What is E300?
Complete guide to understanding E300 (Ascorbic Acid/Vitamin C) in your food
The Quick Answer
E300 is vitamin C (ascorbic acid)—an essential nutrient that functions as an antioxidant and preservative to prevent fats and oils from becoming rancid.
It’s used in juices, canned foods, baked goods, meat products, and virtually every food category where oxidation protection is needed.
It is one of the safest food additives available, with no documented adverse health effects at food use levels. EFSA concluded there is no need for a numerical ADI limit because ascorbic acid is so fundamentally safe—reflecting the highest regulatory confidence in any food additive.
📌 Quick Facts
- Category: Natural antioxidant, preservative, vitamin (when added as fortification)
- Chemical Name: Ascorbic acid or L-ascorbic acid
- Chemical Formula: C₆H₈O₆
- Source: Occurs naturally in fruits/vegetables; industrially synthesized from D-glucose via bacterial fermentation
- Found in: Juices, canned fruits/vegetables, baked goods, meats, dairy, oils, beverages, processed foods
- Safety Status: FDA GRAS; EFSA approved; NO numerical ADI required (safest rating); JECFA approved
- Health Impact: Essential nutrient humans cannot synthesize; critical for collagen, iron absorption, immune function
- Safety Grading: GREEN – SAFE; one of the safest food additives available globally
What Exactly Is It?
E300 is ascorbic acid, the chemical name for vitamin C—an essential nutrient that humans require but cannot produce themselves.
Its chemical formula is C₆H₈O₆.
Ascorbic acid occurs naturally in citrus fruits (oranges, lemons, limes), berries (blackcurrants, redcurrants), peppers, tomatoes, potatoes, and many other fruits and vegetables.
Food-grade E300 is industrially synthesized from D-glucose through bacterial fermentation followed by chemical conversion. The synthesis process involves converting glucose to sorbitol, fermenting sorbitol to sorbose using Gluconobacter bacteria, and then oxidizing and processing the sorbose to produce pure ascorbic acid. The final product is a white or pale-yellow crystalline powder.
Mechanism: Ascorbic acid functions as a reducing agent (antioxidant) by donating electrons to free radicals, neutralizing them before they can damage fats, proteins, or other food components. It also chelates (binds) metal ions like copper and iron, preventing them from catalyzing oxidation reactions. Additionally, in meat curing, vitamin C inhibits formation of carcinogenic nitrosamines.
E300 is chemically identical whether derived from natural fruit extract or industrial synthesis—the human body cannot distinguish between them.
Where You’ll Find It
E300 appears in virtually every food category:
• Fruit juices and nectars (citrus, pineapple, passion fruit)
• Canned fruits and vegetables
• Baked goods (bread, pastries, cakes)
• Processed meats (sausages, deli meats, bacon)
• Oils and fats (animal and vegetable)
• Dairy products (milk, yogurt, cheese)
• Beer and wine
• Soft drinks and beverages
• Instant foods and powders
• Ice cream and frozen desserts
• Confectionery and sweets
• Infant and children’s foods (permitted)
• Nutritional supplements
• Cosmetics and personal care products
• Pharmaceuticals
E300 is one of the most universally used food additives due to its dual function as preservative and nutritional supplement.
Why Do Food Companies Use It?
E300 serves multiple critical functions:
Prevents oxidative rancidity: Fats and oils naturally oxidize when exposed to air, producing rancid off-flavors and potentially harmful oxidation byproducts. E300 prevents this degradation, extending shelf-life by months or years.
Preserves color and flavor: Prevents browning, color loss, and off-flavor development in fruits, vegetables, and processed foods.
Prevents nitrosamine formation: In processed meats, E300 inhibits formation of carcinogenic nitrosamines (N-nitroso compounds) from curing salts—a critical safety function.
Chelates harmful metals: Binds copper and iron, preventing their role in catalyzing oxidation and potential toxicity.
Nutritional fortification: E300 simultaneously provides vitamin C nutrition to consumers—serving both preservation and health benefit.
Natural image: “Vitamin C” sounds natural and healthy compared to synthetic preservatives.
Cost-effective: Inexpensive raw material (glucose) and simple manufacturing make E300 economical.
Is It Safe?
Yes—E300 is one of the safest food additives available. EFSA concluded there is no need for a numerical ADI limit because ascorbic acid is fundamentally safe, and no adverse health effects are documented at food use levels.
The FDA classifies ascorbic acid as GRAS (Generally Recognized as Safe).
The EFSA’s 2015 comprehensive re-evaluation concluded: “There is no safety concern for the use of ascorbic acid (E 300)…as food additives at the reported uses and use levels and there is no need for a numerical acceptable daily intake (ADI) for ascorbic acid and its salts.”
