The stability of natural colorings is not a uniform property: it changes radically from pigment to pigment, even before depending on the process or the matrix.
Curcumin, beta-carotene, chlorophylls, cochineal carmine, and beetroot – all present in the Bayo range of water-soluble natural colorings – respond completely differently to light, heat, pH, and oxygen.
Selecting the right pigment means knowing these profiles before starting matrix tests.
This guide analyzes the stability of natural colorings from the pigment’s perspective, not the process – which is already covered in the article on savory coloring stability.
Why stability varies between pigments
Water-soluble natural colorants are extracted from plant matrices with very different chemical compositions.
A carotenoid like beta-carotene is a polyene with conjugated double bonds, sensitive to oxidation.
A polyphenol such as anthocyanins is sensitive to pH in a much more pronounced way than any carotenoid.
Chlorophyll reacts to acidity by turning from green to olive brown.
This chemical diversity is the reason why degradation of colorings is not addressed with general rules, but with specific knowledge of the chosen pigment.
Stability profiles pigment by pigment
Curcumin – lemon yellow
Photosensitivity: high. This is the main critical point for curcumin. In transparent packaging or under intense lighting, color degradation is rapid and visible.
Thermal stability: good within typical pasteurization ranges. It withstands temperatures up to 80–90°C without significant loss of intensity.
pH sensitivity: present. In an alkaline environment, it shifts toward reddish tones. In an acidic environment, it maintains bright yellow better.
Recommended applications: beverages and syrups in opaque packaging, bakery glazes, preparations with short shelf life or controlled light exposure.
Beta-carotene – orange
Sensitivity to oxidation: high. The polyenic structure of beta-carotene makes it vulnerable to oxygen, especially in the presence of trace metals or in matrices with high water activity.
Thermal stability: good within standard ranges. It withstands pasteurization and processes at moderate temperatures.
Stability at pH: excellent. It maintains the orange tone in a wide range of acidity and alkalinity.
The preservation of colored foods based on beta-carotene requires careful packaging: airtight sealing, protective atmosphere, and limited oxygen exposure during processing.
Recommended applications: orange-flavored drinks, gelato bases, syrups, and preparations with airtight packaging.
Chlorophyll – green
Sensitivity to acidic pH: high. In an acidic environment, chlorophyll loses the magnesium ion and shifts toward olive or brown tones. It is the green pigment most sensitive to process conditions.
Thermal stability: limited in an acidic environment. In neutral or slightly alkaline pH, thermal resistance improves significantly.
The chromatic degradation of colorings based on chlorophyll is the main risk in acidic fruit sauces, preparations with citrus juices, and acidified yogurts.
Recommended applications: green tea beverages, herbal syrups, preparations with neutral or alkaline pH, and products with short shelf life.
Cochineal carmine – red
Thermal stability: high. Cochineal carmine – red
Stability at pH: good across a wide range. It maintains bright red in acidic conditions, with a slight shift toward purple in an alkaline environment.
Photosensitivity: moderate-low, higher than synthetics but among the best among naturals.
It is the most reliable choice for applications requiring robustness across multiple variables simultaneously: pasteurized products, jellies, desserts, long shelf life beverages.
Note: requires attention to label communication – some consumers are sensitive to the animal origin of carmine.
Beetroot – red/purplish
Sensitivity to heat: high. The betalains in beetroot are thermolabile. Prolonged treatments or temperatures above 70-75°C cause rapid loss of color intensity.
Photosensitivity: high. Among water-soluble natural pigments, beetroot is among the most light-sensitive.
pH stability: best in acidic environments (pH 3.5–5). It degrades in neutral or alkaline environments.
The shelf life of colored products based on beetroot is the most critical to manage. It should be reserved for products with low process temperatures, opaque packaging, and limited shelf life.
Recommended applications: yogurt, cold desserts, beverages not heat-treated or pasteurized at low temperatures.
Caramel – amber
Thermal stability: excellent. It is the most stable brown coloring available in water-soluble format.
Stability at pH: high over a very wide range, from acidic to neutral.
