1. Hibiscus and cornflower – raw materials for natural hair dyeing
Katarzyna Pytkowska
Academy of Cosmetics and Health Care, Warsaw, Poland

2. Plant preparations for hair dyeing
Plants have been used for dyeing hair for ages
Henna (Lawsonia inermis)
lawsone, 2-hydroxy-1,4-naphthoquinone
Green shells of walnut (Juglans regia)
juglone, 5-hydroxy-1,4-naphthoquinone
German chamomille (Chamomilla recutita)
Apigenin
Indigofera tinctoria
Indigotin

3. Other plants of interest
Other plants used traditionally for hair coloration in Europe
Sweet sedge (Acorus calamus)
Rhubarb (Rheum spp.)
Oak bark
Plants containing high amount of dyes and pigments of intense shade
Hibiscus (Hibiscus sabdariffa)
Cornflower (Centaurea cyanus)

4. Mechanisms of action of plant dyes
Reactive dyeing
Maillard reaction with keratin
lawsone, juglone
Direct dyeing
Adsorption of dyes/pigments on the hair cuticle
Apigenin
Other flavonoids
Other substances

5. Hibiscus sabdariffa petals
The main ingredient of hibiscus infusions
the additive to other blends of herbs
Strong ruby-red colour and characteristic aroma

6. Colouring agents in hibiscus
flavonoids
anthocyanides, flavonols
E.g. delphinidin (1), delphinin, cyanidin (2), hibiscetin, gossipetin and their glycosides.

7. Problems with natural dyes
Natural dyes are (in solutions):
not very stable,
prone to oxidation, browning, UV discolouration etc.
highly pH sensitive
none of these adverse effects are applicable to the dry powdered material containing natural dye
but …
in-home application of packs and pastes prepared from dry herbal material could be difficult
Colour effects are sometimes dificult to predict
Colour is strongly determined by the plant

8. Factors influencing intensity and durability of color
the kind of hair and the damage intensity,
initial hair colour,
earlier application of synthetic dyes and/or bleaching products,
structure of a natural dye,
frequency of the application of plant preparation,
the temperature of dyeing mixture
duration of the mixture - hair contact

9. How to change colour coming from natural dyes?
… by complexes formation or destabilization
Mordants
Chelating agents
… by dye absorption
HMW additives to formulation

10. Our research

11. Hibiscus We used the following types of preparations for research
dyeing blend
Infusion of H. sabdariffa petals in water in proportion 1: 10, applied cold,
dyeing rinse
Infusion of H. sabdariffa petals in water in proportion 1: 20, applied warm,
dyeing pastes
thickened preparations based on the dyeing blend
The colour of the dyeing preparation strongly depends on pH

12. pH value
Colour ot the dyeing blend
3,12
Intense pink-red
3,35
Pink-red
4,80
Light pink
5,58
No colour
6,57
Light yellow
7,09
Brown-yellow
7,65
Light blue
7,90
Brown-blue
> 7,90

13. Rinse Colour effect 2x 2 min. 4x 2min. Dark brown - Medium brown +++
Golden reflexes ++
Red shade
Conditioning
+++ dominant colour, ++ additional shades, - none
Shade: +++ strong shade, ++ visible shade, + light shade, - no shade
Conditioning effect: strong, ++ good, + slight, - none

14. Paste with kaolin 20 min. 40 min. Paste with wheat bran Dark brown +++
Medium brown -
Golden reflexes +
Red shades
Conditioning effect
+++ dominant colour, ++ additional shades, - none
Shade: +++ strong shade, ++ visible shade, + light shade, - no shade
Conditioning effect: strong, ++ good, + slight, - none

15. Hibiscus Effects Slight colour effect on dark hair Strong conditioning
Adsorbents change the colour effect

16. Preparations for grey or bleached hair

17. Grey or bleached hair Problem – too yellow shade
Remain of phaeomelanin in originally blonde, grey hair
Insufficuent bleaching
Solution – optical brightening
Sorption of blue dye/pigment on the hair surface – use of blue pigment-rich raw material
Removal of red/yellow dyes from a natural raw material by sorption or complex formation
pH shift of colour (not applicable to human hair)

