20. MONASCUS PURPUREUS
- INCI: Monascus extract
- Solubility: Hydrophilic
- Main chemical pigment(s): Rubropunctamine
- Colour: Red / purple
Monascus purpureus is a species of mould that is purplish-red in colour. During its growth, Monascus break down starch substrate into several metabolites, including pigments produced as secondary metabolites. The colour is currently available in purple and red. The main chemical pigment found in Monascus purpureus is Rubropunctamine, found to comprise between 57-87% of the total pigment produced.
21. NETTLE
- INCI: Urtica dioica leaf extract
- Solubility: Lipophilic
- Main chemical pigment(s): Chlorophyll
- Colour: Green
Nettle leaves contain caffeic acid, chlorogenic acid, high content of chlorophyll and other pigments. The leaves contain just under 5mg chlorophyll per gram of dry leaves, depending on whether the plant was grown in the sun or shade. Surprisingly, more chlorophyll and carotenoids are found in plants that have been grown in the shade. Chlorophyll is naturally oil soluble.
22. PAPRIKA
- INCI: Capsicum anuum extract
- Solubility: Lipophilic
- Main chemical pigment(s): Capsanthin, Capsorubin
- Colour: Red / purple
The pigments present in paprika are a mixture of carotenoids, in which capsanthin and capsorubin are the main compounds responsible for the red colour of the dye. It is rich in carotenoid pigments, including capsanthin, capsorubrin, carotene, luteine, zeaxanthin and cucurbitaxanthin. As well as being a pigment, it is also used in cosmetics in ointments, oils and emulsions for its stimulating effect and as a sports massage. Beware that capsanthin is warming on the skin (as anyone who has ever eaten a chilli will know!) and should be used in very low percentages (<0.1%) in cosmetics.
23. POMEGRANATE
- INCI: Punica granatum fruit extract
- Solubility: Hydrophilic
- Main chemical pigment(s): Punicalagin
- Colour: Red / purple
Anthocyanins are water-soluble pigments primarily responsible for the attractive red / purple colour of pomegranate juice, although the inedible fruit peels are the main source of colourants in pomegranate. Its chief constituents such as punicalagin, punicalin, gallagic and ellagic acids. It also contains alkaloids such as isopelletierine. Punica granatum dye and many other common natural dyes are reported as potent antimicrobial agents owing to the presence of a large amount of tannins.
24. RED CABBAGE
- INCI: Brassica oleracea leaf extract
- Solubility: Hydrophilic
- Main chemical pigment(s): Cyanidin-3-glucoside and Delphinidin-3-glucoside
- Colour: Pink / purple
Red cabbage, Brassica oleracea L. var. capitata, is well known for its pink / purple colour. Its water-soluble dye is composed mainly of natural pigment called anthocyanins used as a natural colourant. Eight anthocyanins are found in red cabbage, including cyanidin-3-glucoside and delphinidin-3-glucoside.
25. RED CLOVER
- INCI: Trifolium pratense extract
- Solubility: Hydrophilic
- Main chemical pigment(s): Formononetin
- Colour: Golden Yellow
Red clover contains high levels of isoflavones, including a natural colourant called formononetin (7-hydroxy-4′-methoxyflavone) which is dull, golden yellow in colour. Formononetin is oestrogenic in vitro and in vivo (which has yielded numerous scientific studies looking at the effects of formononetin on sheep), but little information exists on the best time to harvest red clover fields to maximise content of the isoflavones.
26. RED SANDALWOOD
- INCI: Pterocarpus santalinum extract
- Solubility: Hydrophobic
- Main chemical pigment(s): Santalin
- Colour: Red
The red obtained from Pterocarpus santalinum or red sandalwood is a complex molecule known as santalin. There are a number of forms of this basic structure all of which give quite intense red colours. The stability of this red is quite good compared to the others. It has been traditionally used for many centuries. The chemicals in Red Sandalwood either yield a red colour (Santalin A or Santalin B), or a yellow colour (Santalin Y).
27. ROSEHIP
- INCI: Rosa canina fruit oil
- Solubility: Lipophilic
- Main chemical pigment(s): Lycopene, Beta-carotene
- Colour: Red / Orange
The colour of rosehip oil extracted by cold pressing is characterised by its reddish pigmentation, which is associated with carotenoid content. In contrast, the solvent-extracted oil has a yellowish colour, which could be due to the ability of the organic solvent to extract pigments and several other substances from the seeds, and/or to the degradation of the red pigment owing to the high temperature of the oil extraction process. Nine carotenoids are found in rosehips: three carotenes (lycopene, ζ-carotene, β-carotene) and six xanthophylls (neoxanthin, trans-violaxanthin, cis-violaxan-thin, 5,6-epoxylutein, lutein, β-cryptoxanthin). This high number of compounds classifies these fruits among those with the greatest variety of carotenoid pigments. Rose hips contained the highest concentrations of total carotenoids, which are mainly comprised of lycopene and beta-carotene.
