Infrared synchrotron
radiation absorption
spectroscopy

Development of Hair-Care Products
from Rice Water

Research method

Visualizing the penetration of a protective compound into the hair using spectroscopy

Role of SPring-8

Achievements

Development of a technique to observe the penetration of a protective
ingredient into the hair
Demonstration of the effect of inositol, an ingredient of rice water, on protection
and beautification of the hair
Development of new hair-care products containing inositol
R&D facility: Kracie Home Products, Ltd.

*Fluorescence imaging: An observation technique using fluorescence microscopes to detect fluorescently-labelled molecules, such as fluorescein
isothiocyanate, that have been introduced into proteins.
**Infrared microspectrometer: This device combines features of an infrared spectrophotometer and microscope; it can measure the distributionsof test ingredients. Powerful infrared synchrotron radiation available at the SPring-8’s Infrared Materials Science (BL43IR) beamline allows detailed
measurements of the distributions of ingredients in the cross-section of individual hairs.

Hair-protective and -beautifying effects of inositol
Inositol, which is an ingredient of rice water, has the capability torepair damaged hair, as well as protect the hair from damage.

BackgroundResults

Evaluation of modern hair-care products
requires not only characterization of sensory
features, such as improvement in the feel andgloss of the hair, but also scientific explanation of
the mechanisms by which the active ingredientsexert their effects. Inositol, a carbohydrate
contained in rice water, has been used as ahairdressing in Japan since the 8th century. This
compound has been demonstrated to haveprotective and beautifying effects on the hair.
Fluorescence imaging* has been used toobserve the penetration processes of the active
ingredient as it exerts its hair-beautifying effects.
However, the quantification of the effects wasdifficult, and inositol’s hair-beautifying mechanisms
remain unknown.

The infrared microspectrometer** at SPring-8,
which uses infrared synchrotron radiation, canexamine the subtle differences between the interiorsof healthy and damaged hair. Examination of hair
onto which inositol was applied revealed that signals
originating from chemical bonds specific to inositol
are stronger near the hair surface, but decreasetoward the hair center, indicating that inositol
penetrates into the hair gradually. Additionally, wedemonstrated that inositol stays inside the hair,allowing its protective and beautifying effects topersist even after rinsing.
Based on this result, new hair-care products
containing inositol are being developed. The
wisdom of ancient people has contributed
extensively to these developments.

Permeability of inositol into the hair
Numbers in the legend of the figures below represent theabsorption intensity of infrared synchrotron radiation. A larger
number indicates that there are more chemical bonds specific toinositol. The figure on the right, in which warm colors are highly
visible, shows that the inositol concentration is higher along theouter contour of the hair (dashed line). This is the first-everquantitative visualization of the penetration and persistence ofinositol, a hair-protecting ingredient, into the hair.

InositolProtective effects

Protective effects

Damage-promoting factor

Damages3) Surface friction (While rinsing)1) Surface (Hair dye)2) Inside (Permanent wave, “Perm”)

0.189

0.16

WorsenImprove
0.134

0.142

0.14
0.12
0.10Healthy hair

Damaged hair

Inositol treatedSuppressing the worsening of hair elasticity due todamage from perms (Protection).

8Friction → High

Hysteresis ratio

Elasticity → High

0.18

Dynamic friction coefficient (μk)

Untreated
0.20

Inositol treated

1.2
0.964

1.0

0.819

0.8
0.6
0.4

WorsenImprove

0.334

0.2
0.0

Healthy hair

Damaged hair

Inositol treatedSuppressing damage from friction during rinsing(Protection).

- 0.36- 0.36- 0.32- 0.32- 0.28- 0.28- 0.24- 0.24- 0.20- 0.20- 0.16- 0.16- 0.12- 0.12- 0.08- 0.08- 0.04- 0.045μm

5μm

Inositol stays inside the hair even after rinsing,resulting in continuing protective
hair-beautifying effects!

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