18. Hibiscus preparations

19. +++ dominant shade; ++ additional shade; + very light shade;
Additive
pH value
Colour uniformity
Hair shade
pink
blonde
No additive
3,17
+ + + -
Rice mash
3,25
+/ -
+ + +
Kaolin
Corn flour
3,31
Wheat bran
3,36
Oat bran
3,38
Colour uniformity
+++ uniform, even colour; +/- quite even colour ; - uneven, not uniform colour
Colour
+++ dominant shade; ++ additional shade; + very light shade;

20. Effects of inorganic additives

21. Mordants used in traditional textile dyeing
Alum (potassium aluminum sulfate)
does not affect colour strongly. It is usually used with potassium tartrate, which helps to provide evenness and will also brighten slightly.
Iron (ferrous sulfate).
It will sadden or darken colours,
Tin (stannous chloride)
blooms or brightens colours, especially reds, oranges and yellows.
Almost always used with potassium tartrate.
Not allowed for use in cosmetics
Copper (copper sulfate)
saddens colours and brings out greens.

22. Chromametric analysis L*a*b* scale

23. Hibiscus sabdariffa, pH=3,3 -5,22 -1,99 -4,32 7,06
Natural blond hair
dL*(D65)
da*(D65)
db*(D65)
dE*ab(D65)
Hibiscus sabdariffa, pH=3,3
-5,22
-1,99
-4,32
7,06
Hibiscus sabdariffa + Fe2O3; pH=3,3
-3,29
-2,02
-7,45
8,39
Hibiscus sabdariffa, pH=5,8
-3,11
1,41
-2,63
4,31
Hibiscus sabdariffa + Fe2O3; pH=5,8
-8,82
-2,34
-4,58
10,21
Hibiscus sabdariffa + Fe2O3 + trisodium EDTA
-9,07
3,77
-4,59
10,84
Hibiscus sabdariffa + trisodium EDTA
-9,72
5,99
-6,48
13,13
(Chromametr Konica-Minolta: Chroma Meter CR-400)

24. Hibiscus sabdariffa, pH=3,3 -6,19 2,42 -6,44 9,25
Bleached hair
dL*(D65)
da*(D65)
db*(D65)
dE*ab(D65)
Hibiscus sabdariffa, pH=3,3
-6,19
2,42
-6,44
9,25
Hibiscus sabdariffa + Fe2O3; pH=3,3
-12,33
-3,18
-13,15
18,3
Hibiscus sabdariffa, pH=5,8
-7,97
-4,79
-10,55
14,06
Hibiscus sabdariffa + Fe2O3; pH=5,8
-7,06
-4,63
-5,11
9,86
Hibiscus sabdariffa + Fe2O3 + trisodium EDTA
-9,99
7,71
-14,43
19,17
Hibiscus sabdariffa + trisodium EDTA
-9,67
5,72
-12,42
16,74

25. Cornflower preparations

26. Cornflower
The main blue pigment of cornflower petals is a complex compound of flavonoids and Al ion (protocyanin)

27. Cornflower preparations
We used the following types of preparations for research
dyeing blend
Infusion of cornflower petals in water, applied cold,
dyeing rinse
Infusion of cornflower petals in hot water
The infusion changed the colour to strawberry-red
The problem
The stability of Al-flavonoid complex

28. Cornflower Application on bleached hair Colour shift by mordants
Decrease of b* parameter in chromametric evaluation
Colour shift by mordants
Cu and Zn containing mordants shifted the cornflower-based colour to the blue region
The effect was similar to the effect of pure mordants

29. Conclusions Hibiscus-based raw materials should be fully applicable to
hair care cosmetics for grey and bleached hair
plant-based dyeing preparations
Cornflower is a plant of high interest
The main problem to solve is blue pigment stability in solutions

30. Acknowledgments
I would like to thank the researchers involved in the project: Stanislaw Krus MSc, Halah Faraj BSc, Sylwia Antczak BSc and Ewa Pawłowska.