Photosensitivity: low.
For the shelf life of long-life products, caramel is often the default choice when an amber hue is acceptable in the finished product.
Colorant storage: warehouse and operational management
The storage of colorings before use directly impacts production yield.
A pigment stored in incorrect conditions arrives at the line already partially degraded, with direct consequences on chromatic yield and repeatability between batches.
Temperature
All water-soluble natural colorings benefit from storage in a cool place, away from heat sources.
Bayo micro-dosable powders maintain their characteristics under standard warehouse conditions but must be protected from thermal fluctuations that accelerate the degradation process.
Humidity
The hygroscopic powders can form clumps if exposed to humidity. This does not always compromise the pigment, but it makes precise dosing difficult and slows down dissolution.
Moisture absorption in the warehouse modifies solubility and dispersion, and in some cases, accelerates the chemical degradation of the pigment.
Airtight packaging, raised pallets, and periodic monitoring of relative humidity in the warehouse are essential operational practices.
Light
Curcumin, beta-carotene, and beetroot degrade even in open packages if exposed to artificial warehouse light.
Compliance with the hermetic sealing procedure after each use is not a formality: it is a technical measure with a direct impact on yield.
Stock rotation
The FIFO principle – first in, first out – is particularly relevant for natural colorings, where the ingredient’s shelf life is shorter compared to synthetics.
The ready-to-use water-soluble solutions require the same attention: they must be stored closed, protected from light, and used within the terms indicated in the technical data sheet.
Shelf life of colorants: from production to the consumer
The shelf life of colorants in the finished product is not calculated based on the shelf life of the ingredient.
These are two distinct values that follow different logics.
The ingredient’s shelf life refers to the storage of the pure coloring in the warehouse under the conditions indicated in the technical data sheet.
The shelf life of colorings in the finished product depends on the interaction of the pigment with the entire matrix: pH, fats, proteins, salt, heat treatment undergone, packaging, distribution conditions.
Determining the shelf life of finished products requires dedicated tests on representative samples, under the real storage conditions intended for the consumer.
Accelerated tests – temperature or light higher than normal – provide useful preliminary indications during the development phase.
They do not replace validation on real shelf life before commercial launch.
Instrumental color measurement with colorimeters allows for objective monitoring of degradation over time, beyond visual perception which is subject to environmental variables.
Production monitoring
In-line monitoring of natural colorant stability allows for the detection of chromatic variations before the batch is completed.
Portable spectrophotometers and vision systems can measure tone and intensity after mixing, signaling deviations from defined standards.
Recording pH, temperature, and process time for each batch creates a useful documentary base for analyzing deviations and for quality audits requested by customers.
The degradation of colorings between successive batches is often the signal of an uncontrolled process variable: change of raw material supplier, variation in water pH, process temperature out of specification.
A control plan that includes color as a batch acceptance parameter – not just a final check – reduces the risk of rework and waste.
How to choose the most stable coloring for the process
For high-temperature processes (baking, extrusion): beta-carotene, carmine, and caramel are the most resistant. Curcumin and beetroot are at high risk of fading.
Hue is the destination. Stability is the starting point.
For processes with severe thermal treatments: carmine and caramel are the most robust choices. Beta-carotene and curcumin hold up in moderate ranges. Chlorophyll and beetroot require post-process addition or low-temperature processes.
For products with acidic pH: beetroot and curcumin work well. The use of chlorophyll is critical.
For long shelf lives with transparent packaging: caramel and carmine are the most reliable. Curcumin and beetroot require protective packaging.
For organic productions: all natural colorings in the Bayo range are compatible with organic standards – synthetics are not.
The complete range is described on the food colorings page. For a comparison between water-soluble and fat-soluble natural colorings, the dedicated article covers selection criteria and applications by sector.
Bayo support for stability in production
Stability is not a static value: it is a result that is built through the correct combination of pigment, matrix, and process.
Certifications such as ISO 9001 and FSSC 22000 guarantee total traceability from raw material to finished product.
The Bayo technical team supports customers in selecting the correct pigment and in application tests on the real matrix.