Anthocyanins are source-dependent natural colours
E163 anthocyanins are natural colourants extracted from edible fruits and vegetables. They may come from grape skin, blackcurrant, elderberry, red cabbage, purple carrot or other permitted sources depending on region and specification. Anthocyanins are not a single compound. They are glycosylated flavylium pigments whose colour depends on anthocyanidin structure, sugar substitution, acylation, pH and matrix. A supplier specification must identify source and composition because grape skin extract and purple carrot extract do not behave identically.
EFSA concluded that the toxicological database was inadequate to establish a numerical ADI for E163, but that aqueous extracts from edible fruits and vegetables at exposures comparable with dietary intake were unlikely to be of safety concern. EFSA also recommended better specifications, especially for sources and extraction methods. For manufacturers, source and extraction route are part of safety and quality control.
pH controls colour
Anthocyanins are strongly pH-dependent. In acidic systems, they usually appear red or pink. As pH rises, they can shift toward purple, blue, colourless or degraded forms. This makes E163 excellent for acidic drinks, fruit preparations, yogurts and confectionery, but difficult in neutral bakery fillings, protein beverages or alkaline systems. A colour that looks bright red at pH 3 may become dull purple or unstable at pH 5.5.
Copigmentation, acylation and metal complexation can improve or shift colour. Purple carrot and red cabbage anthocyanins can be more stable in some applications because of acylation patterns. Grape skin extracts may behave differently and can bring tannins or flavour notes. Source choice should be based on target pH, heat process, flavour profile and label position.
Stability and process design
Heat, light, oxygen, enzymes, ascorbic acid, sulphites and metals can degrade anthocyanins or shift hue. Ascorbic acid can be helpful nutritionally but may accelerate anthocyanin degradation in some systems. Sulphites can bleach anthocyanins. Metal ions can create unwanted blue or grey complexes. Pasteurization, hot fill and long ambient storage should be tested with the real formula.
In beverages, test pH, vitamin C, package light and oxygen. In yogurt, test protein matrix, pH drift and light exposure. In confectionery, test cooking and acid addition. In dry powders, test reconstitution and moisture. Anthocyanins are powerful natural colours, but their pH chemistry must be designed rather than guessed.
Quality control
Incoming QC should include source, extraction method, anthocyanin content, carrier, residual solvents where relevant, microbiology, heavy metals, pH and colour strength. Finished-product release should include pH, colour coordinates, retained standard, heat history and shelf-life shade. If a supplier changes from one source to another, the product should be treated as reformulated because hue, flavour and stability can all change.
Failures should be read mechanistically. Red-to-purple drift points to pH or metal effects. Bleaching points to sulphites, ascorbate, oxygen or light. Sediment points to extract or matrix incompatibility. Dull colour after heat points to thermal degradation. E163 can be excellent, but only inside a pH and process window designed around anthocyanin chemistry.
Minimum effective dose
Minimum effective dose should be set at the target pH. If a product's pH drifts, extra anthocyanin may not solve hue change because the pigment chemistry has shifted. Stabilizing pH, choosing a more suitable source or using copigmentation can be better than increasing colour load.
Application examples
In acidic beverages, elderberry or grape anthocyanins may give red-purple shade, but vitamin C and light can bleach the colour. In yogurt, pH is favourable but proteins and light exposure influence appearance. In confectionery, cooking temperature and acid addition point can decide whether the red remains bright. In bakery fillings, pH may be too high for stable red, so purple carrot or red cabbage extracts may be chosen for more stable profiles. Application choice begins with pH.
Supplier change
Supplier change should compare source, anthocyanin content, acylation, carrier, residual solvents, flavour and colour at the product pH. Changing from grape skin to purple carrot is not a small sourcing change; it changes hue, stability, flavour and often label positioning. Finished-product trials should be repeated whenever source changes.
