HAIR DAMAGE 47 0 c• o .E rr o D Undamaged Hair [] Perre/Bleach Damaged Hair I 3 5 CONDITIONER (21nl Shampoo) (Each value is an average of three tresses. Observed differences are significant at p=O.05 level). Figure 3. Protein loss from undamaged and perm/bleach-damaged hair during combing. PROTEIN LOSS FROM VARIOUS HAIR TYPES DURING COMBING It is known that hair type influences combing ease. The fiber properties that influence ease of combing are curvature, friction, stiffness, diameter, length, and cohesion. An increase in fiber curvature (as in curly hair), friction, or static charge (dry hair) will make hair more difficult to comb, whereas an increase an stiffness, diameter, and cohesion will make hair easier to comb (17). To test whether protein loss measurements can provide meaningful results for different types of hair, three different shampoos were tested for post-shampoo protein loss due to combing. Four different hair types were used, namely, Caucasian, Asian (Indian), Oriental, and Negroid. The shampoos tested include sham- poo 5 (previously evaluated 2-in-1 prototype conditioning shampoo) vs a leading brand baby shampoo (shampoo 6), and shampoo 5 vs a leading brand 2-in-1 conditioning shampoo (shampoo 7). Results of these studies are summarized in Figures 4 and 5. As shown, protein loss due to combing was found to be significantly lower (p: 0.05) from hair treated with shampoo 5 as compared to both shampoos 6 and 7, regardless of the hair type tested. Limited combing studies on shampoos 5 and 7 also supported these observations. Wet-combing experiments showed that hair shampooed with shampoo 5 was significantly easier (p = 0.05) to comb than hair shampooed with shampoo 7 [the wet-combing scores for shampoo 5 vs shampoo 7 were 7.85 and 6.64 for virgin Oriental hair (a higher combing score implies easier combing see Materials and Methods), 7.5 and 6.6 for permed Oriental hair, and 6.61 and 3.94 for European bleached hair]. Although wet-combing studies on shampoo 5 vs shampoo 6 were not conducted, one would expect similar results because shampoo 6 is a non-conditioning shampoo and therefore would not condition hair any better than shampoo 7, which, as mentioned above, is a conditioning shampoo. In fact, one would expect that between these two shampoos (6 and 7), hair shampooed with shampoo 6 will be more difficult to comb. As

48 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS [] Shampoo 6 [] Shampoo 5 ..:. Negroid Asian (Indian) European Oriental Hair Type (Each valua Is an avarage of three tresses. Observed differences are significant at p=O.05 level). Figure 4. Post-shampoo protein loss from various hair types during combing. expected, protein loss was the highest from Negroid hair (curliest) for any given sham- poo among the three products tested (see figures). As mentioned earlier, an increase in fiber curvature makes hair more difficult to comb. Obviously, one would experience more difficulty in combing curly hair such as Negroid hair among the four hair types -5-5-5-5-5 • '" -5-5-5-5-5 o • [] Shampoo 7 [] Shampoo 5 Negroid Asian (Indian) European Oriental Hair Type (Each value is an. average of threa tresses. Observed differences are significant at p=O. 05 lavel). Figure 5. Post-shampoo protein loss from various hair types during combing.