The JECFA (WHO Expert Committee) also confirmed safety with no numerical ADI limit.
• No genotoxicity (DNA damage) at any tested dose
• No carcinogenicity; long-term studies showed no chronic toxicity or cancer risk
• No reproductive or developmental toxicity
• No organ toxicity at food-use levels
• Very low acute toxicity
• No documented adverse effects in human populations at food-use levels
• Essential nutrient humans require for survival
• Regulatory consensus: NO numerical ADI needed (reserved for exceptionally safe substances)This is the highest regulatory safety confidence possible for a food additive—reflecting that ascorbic acid is not just “safe” but fundamentally beneficial to human health.
What Are The Health Concerns?
E300 has no documented health concerns at food-use levels. However, some considerations exist at extremely high doses (beyond food consumption):
No health concerns at food-use levels: EFSA, FDA, and JECFA all concluded no adverse effects at approved food use levels. Extensive human consumption history globally supports safety.
Minor gastrointestinal effects (extremely high doses only): At very high supplemental doses (2,000+ mg/day from supplements), some people report diarrhea, nausea, stomach cramps, or flushing. Food-use levels in processed foods pose no such risk.
Kidney stone risk (supplement use, not food): Extremely high supplemental vitamin C intake (3,000+ mg/day) may increase kidney stone risk in susceptible individuals. Food consumption poses no such risk.
Iron overload interaction (theoretical): Vitamin C increases iron absorption, which could be problematic in individuals with hemochromatosis (iron overload disorder). However, this applies to supplement megadoses, not food-use levels.
Rapid oxidation in aqueous solutions: E300 itself oxidizes rapidly in water, light, or when exposed to air—this is why it’s effective as an antioxidant. However, this is a functional property enabling its preservative action, not a safety concern.
No concerns for any population group: E300 is safe for children, pregnant women, elderly, immunocompromised—all populations.
Natural vs Synthetic Version
E300 is chemically identical whether naturally derived or synthetically produced.
All E300 has the same chemical formula (C₆H₈O₆) and biological activity regardless of source. The human body cannot distinguish between ascorbic acid extracted from oranges and ascorbic acid synthesized from glucose fermentation.
Most food-grade E300 is industrially synthesized from glucose via bacterial fermentation, which is economical and provides consistent purity. However, natural extraction from plant concentrates is also used and produces identical chemical compounds.
Natural Alternatives
E300 IS already a natural ingredient.
Other antioxidant preservatives include:
• Vitamin E/Tocopherols (E306) – natural fat-soluble antioxidant
• Rosemary extract – natural antioxidant (carnosic acid)
• Green tea extract – natural antioxidant (catechins)
• Oregano extract – natural antioxidant
• Citric acid (E330) – chelates metals; synergistic with antioxidants
• Calcium disodium EDTA (E385) – chelates metals (though controversial with emerging health concerns)
• Fresh foods with shorter shelf-life – accept reduced shelf-life, higher cost
The Bottom Line
E300 (Ascorbic Acid/Vitamin C) is an essential nutrient and one of the safest food additives available, with no documented adverse health effects at approved food-use levels. EFSA’s determination that no numerical ADI is needed reflects the highest regulatory confidence in any food additive—indicating E300 is fundamentally safe and beneficial.
Regulatory Consensus: FDA GRAS, EFSA approved (no ADI needed), JECFA approved—unanimous agreement on safety from all major food authorities.
Essential Nutrient: E300 is vitamin C, an essential nutrient humans cannot synthesize and must obtain from diet. Unlike most food additives (which are non-essential), ascorbic acid provides actual nutritional benefit.
No Adverse Effects Documented: Extensive long-term human consumption history globally, combined with comprehensive animal toxicology studies, shows no genotoxicity, carcinogenicity, reproductive toxicity, or organ damage at food-use levels.
Dual Benefit: E300 simultaneously provides food preservation (extending shelf-life) AND nutritional fortification (providing essential vitamin C). Few food additives combine these benefits.
Nitrosamine Prevention Critical Function: In processed meats, E300 inhibits formation of carcinogenic nitrosamines from curing salts—a protective health function rather than a safety risk.
Healthy Population Effects: Consumption of E300 in foods may provide some health benefits due to vitamin C content—collagen synthesis, iron absorption, immune function, antioxidant protection.
Recommendation: E300 is one of the few food additives you should NOT try to avoid. It is safe, essential, and beneficial. In fact, ensuring adequate vitamin C intake (from both natural sources and E300-fortified foods) is health-promoting rather than concerning.