478 JOURNAL OF COSMETIC SCIENCE
The conditioner containing tara provides better wet feel and better dry feel compared to
the base conditioner or guar. No difference in the ease of wet combing and the ease of dry
combing were observed between the three formulas.
Tara is an excellent film former and thus can be used in styling formulations. Tara forms a
continuous translucent film with no tackiness, good flexibility, and adhesiveness compared
to guar gum. An important attribute for styling polymers is their resistance to high
humidity, which is measured with a high humidity spiral curl retention (HHSCR) test.29
Gels made with 1 wt% tara or 1 wt% guar gum were applied to tresses and the HHSCR
was measured according to the previously described method. After 24 hours at 90% RH
and 25°C, 58% of the spiral curl length was retained with tara compared to 49% with
guar, which indicates that tara can provide better spiral curl retention and a more resistant
hold compared to guar at high humidity. The increase in humidity resistance for tara
relative to guar is likely due to lower galactosyl substitution in tara, which is less disruptive
when packing the polymer chains.
Another important property of hair styling products is the amount of stiffness that the
formulation or polymer can provide to the hair as it relates to the feel perceived by the
consumer. The results show that using 1 wt%, 1.5 wt% and 2 wt% of tara mucilage
leads to stiffnesses of 3.0 ± 0.3 N, 3.1 ± 0.6 N, and 3.7 ± 0.5 N, respectively. Increasing
the amount of tara does not significantly increase the stiffness. Tara gives medium-to-low
stiffness with high hold properties even at high humidity, thus making it ideal for styling
formulations with a touchable, natural-looking style.
Thanks to its film-forming properties and characteristics (nontacky film due to its high glass
transition temperature of 220°C), tara can be used in styling formulations where a claim
against pollution is made. Indeed, tara limits the adhesion of particles to the hair fibers
and acts as a shield as demonstrated in the test performed using the previously described
procedure. Figure 27 shows hair tresses untreated or treated with 0.5 wt% tara for which
a statistically significant reduction of particle adhesion by 50% is observed (p 0.001).
Figure 27. Hair tresses before and after contact with particles, untreated (a) or treated with tara (b).

479 DELIVERING SUSTAINABLE SOLUTIONS TO IMPROVE WELLBEING
Combining tara with other synthetic or natural polymers can enable synergistic behavior.
Combining tara with acrylate polymers like carbomer or acrylates/C10-30 alkyl acrylate
crosspolymers (Carbopol® Ultrez 10 and Carbopol® Ultrez 21 polymers, respectively,
commercially available from Lubrizol, Brecksville, Ohio, USA) result in strong viscosity
synergy, enable the formulation of high viscosity styling gel, and minimize the amount
of synthetic polymer. The addition of a very small concentration of acrylates/C10-30 alkyl
acrylate crosspolymers to 1 wt% tara leads to a much higher viscosity than expected if
an additive behavior was considered (Figure 28). Indeed, a mucilage containing 0.1 wt%
acrylates/C10-30 alkyl acrylate crosspolymers and 1 wt% tara reaches 25,300 mPa·s while
individual viscosities obtained are 4,150 mPa·s and 6,120 mPa·s, respectively. This synergy
may be due to the ability of tara to hydrogen-bond with the acrylate polymers.
Combining tara with diutan gum (Kelco-Care™ diutan gum, commercially available from
Lubrizol, Brecksville, Ohio, USA in partnership with CP Kelco, Atlanta, GA, USA) allows
for the formulation of a wide range of product viscosities with superior styling properties
while also maintaining smooth textures and low flaking. Indeed, diutan gum exhibits very
high humidity resistance but relatively low viscosity on its own compared to tara. Thanks to
the synergistic viscosity behavior when combining both gums, it is possible to create a styling
gel that is suitable for a tube format with a low total amount of polymers (1 wt% tara and
0.5 wt% diutan gum) and excellent hold (76% HHSCR). Alternately, 1.5 wt% tara and 0.75
wt% diutan gum may be used to obtain a gel adapted to jar packaging. The combination
of tara and diutan gum leads to translucent styling gels with touchable, humidity-resistant
hold based on natural-based polymers with a wide possible range of viscosities.
Tara also exhibits strong synergy with a quaternized cassia polymer where the synergistic
behavior is not limited to a viscosity boost, but also provides a dramatic increase in
stiffness. For example, a combination of 1 wt% tara and 1 wt% quaternized cassia leads
to a measured stiffness of 12.8N while having a viscosity of 20,000 mPa·s and a smooth
texture. This combination opens the possibilities to formulate naturally derived, extreme
Figure 28. Viscosities of 1 wt% tara, and 0.1 wt% acrylates/C10-30 alkyl acrylate crosspolymer gels used
individually or combined.