28. SAFFLOWER
- INCI: Carthamus tinctorius seed oil
- Solubility: Lipophilic (Carthamin), Hydrophilic (Carthamidin)
- Main chemical pigment(s): Carthamin
- Colour: Yellow / Red
Safflower contains a pigment called carthamin, which is a yellow-orange colour. On closer examination it is shown to contain two natural colourants, one yellow, the other red. The seeds yield an oil and the flowers give a yellow dye. Carthamin produces a water-insoluble red dye and carthamidin produces a water-soluble yellow colour dye.
29. SAFFRON
- INCI: Crocus sativus extract
- Solubility: Hydrophilic
- Main chemical pigment(s): Crocin, Crocetin, Picrocrocin, Riboflavin
- Colour: Yellow
The dried stigmas and tops of the styles of the Crocus sativus contain crocines, crocetins and picrocrocine and safranal. They are delicate colours and should be protected from light. The stigmas of C. sativus are rich in riboflavin, a yellow pigment and vitamins. In addition, saffron contains crocin, the major source of yellow-red pigment. α-crocin is a carotenoid pigment which is primarily responsible for saffron’s golden yellow-orange colour. The bitter glycoside picrocrocin is responsible for saffron’s flavour. Safranal is responsible for the aroma of the saffron. Not to be confused with the autumn crocus Colchicum autumnale, which is poisonous.
30. SEA BUCKTHORN
- INCI: Hippophae Rhamnoides Fruit Oil
- Solubility: Lipophilic
- Main chemical pigment(s): Beta-carotene, zeaxanthin, lycopene
- Colour: Orange
The main pigments that give sea buckthorn berry its distinctive colour are carotenoids. These compounds are present in high amounts in pulp oil in particular. However, the total content of carotenoids varies (300–2000 mg/100 g) greatly between different growth locations and subspecies. In general, the main carotenoids present in sea buckthorn pulp oil are beta-carotene, zeaxanthin and lycopene.
31. SPINACH
- INCI: Spinacia Oleracea Leaf extract
- Solubility: Lipophilic
- Main chemical pigment(s): Chlorophyll
- Colour: Green / Yellow
Spinach leaves contain chlorophyll a, chlorophyll b and beta-carotene as major pigments as well as smaller amounts of other pigments such as xanthophylls. In green leafy vegetables such as spinach, only the green chlorophylls are seen because they mask the bright red, orange and yellow colours of the carotenoids. Blanching spinach reduces its percentage of chlorophyll. Chlorophyll is lipophilic.
32. SPIRULINA
- INCI: Spirulina platensis extract
- Solubility: Hydrophilic
- Main chemical pigment(s): Phycocyanin and Phycoerthyrin
- Colour: Blue / Green
Spirulina represents a biomass of cyanobacteria (blue-green algae). There are two species, Arthrospira platensis and Arthrospira maxima, which produce pigments called phycocyanin and phycoerthyrin. Phycocyanin is a blue-coloured pigment, absorbing orange and red light, and phycoerthyrin is a red-coloured pigment. Pigments of microalgal origin which are currently enjoying high market demand and spirulina falls into this category!
33. ST. JOHN’S WORT
- INCI: Hypericum perforatum flower extract
- Solubility: Lipophilic and Hydrophilic
- Main chemical pigment(s): Hypericin
- Colour: Red
Hypericin is a fluorescent red pigment found in St. John’s Wort. Although the herb produces bright yellow flowers, its macerated oil is dark red. Once these flowers have been steeped in the oil over a period of time, the oil turns a dark red which can be used in anhydrous or emulsified formulations. Along with hyperforin, hypericin is one of the best known chemical constituents in St. John’s Wort and is thought to have antibiotic, antiviral and anti-depressant properties. Hypericin has a unique molecular structure in which one-half of the molecule is hydrophilic (water loving) while the other half is hydrophobic (water repelling).
34. TOMATO
- INCI: Solanum lycopersicum extract
- Solubility: Lipophilic
- Main chemical pigment(s): Lycopene
- Colour: Red / Orange
The major constituents of the tomato are lycopene, α and β-carotene, lutein, zeaxanthin and b-cryptoxanthin. Lycopene is a bright red carotene and carotenoid pigment and phytochemical found in tomatoes and other red fruits and vegetables, such as red carrots, watermelons, gac, and papayas. Lycopene is the pigment in tomato-containing sauces and is insoluble in water. It can be dissolved only in organic solvents and oils. It constitutes about 80–90% of the total carotenoid content of red-ripe tomatoes. Beta-carotene, the yellow pigment of the carrot is the isomer of lycopene.
