention	Preserved vegetables	Maintains color in processed vegetables	APPROVED (food additive)

Primary EU-approved use: Black olives (canned or bottled) processed by oxidation; maximum 150 mg/l or mg/kg

Secondary approved uses: Iron fortification in various food categories with specific maximum levels

EFSA Re-evaluation: Currently Under Assessment

Most important current development: E579 is being re-evaluated as part of comprehensive gluconic acid additive program.

Official EFSA action: Call for data on re-evaluation of gluconic acid (E 574) and related food additives (E575-E579)

Timeline:

– Registration deadline for interested parties: September 15, 2023
– Submission deadline for scientific data: March 31, 2024
– EFSA assessment phase: Following submission deadline
– Status update: Pending completion of assessment

Why re-evaluation? Under EU Regulation 257/2010, all food additives permitted before January 20, 2009 must be re-evaluated by EFSA for safety. E579 was authorized before this date, triggering mandatory re-evaluation.

Assessment scope: Gluconic acid group (E574-E579) re-evaluated together, including:

– E574: Gluconic acid
– E575: Glucono delta-lactone
– E576: Sodium gluconate
– E577: Potassium gluconate
– E578: Calcium gluconate
– E579: Ferrous gluconate (iron nutrient)

⚠️ UNDER RE-EVALUATION: E579 is currently being re-evaluated by EFSA as part of the gluconic acid additive group assessment program. The scientific data submission deadline was March 31, 2024. Assessment phase is ongoing. E579’s approval status may be updated, modified, or potentially changed based on new evidence emerging during re-evaluation. This represents an opportunity for updated safety assessment based on current standards.

Safety Assessment and Tolerances

E579 safety has been established with specific tolerable intake limits for iron.

Regulatory approvals:

– FDA: Approved for food use; GRAS (Generally Recognized As Safe)
– EFSA: Approved; currently undergoing re-evaluation
– JECFA: Approved; established Tolerable Intake (see below)
– Australia/New Zealand: Approved (code 579)
– Pharmacopoeias: USP, EP, BP standards for pharmaceutical use

Iron Tolerable Intake (JECFA, 1987):

– PMTDI (Provisional Maximum Tolerable Daily Intake): 0.8 mg/kg body weight
– Basis: Provisional status reflects element approach rather than compound-specific
– Application: Applies to all iron-containing additives and supplements

Toxicity considerations: Iron toxicity recognized only with overdose — important distinction from chronic hazards of other additives

Overdose symptoms (Wikipedia reference): Iron toxicity in children occurs at 10-20 mg/kg elemental iron; serious toxicity at >60 mg/kg. However, normal food use and supplementation are far below these levels.

The Bottom Line

E579 is an iron nutrient fortification additive approved for black olive darkening and iron supplementation — currently undergoing EFSA re-evaluation with assessment ongoing.

Key facts about E579:

– Nutrient function: Provides bioavailable iron essential to human health
– Processing function: Darkens black olives through oxidation
– Medical use: Treats iron-deficiency anemia (pharmaceutical-grade)
– Regulatory approval: FDA approved; EFSA approved (re-evaluation ongoing)
– Safety established: JECFA tolerable intake 0.8 mg/kg body weight for iron
– Current status: Under re-evaluation; assessment pending completion
– Approved uses: Black olives (150 mg/l max); various fortified foods
– Bioavailability: Superior iron absorption compared to some iron sources

✅ BOTTOM LINE: E579 (Ferrous Gluconate) is an iron nutrient fortification additive used for black olive darkening and iron supplementation. Unlike anti-caking agents (E551-E561), E579 provides essential nutrition (iron) while also serving food processing functions. E579 is approved by FDA, EFSA, and JECFA with established safety tolerances. Most importantly, E579 is currently undergoing EFSA re-evaluation as part of the gluconic acid additive group assessment program (E574-E579), with scientific assessment ongoing as of 2024. E579’s approval status may be updated based on new evidence emerging during this re-evaluation process.

Final Thoughts: When Food Additives Are Also Nutrients

E579 represents an important category expansion: food additives that are simultaneously essential nutrients.

E579’s unique position in food safety: Unlike E551-E561, which are processing aids that help manufacture food without being essential to nutrition, E579 provides iron — an essential nutrient. This creates a fundamentally different regulatory framework. E579 isn’t about preventing caking or maintaining color for processing convenience; it’s about ensuring iron availability for human health.

Why this matters: The safety threshold for E579 is not “minimal but safe exposure” but rather “adequate for nutritional benefit.” Iron deficiency is a health problem; E579 addresses it. The tolerable intake is designed to prevent iron overload, not to minimize exposure.

Current re-evaluation significance: EFSA’s ongoing assessment of E579 within the gluconic acid additive group may update iron fortification standards based on current evidence. This represents an opportunity for safety science to evolve based on new data.

Consumer implications:

– E579 in black olives: safe at permitted levels (150 mg/l max)
– E579 as iron supplement: bioavailable source for nutritional benefit
– Re-evaluation ongoing: approval status may be updated in 2024/2025
– Iron tolerance: essential element; toxicity only with overdose
– Pharmaceutical use: effective treatment for anemia

The bigger picture: E579 demonstrates that food additive safety isn’t monolithic. Some additives (aluminum silicates) are concerning at current exposure. Others (E579 iron nutrient) are beneficial at appropriate levels. The distinction lies in whether the substance provides health benefit or just serves manufacturing convenience. E579 bridges both worlds: it serves manufacturing (olive darkening) while providing nutrition (iron supplementation).

What is E579? – Complete guide to understanding Ferrous Gluconate