HAIR DAMAGE PREVENTION BY COCONUT OIL 333 Table I Analysis of Variance for Treatment Effects Hair type Source of variance Degrees of freedom* Sum of squares Mean square F-Value DeMeo Between treatments 7 3545687.30 506526.76 156.76 Experimental error 192 620411.57 3231.31 Straight Between treatments 7 35050625.20 500723.60 37.80 Experimental error 192 2543128.50 13245.46 Wavy Between treatments 7 3071240.99 438748.71 28.39 Experimental error 192 2967233.28 15454.34 Curly Between treatments 7 2729734.30 389962.04 21.839 Experimental error 192 3429503.00 17861.99 * F theoretical for degrees of freedom (7,192) at 95% confidence level = 2.01. Table II Analysis of Variance for Half-Head Treatments and Their Significance Hair type Source of variance Degrees of freedom* Sum of squares Mean square F-Value Normal Between treatments 1 51724.87 51724.87 413.70 Experimental error 38 4751.07 125.03 Bleached Between treatments 1 259854.40 259854.40 654.89 Experimental error 38 15077.94 396.79 * F theoretical for degrees of freedom (1,38) at 95% confidence level = 4.08. Table III Pair-Wise Comparison of Treatment Effects* Treatment DeMeo Straight Wavy Curly Undamaged: with and without coconut oil 6.55 1.73 8.26 5.26 Undamaged: without coconut oil and bleached 17.55 2.35 26.24 9.63 Undamaged: without coconut oil and boiled 5.21 4.59 32.99 1.83 Bleached and treated with boiling water 16.02 7.43 2.26 10.00 Coconut oil-treated bleached and coconut 32.07 13.16 4.93 16.88 oil-treated treated with boiling water Bleached coconut oil-treated and treated 10.28 8.85 17.04 7.04 with boiling water coconut oil-treated Treated with boiling water and coconut 6.33 0.06 0.91 0.81 oil-treated treated with boiling water Treated with boiling water and treated 1.51 1.91 1.70 1.26 with boiling water coconut oil-treated Bleached and coconut oil-treated bleached 6.91 3.85 7.29 1.82 Bleached and bleached coconut oil-treated 13.22 3.91 8.63 3.47 * Student's t-test theoretical for 48 degrees of freedom at 95% confidence level = 1.645. Protein-loss measurements were also used to highlight the beneficial effect of coconut oil as a prewash conditioner for different commercial shampoos (instead of 20% SLES). Seven different brands were used in this study involving Indian curly and straight hair. Protein-loss data in Figures 5 and 6 once again show that combing damage is alleviated by coconut oil used as a conditioner. Curly hair shows a greater trend towards protein

334 JOURNAL OF COSMETIC SCIENCE 400 -r I.• 35o o • 3 O0 ::} 2 50 z t ) 200 160 Z lOO I-- 50 o cL o 348,86 366-67 264,9 234,99 242'26 244__,68 z 203.5 -- !03.50 -- 201,08 t91.38 -- 176.85 162'32 150.20 1 57,37 • 1 2 3 4 5 6 7 SHAMPOO BRANDS Without Coconut Oil [•'•Jwith Coconut Oil as Prcwash Figure 5. Reduction of protein loss by prewash treatment with coconut oil on curly hair washed with various commercial shampoos. 350• 300 250 200 150 100 50 o 30 4.7 264,1 209,56 194,25 192,23 153.27 172.2 15%.63 51.2 5 • 145.09 139.94 139.62 139.3 • • • 121'.t 1 2 3 4 5 6 7 SHAMPOO BRANDS With Coconut Oil [] With Coconut Oil cts Prewash I Figure 6. Reduction of protein loss by prewash treatment with coconut oil on straight hair washed with various commercial shampoos.