35. TURMERIC
- INCI: Curcuma longa extract
- Solubility: Hydrophobic
- Main chemical pigment(s): Curcumin
- Colour: Yellow / Orange
Turmeric is commonly known as Indian saffron. It consists of dried, as well as fresh rhizomes of the plant Curcuma longa. The rhizome has been used as a medicine, spice and colouring agent for thousands of years. Turmeric contains a chemical called Curcumin which will give a range of colour from yellow to a deep orange. Turmeric contains about 5% of volatile oil, resin and yellow colouring substances known as curcuminoids. Chemically turmeric contains about 50-60% curcumin, which is responsible for the yellow colour of the natural colourant.
36. WALNUT
- INCI: Juglans nigra shell extract
- Solubility: Lipophilic
- Main chemical pigment(s): Juglone
- Colour: Orange / Brown
Black walnut drupes contain juglone (5-hydroxy-1,4-naphthoquinone), plumbagin (yellow quinone pigments), and tannin. Black walnuts make a orange-brown dye. The liquid (dye) obtained from the inner husk becomes increasingly darker over time, as the outer skin darkens from light green to black. Juglone is an isomer of lawsone, which is the staining compound in the henna leaf.
37. WOAD
- INCI: Isatis tinctoria leaf extract
- Solubility: Hydrophilic
- Main chemical pigment(s): Indigotin
- Colour: Blue / Indigo
Woad is also the name of a blue dye produced from the leaves of the woad plant. The dye chemical extracted from woad is indigotin, the same dye extracted from “true indigo”, Indigofera tinctoria, but in a lower concentration. It is worth noting that woad is classified as an invasive species in parts of the United States.
38. YARROW
- INCI: Achillea millefolium oil
- Solubility: Lipophilic (essential oil)
- Main chemical pigment(s): Chamazulene
- Colour: Blue
Similar to Blue Tansy and German Chamomile, some essential oils from yarrow can contain chamazulene which gives the oil a dark blue colour. Some yarrow essential oils are dark blue and contain over 15% chamazulene, which can act as a great natural colourant for your skincare formulation.
During the steam distillation of the herb, a compound called matricine is converted to azulene or chamazulene, compounds which are not present in the actual plant. It is only through the application of heat and the process of steam distillation that azulene and chamazulene develop
VARIATION IN NATURAL COLOURANTS FOR SKINCARE
As a formulator you must keep in mind that natural ingredients are prone to variation. After all, plants vary between harvests, seasons, locations and habitats. An avocado oil produced by one supplier may have a far deeper green colour than another produced elsewhere. This means that your beautiful wheat germ oil or sea buckthorn oil may present with different colours ranging from supplier to supplier and even from batch to batch. And it may not only be your cosmetic ingredient’s colour that shows variation, but also its scent and its chemical compounds.
Working with variation in ingredients can pose a daunting challenge to any formulator – how do you make sure that your products always look, smell and behave the same? This is the main reason that the mainstream industry first strips all plant oils and extracts from their inherent colours and scents and then adds standardised (and of course not always natural) colourants and scents to the product to guarantee a reproducible and uniform colour and scent over decades.
FORMULATING WITH NATURAL COLOURANTS
Legal issues
Many of these ingredients can legally not be viewed as natural colourants in your organic skincare or haircare formulations. Certain cosmetic regulations around the world (such as those in the EU) specify a list of approved colourants to be used in cosmetics – and most of these plants will not feature on those lists.
Thankfully the vast majority of these natural colourants will have other chemical and beneficial properties for your formulations; given their chemical nature and the role they play in the plant, they are often antimicrobial, antioxidant or anti-inflammatory. In the case that your ingredient is not listed on an approved colourant list, it will be considered as a functional ingredient instead.
pH
As you’ve seen in this article, many of the plants we’ve listed contain similar chemicals that function as natural colourants – anthocyanins, carotenoids, etc. Some of these water-soluble pigments are pH dependent. In the case of anthocyanins, depending on the pH, they have a colour spectrum that ranges between dark blue to purple to red.
If you want to achieve the same colour shade and product integrity from batch to batch, then you will need to adjust your formulation’s pH to be within a narrow range.
You will also need to make sure that the pH of your product does not change during its shelf life, which is why stability testing is so important
Chelation
Chelators are often added to cosmetics to improve stability, because they stop or slow-down unstable reactions which are catalysed or promoted by metal ions. A perfect example of such a chemical reaction is a colour change.
If there are metal ions present in your formulation then they can affect the overall colour of the product by attaching themselves to the pigment molecule’s surface or replacing a particular metal ion. Adding a chelator to your formulation would cause it to bind with the metal ion and prevent unwanted colour change.
SOURCE: https://formulabotanica.com/38-natural-colourants-skincare/
