Stabilization of Chinese Gallnut (Galla Chinensis) Tannins by Spray-Drying Microencapsulation for Natural Hair Coloring

Utilisation of Tectona grandis (teak) leaf extracts as natural hair dyes

“…However, colour fading within the first three shampooing actions illustrates the low fastness property of teak leaf extracts, which requires the combined use of mordants to improve the durability of the colour shade. For example, using ferrous sulphate as a mordant with natural dyes provided good fastness properties against washing and light, as previously reported with henna and Chinese gallnut extracts 26,35 …”

“…For example, using ferrous sulphate as a mordant with natural dyes provided good fastness properties against washing and light, as previously reported with henna and Chinese gallnut extracts. 26,35 To improve the durability of the colour shade of teak leaf extracts on the hair, the best conditions of the extracts obtained from the dyeing ability test in this study will be selected to investigate the effects of using mordanting agents with teak leaf extracts in a future study.…”

Recent Advancements in Natural Plant Colorants Used for Hair Dye Applications: A Review

“…When hydrolysable tannins (pale yellow color) are complexed with iron (II) ions, a strong bluish-black color is produced and the coordination complex formed between tannin, mordant and hair fiber can enhance the color fastness [16]. Both gallotannins and gallic acids occur abundantly (tannin content over 65%) in Galla Chinensis (Chinese gallnut) and the gallnut extract was widely used as a black hair dye with iron (II) sulfate in eastern Asia [44]. Sargsyan et al [36] studied the hair dyeing mechanism of matcha, which contains another type of hydrolysable tannin, catechin, and found a similar iron-gall complex formed between the mordanting iron (II) ions and the hydroxy groups of flavanol and keratinous hair fiber [79].…”

“…Tang et al used maltodextrin and gum Arabic as wall materials to prepare microcapsules of extracted colorants from Chinese gallnut and henna by spray drying techniques. The encapsulation of gallnut extract significantly improved the photo-and thermal-stabilities as well as formulation stability in alkaline formulation while the encapsulation of henna extract remarkedly reduced its contact toxicity without affecting the hair dyeing properties [17,44]. Therefore, encapsulation technology has provided a route to solve the stability and compatibility issues addressed in natural dyeing with plant colorants.…”