What Is Ascorbic Acid (E300)?

What is ascorbic acid?

Ascorbic acid (E300, L-ascorbic acid, vitamin C) is a water-soluble vitamin used in the food industry for three different purposes: antioxidant, flour improver and nutrient fortifier. It is a white to slightly yellowish crystalline powder; about 33 g dissolves in 100 ml of water and the solution is acidic (pH 2.1–2.6). It is sensitive to heat, light, oxygen and metal ions (especially copper and iron).

Three different functions

As an antioxidant it binds oxygen and delays colour loss and flavour deterioration in juices, frozen fruit and vegetables and fatty products. As a flour improver it converts to dehydroascorbic acid in the presence of oxygen in the dough and accelerates disulphide bond formation between gluten proteins, increasing dough elasticity and gas retention and thereby bread volume. In cured meat products it speeds the reduction of nitrite to nitric oxide, making the cured colour fast and stable and reducing nitrosamine formation.

Applications and typical rates

20–100 ppm (on flour) as a flour improver in bread and bakery; 100–500 mg/l as antioxidant/fortifier in juices and beverages; 300–500 mg/kg in cured meat products (per regulation); 0.1–0.5% as a dipping solution for frozen fruit and vegetables; per the declared dose in dietary supplements. Overdosing to compensate for processing losses is common.

Grade selection: fine powder, granular, coated

Fine powder dissolves quickly and is preferred in liquid systems. The granular form reduces dust, flows well and prevents segregation in dry mixes. Coated grades protect ascorbic acid from moisture and oxygen and extend shelf life in dry mixes and tablets. Flour improver applications generally use fine powder or a premix diluted with a carrier.

Technical properties and quality criteria

Check purity (99–100.5%), moisture (≤ 0.4%), specific optical rotation (confirming the L form), pH, heavy metals, lead and arsenic, residual solvents, particle size, microbiological values and pharmacopoeia/food-grade conformity statement (USP, E.P. or FCC). A non-GMO statement is requested in many markets because production is fermentation-based.

Wholesale sourcing: price and minimum order

The wholesale price of ascorbic acid depends largely on Chinese production capacity and fermentation raw material costs; the market shows marked periodic swings. Origin, pharmacopoeia grade, particle form and order quantity all affect the price. The typical minimum order is 100–500 kg. PERDIST identifies the grade suited to your application, compares sources and provides a written quotation with documents.

Frequently asked questions