Operator control
Operators should control pH before final colour approval. Adding acid after colour can create local pH gradients and streaks. Sulphite-containing ingredients should be reviewed because sulphites can bleach anthocyanins. If ascorbic acid is present, storage testing should be stricter because vitamin C may accelerate colour loss.
Analytical release
Analytical release should pair pH with colour coordinates. Without pH, an anthocyanin result is hard to interpret. For beverages, include light and oxygen. For yogurts, include pH drift and cup light exposure. For confectionery, include cooking and acid addition. If colour is source-dependent, retain a source-specific standard rather than a generic red standard.
Label positioning
Label positioning should identify the source where required or commercially relevant. Grape skin, elderberry, purple carrot and red cabbage extracts may all be anthocyanin colours but carry different flavour, shade and consumer perception. The source can matter as much as the E number.
Storage release
Storage release should include the target pH at end of life. If pH moves during fermentation, fruit equilibration or acid diffusion, the approved shade may move with it. Anthocyanin colour cannot be released independently of pH.
Mechanism detail for Food Additive E163 Anthocyanins
Food Additive E163 Anthocyanins needs a narrower technical lens in Food Additives E Codes: pigment chemistry, pH, oxygen, light, metal ions, heat exposure and package transmission. This is where the article moves from naming the subject to explaining which variable should be controlled, why that variable moves and what would make the evidence unreliable.
The source list for Food Additive E163 Anthocyanins is strongest when each citation has a job. Re-evaluation of anthocyanins (E 163) as a food additive supports the scientific basis, Factors affecting the stability of anthocyanins and strategies for improving their stability: A review supports the processing or quality angle, and Anthocyanins: Natural Colorants with Health-Promoting Properties helps prevent the article from relying on a single method or a single product matrix.
Additive E163 Anthocyanins: additive-function specification
Food Additive E163 Anthocyanins should be handled through additive identity, purity, legal food category, maximum permitted level, carry-over, matrix compatibility, declaration and technological function. Those words are not filler; they define the evidence that proves whether the product, lot or process is still inside its intended control boundary.
For Food Additive E163 Anthocyanins, the decision boundary is dose approval, label check, market restriction, substitute selection or supplier requalification. The reviewer should trace that boundary to assay, purity statement, formulation dose calculation, finished-product check, label review and matrix performance test, then record why those data are sufficient for this exact product and title.
In Food Additive E163 Anthocyanins, the failure statement should name wrong additive class, excessive dose, weak function, regulatory mismatch, undeclared carry-over or poor compatibility with pH and heat history. The follow-up record should preserve sample point, method condition, lot identity, storage age and corrective action so another reviewer can repeat the conclusion.
FAQ
Why do anthocyanins change colour with pH?
Their flavylium structure shifts between different chemical forms as pH changes, changing hue from red to purple, blue or colourless.
Why does E163 need source specification?
Different fruit or vegetable sources have different anthocyanin profiles, acylation, flavour and stability.
Sources
- Re-evaluation of anthocyanins (E 163) as a food additiveEFSA opinion used for E163 source, specification and absence of numerical ADI.
- Factors affecting the stability of anthocyanins and strategies for improving their stability: A reviewOpen-access review used for pH, copigmentation, light, heat and metal effects on anthocyanins.
- Anthocyanins: Natural Colorants with Health-Promoting PropertiesOpen-access review used for anthocyanin structure, source and stability context.
- A critical review on the stability of natural food pigments and stabilization techniquesOpen-access review used for pH, heat, light, oxygen and metal effects on pigments.
- Impact of Conventional and Advanced Techniques on Stability of Natural Food ColourantsOpen-access review used for processing and packaging effects on natural colourants.
- Food Colour Additives: Chemical Properties, Applications in Food Products, and Health Side EffectsOpen-access review used for food colour chemistry and application context.
- Food additivesEFSA overview used for additive authorisation, specifications and safety-assessment context.
- Codex General Standard for Food Additives Online DatabaseCodex database used for food categories, functional classes and permitted additive uses.