Purple Corn Extract
Purple corn extract is the anthocyanin bearing preparation obtained from the pericarp and cob of pigmented varieties of Zea mays, principally the Peruvian landrace maiz morado. Its colour comes from a set of anthocyanins dominated by cyanidin-3-glucoside, together with pelargonidin-3-glucoside, peonidin-3-glucoside and their malonylated derivatives, accompanied by phenolic acids and condensed tannins.
In food the extract functions as a colour, giving red to purple shades in acid systems, and as a polyphenol active in supplements. The pigment is unusually rich in the acylated and malonylated forms, which are more resistant to fading than the simple glycosides carried by many other anthocyanin sources, and that stability is the reason for its commercial position among natural reds.
Commercial material is a dark purple to reddish black powder or a viscous liquid concentrate, freely soluble in water and in aqueous ethanol. The colour is strongly pH dependent, showing a clear red below pH 3, shifting through purple around pH 4 to 5 and toward blue and grey above pH 6, and fading in the presence of ascorbic acid, sulphite, high heat and light. Colour strength is quoted as colour value rather than as anthocyanin percentage alone.
We source bulk Purple Corn Extract from top China manufacturers for our partners. The manufacturer is in Shaanxi. A smaller requirement can ship in a combined container with other ingredients.
Please send the grade you need, the volume and your destination port, and we will come back with a solution and a price.
or call +86-21-6858 0751
- Function
- Plant extract
Specifications
| Item | Specification |
|---|---|
| Appearance | Dark purple to reddish black fine powder |
| Odour and Taste | Slight characteristic cereal, faintly astringent |
| Total Anthocyanins (pH differential) | ≥ 5.0% |
| Colour Value E1% at 520 nm | ≥ 100 |
| Identification | Conforms by HPLC against cyanidin-3-glucoside reference |
| Loss on Drying | ≤ 5.0% |
| Total Ash | ≤ 5.0% |
| pH of 1% solution | 2.5 to 4.0 |
| Particle Size | 100% through 80 mesh |
| Residual Ethanol | ≤ 0.5% |
| Sulphur Dioxide | ≤ 10 mg/kg |
| Lead | ≤ 2.0 mg/kg |
| Arsenic | ≤ 1.0 mg/kg |
| Total Plate Count | ≤ 5,000 cfu/g |
| Yeast and Mould | ≤ 100 cfu/g |
| E. coli | Negative |
| Salmonella | Absent in 25 g |
Common Markets Grades
Colour grades are traded on colour value, measured as absorbance at around 520 nanometres in acid solution and expressed as E1% or as anthocyanin content by the pH differential method, commonly at 1 to 5 percent total anthocyanins for standard powders and up to 25 percent for concentrated grades. Liquid concentrates are quoted at a stated colour value and Brix. Maltodextrin carried spray dried powders are the standard article, and carrier free grades are made for label sensitive applications.
Supplement grades are standardised instead on total anthocyanins or total polyphenols by the Folin method, at 5 to 25 percent, and are sold on the antioxidant rather than the colour positioning. Cob derived and pericarp derived material differ in tannin content and are distinguished on the certificate. Organic certified purple corn is available, and grades are also split by whether the extract is presented as a colouring food, made by simple aqueous extraction, or as a selectively purified colour.
Applications
- Soft drinks and flavoured waters, where the acid pH holds a clean red to purple shade
- Confectionery including hard candy, gummies and coated products, as a replacement for synthetic red dyes
- Yoghurt, fruit preparations and dairy desserts, dosed against the acid of the fruit phase
- Ice cream and frozen desserts, where low temperature and darkness limit pigment fading
- Bakery fillings, icings and decorations formulated on the acid side
- Jams, jellies and fruit spreads, reinforcing the colour lost during cooking
- Dietary supplements in capsule and tablet form standardised on anthocyanin content
- Functional beverages and shots positioned on antioxidant polyphenol content
- Traditional Peruvian beverages and desserts made from the whole cob
- Cosmetic formulations, where the anthocyanin fraction is used for its colour and antioxidant activity
China Manufacturers of Purple Corn Extract
Top Purple Corn Extract manufacturers in China.
Company names and logos are the property of the manufacturers themselves. They are listed here because our own directory records them as producing this ingredient. A listing is not an endorsement by them, and we do not represent them or speak on their behalf.
Regulatory Status
In the United States colours obtained from fruit and vegetable juices are listed as colour additives exempt from certification, and purple corn colour is sold within that framework, so its use for colouring food depends on falling within the applicable juice colour listing and on meeting the conditions stated there. Purple corn extracts sold on their polyphenol content are used as dietary ingredients under the Dietary Supplement Health and Education Act. A manufacturer intending to colour food in the United States confirms which listing covers its specific preparation rather than assuming a general permission for the plant.
In the European Union anthocyanins are an authorised food colour carrying the number E 163, regulated under Regulation 1333/2008 with purity criteria in Regulation 231/2012. Whether a given purple corn preparation is sold as E 163 or as a colouring foodstuff depends on how selectively the pigment has been extracted, since a simple aqueous extract that retains the other constituents of the plant is treated as a food rather than as an additive. The Joint FAO WHO Expert Committee has evaluated grape skin extract and anthocyanins as colouring matters, and Codex includes anthocyanins in its general standard for food additives.
Manufacturing Process
Dried purple corn cobs and pericarp are cleaned, shelled where whole cobs are used, and milled to a coarse particle size. The material is extracted in counter current flow with acidified water or with acidified aqueous ethanol at 40 to 60 degrees Celsius, and the acid is citric or a mineral acid that holds the anthocyanins in the stable flavylium form. Temperature is kept moderate because anthocyanins degrade quickly under prolonged heat.
The liquor is separated on a decanter centrifuge and clarified by plate and membrane filtration. For colour grades the clarified extract is loaded onto a macroporous adsorption resin that binds the anthocyanins while sugars, salts and organic acids pass to waste, and the pigment is then eluted with acidified ethanol. Solvent is recovered by vacuum distillation and recycled. The eluate is concentrated in a falling film vacuum evaporator at low temperature, standardised against an assayed batch to a target colour value, blended with maltodextrin where a carrier is specified, and spray dried at a controlled inlet temperature. Powder is sieved, assayed for colour value and anthocyanin content, and packed under a moisture and light barrier.
