HAIR DAMAGE PREVENTION BY COCONUT OIL 331 zoo 350 300 2 50 200 •5o 100 so 366,67 321.73 g 30& .7 , 26/-,.07 • 264.00 • 26/,,90 160.66 136,6 g DeMeo St rctig ht Wavy Cur ly HAl R TYPES With Coconut Oil [] Without Coconut Oil Figure 2. Comparison of protein loss in wet combing for undamaged hair. Clearly, the protein loss is significantly reduced by the application of coconut oil as a prewash conditioner (coconut oil applied before SLES wash). The same trend is also observed in the case of bleached hair and hair treated with boiling water (Figures 3,4). •.• 700 600 500 100 300 200 •00 0 622.75 574-23 •//•, 577.10 5•,2, 02 • ß525.05 514'84511.68 51 0.19 ß 127. 57 ß ß 3 8 6.08 , ß ß ß ß ß ß ß ß ß ß ß ß DcMeo Straight Wavy Curly HAIR TYPES I [•Without Coconut Oil r•With Coconut Oil as Postwash r']With Coconut Oil as Prewosh ] Figure 3. Protein loss in wet combing of bleached hair with coconut oil as pre- and postwash conditioner.

332 JOURNAL OF COSMETIC SCIENCE 450 aO0 350 300 •5o 200 150 Z loo • so n o 396.65 $386,26 303,82 • i 343.6 231.03 189.&2 • 175.46 1•0.50 174,43 ß o DeMeo Straight Wavy Curly HAIR TYPES J l•Jwithout Coconut Oil J•J With Coconut Oil as Postwash J--J With Coconut Oil as Prewash J Figure •. Protein loss from hair treated with boiling water and the ef[bct of coconut oil as a conditioner. With these two damaged samples, coconut oil was also used as a postwash conditioner (coconut oil after SLES wash) in addition to use as a prewash treatment. The difference between the results of the prewash and postwash treatments reflects the relative impor- tance of fiber lubrication on cuticle loss. From the point of view of combing damage, limiting the swelling of the fiber appears to be more beneficial than just lubricating the swollen fiber. As in the laboratory test, the beneficial effect of coconut oil was also observed in a salon test. A significant difference in protein loss was observed with (13.1 pg/g) and without (203.02 pg/g) coconut oil for normal hair. For bleached hair, the corresponding values were 304.8 and 466.0 pg/g, respectively, for treatments with and without coconut oil. The beneficial effect of coconut oil in preventing cuticle damage in the laboratory test was established statistically by analysis of variance (ANOVA). The outcome of the analysis is shown in Table I. F-values clearly indicate that damaged as well as undamaged hair benefit from application of coconut oil as a prewash conditioner. The effects of coconut oil were also positive in the salon test, as can be seen from the data in Table II. In both normal and bleached hair, treatment effects in reducing protein loss are sig- nificant. This is also seen in pair-wise comparison using the t-test. The data is shown in Table III. In this table, there are four outcomes that are not statistically significant. They are comparisons of hair treated with boiling water for 2 hr (without any treatment) with hair treated with coconut oil after treating with boiling water for 2 hr. This clearly shows that the cuticle damage has occurred in the hair treated with boiling water for 2 hr before the application of coconut oil.